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Biodiesel production from crude rice bran oil and properties as fuel
Abstract
This research reported on the successfully production of biodiesel by transesterification of crude rice bran oil (RBO). The process included three-steps. Firstly, the acid value of RBO was reduced to below 1 mg KOH/g by two-steps pretreatment process in the presence of sulfuric acid catalyst. Secondly, the product prepared from the first process was carried out esterification with an alkaline catalyst. The influence of four variables on conversion efficiency to methyl ester, i.e., methanol/RBO molar ratio, catalyst amount, reaction temperature and reaction time, was studied at this stage. The content of methyl ester was analyzed by chromatographic analysis. Through orthogonal analysis of parameters in a four-factor and three-level test, the optimum reaction conditions for the transesterification were obtained: methanol/RBO molar ratio 6:1, usage amount of KOH 0.9% w/w, reaction temperature 60 °C and reaction time 60 min. In the third step, methyl ester prepared from the second processing step was refined to become biodiesel. Fuel properties of RBO biodiesel were studied and compared according to ASTM D6751-02 and DIN V51606 standards for biodiesel. Most fuel properties complied with the limits prescribed in the aforementioned standards. The consequent engine test showed a similar power output compared with regular diesel but consumption rate was slightly higher. Emission tests showed a marked decrease in CO, HC and PM, however, with a slight increase in NOX.
... This idea could be taken advantage of by blending with FAME derived from lipids of longer chain lengths and higher saturation to improve the CN of BD from RBL. However, actual tests of FAME from RBL following ASTM D 613 resulted in CN ranging from 48 to 61 [45][46][47]. Although no strict standards are set for cold flow properties, FAME from RBL have favorable cold flow properties suitable for use in the tropical (T ≥ 18°C) and the subtropical (T = −3 to 22°C) zones, where Southeastern Asian countries and part of Southern and Eastern Asian countries are located. ...
... Step [46] observed from the works of Mumtaz et al. [47] and Prabu et al. [90]. This is because KOH is available at lower purity (~85%) and higher molecular weight than NaOH. ...
... An increase in temperature during the transesterification step resulted in reduced reaction time allowing a high degree of conversion (> 95%) within a total reaction time of 8 to 10 h. An alternative approach is to reduce the FFA content to less than 1% with 0.5 to 1 wt% H 2 SO 4 via a single or 2-step esterification process, and use alkali catalyst in the subsequent transesterification step to convert the remaining AGs, following typical alkali catalyzed transesterification [46,[96][97][98]. Generally, the total time required for the reactions ranged from 2 to 3.5 h, which is much lesser than using a single catalyst. ...
The biodiesel (BD) industry struggles to compete with petroleum diesel because of its high cost, primarily attributed to the costs of raw material and production. Rice bran (RB) is an oleaginous agro-industrial residue which has been of interest as a feedstock for BD production. Although RB has been found to be a potential resource for various products of commercial interest, its current bulk but limited utilization is either as a source of edible oil or as an ingredient of feeds. A key challenge in processing lipids from rice bran is its significant free fatty acid content but is not necessarily a setback when utilized for biodiesel production. Despite the perceived potential, the sheer number of published researches, and even patented processes, there has been no quantitative assessment of the resource availability, and no commercialized process reported. In this work, a localized resource assessment with biodiesel yield estimates has been conducted to identify priority areas for adapting rice bran for biodiesel production. As leading paddy rice producers, Southern, Eastern, and Southeastern Asian regions were found to have potential in adapting RB as a biodiesel feedstock. Alongside this, detailed technological comparisons were described in this review, from lipid extraction, reaction systems or schemes, reactants, catalysts, reactor configurations and strategies, to emerging and patented technologies with economical and scalable potential. In addition, opportunities in (RB) processing and related government policies, foreseen impacts on economics, social, and environmental aspects, as well as existing challenges, were identified and discussed for future prospects and developments.
... Each of vegetable oil has different fatty acids composition, saturated and unsaturated. The dominant fatty acids composition of RBO oil are oleic acid, linoleic acid, and palmitic acid (Table 1) [3], [5], [6]. Previous studies has simulated glycerol production as byproduct biodiesel production from corn oil [7]. ...
... The application of catalysts in the transesterification process is crucial. Sodium hydroxide was frequently used as a catalyst for this process [5]. Metal oxide utilization as a catalyst in transesterification reaction to produce biodiesel is also extensively researched [2], [4]. ...
... After separation process, the crude biodiesel produced was around 114 L/h. The simulation product properties comparison to Lin et.al study [5] and Sinha and Agarwal study of biodiesel production from rice bran oil conducted at 55C and oil to alcohol molar ratio 1:9 [15] shown in Table 3. The density of simulation result is similar with both studies, but the viscosity is much lower. ...
... Several studies related to the acid esterification of oils with high FFA content can be found in the literature [22,23]. In the study developed by Lin et al. [22], the production of biodiesel in two steps started with a pretreatment by acid esterification using a 6:1 methanol:oil molar ratio for 60 min at 50 • C, achieving a reduction in acidity from 40 to 4.8 mg KOH g −1 . ...
... Several studies related to the acid esterification of oils with high FFA content can be found in the literature [22,23]. In the study developed by Lin et al. [22], the production of biodiesel in two steps started with a pretreatment by acid esterification using a 6:1 methanol:oil molar ratio for 60 min at 50 • C, achieving a reduction in acidity from 40 to 4.8 mg KOH g −1 . Using rice bran oil, in the second stage (alkaline transesterification reaction), it was possible to produce biodiesel with a high purity (around 98.7% of fatty acid methyl esters). ...
Rice is one of the most consumed cereals in the world. From rice processing, rice bran is obtained, and only a part of this by-product is effectively used. Rice bran oil can be obtained and used as an alternative feedstock for biodiesel production, although few studies exist to support its exploitation. In addition, pretreatment is required to reduce its acidity and allow for its integration in the conventional industrial process. This work evaluated two pretreatment processes aiming to reduce the free fatty acid (FFA) content of rice bran oil by employing an acid-catalyzed process and a biocatalyzed process. The results allowed us to assess the efficiency and effectiveness of both pretreatments. For that purpose, acid (45, 55 and 65 °C, using H2SO4 concentrations of 2 wt.% or 4 wt.% and a methanol:oil molar ratio of 9:1) and enzymatic FFA conversion (35 °C using a 6:1 methanol:oil molar ratio and 5 wt.% of Thermomyces lanuginosus) were evaluated using rice bran oil with an acid value around 47 mg KOH.g−1, and the reaction kinetics were assessed. Acid esterification enabled a 92% acidity reduction (65 °C, 4 wt.% of catalyst) after 8 h, with the final product presenting an acid value of 3.7 mg KOH.g−1 and a biodiesel purity of 42 wt.%. The enzymatic process allowed an acidity reduction of 82%, resulting in a product with an acid value of 7.0 mg KOH.g−1; however, after 24 h, the biodiesel purity was 87 wt.% (almost a two-fold increase compared to that obtained in the homogeneous process), revealing the conversion of both free fatty acids and glycerides. The study of the reaction kinetics of the homogeneous (acid) esterification showed that, for temperatures > 45 °C, the constant rate increased with temperature. A higher constant rate was obtained for the temperature of 55 °C using 4 wt.% of catalyst (k′ = 0.13 min−1). For the heterogeneous (enzymatic) esterification, the constant rate obtained was lower (k′ = 0.028 min−1), as expected. The study revealed the technical viability of the esterification pretreatment of rice bran oil and the important parameters concerning the performance of the pretreatment solutions. Finally, the enzymatic process should be further explored, aiming to develop more ecofriendly processes (water and energy savings) to produce biodiesel from oils with a high acidity (low-cost raw materials).
... For confirmation, we tried to keep methanol ratio constant with an increased ratio of oils and observed that there was no significant difference in the yield of biodiesel (2B). Higher methanol to oil mass ratio increment leads to the conversion of glycerol and biodiesel back to triglycerides (glycerolysis) and thus the biodiesel yield decreases 10 . Similar find- ings were observed by Modiba et al. 11 . ...
The lack of conventional fossil fuels and the increase of the polluting emissions generated by combustion have increased the necessity for alternative fuels, such as biodiesel. Huge efforts have been carried out in recent years in order to develop an alternative fuel from renewable resources. Biodiesel production has received considerable attention in the recent past as a biodegradable and nonpolluting fuel. The production of biodiesel by the transesterification process employing alkali catalyst has been industrially accepted for its high conversion and reaction rates. The use of cooking oil as raw material is a very interesting alternative for the production of biodiesel. Further, to reduce production cost, in the present research, restaurant waste vegetable oil was used as the feedstock. The effects of methanol as solvent to oil molar ratio and reaction time and temperature on the production of biodiesel were investigated. The results indicated that methanol as solvent, 3:1 methanol: oil molar ratio was found to be optimum at 60°C and 400 rpm. Under these optimal conditions, the conversion of free fatty acids to fatty acid methyl esters was found to be 89%. The crucial biodiesel properties of waste vegetable oil are within the American standard test method specifications.
... Globally, vegetable oils are part of the traditional food chain for humans, though some researchers are discovering growing applications for biodiesel from them by transesterification (Issariyakul and Dalai, 2014;Lin et al., 2009). Soya beans or soybeans is considered in this study due to its health benefits, which include preventing heart attack and stroke, helping to fight cancer, aiding the digestive system, helping with good blood circulation and helping to treat insomnia. ...
This study addresses the need for a more environmentally friendly and sustainable alternative to hexane, the conventional solvent for oil extraction. Hexane, while efficient in dissolving oil, poses neurotoxicity risks and stems from nonrenewable sources. In contrast, ethanol, produced via biotechnological methods, offers a promising alternative due to its minimal environmental impact, cost-effectiveness, and safety profile. The objective of this work is to compare the performance of hexane and ethanol in the extraction of soybean oil, employing simulation techniques rather than traditional laboratory experiments. The research develops a mathematical model for a countercurrent multistage solid-liquid extraction process, specifically tailored for soybean oil extraction, and simulates the process using MATLAB/SIMULINK. The results reveal that hexane exhibits a higher initial extraction rate, especially over a 90-minute simulation period, though ethanol demonstrates comparable efficiency. Moreover, ethanol consistently showcases higher extraction efficiency relative to hexane when considering solvent-to-solid mass ratios. In conclusion, both hexane and ethanol extraction prove practical with ethanol holding advantages in terms of safety and extraction efficiency. These simulation findings serve as a valuable foundation for subsequent laboratory experiments which can contribute to the validation and refinement of the simulation model.
... Rice bran oil has been attracting a lot of attention among waste-oriented feedstock and nonedible oil feedstocks due to its potential to reduce biodiesel production costs [4]. Several countries, including Bangladesh, Vietnam, India, China, and Indonesia, primarily use rice bran as animal feed or the use of solid fuel as a low-cost source of energy [5,6]. Rice bran can contain up to 32 wt% oil depending on the type of rice and method of milling. ...
In day-to-day life, fossil fuels play an important role in transportation and power generation. The consumption of fossil fuels increasing rapidly with increase in emission from engines. Due to habituation over fossil fuel, both the economy and environment are suffering. The researchers are in the position to find the best alternative for fossil fuels. The employment of biodiesel is taken to be the classy replacement for this snag. According to scores of research, using additions of nanoparticle is the greatest way to control emissions and improve engine performance. Here the assessment was employed though rice bran (RB) oil, rice bran oil blended with aluminum oxide (RB Al2O3), and rice bran oil blended with cerium oxide (RB CeO2). Rice bran oil is extracted and converted into biodiesel by transesterification process. And the nanoadditives are prepared using the two-step method. The addition of nanoadditives showed an improved performance in the engine as well as emission parameters. The congruent assessment clearly demonstrates the improvement of brake thermal efficiency by around 28% for RB-Al2O3 and an improved brake-specific fuel of 16%. Both the blends exhibit good part loading traits.
... Raw materials must be pretreated to separate water and other contaminants before being fed directly into the transesterification reactor, making the reactor inlet contain triglycerides and fatty acid alkyl esters produced from the esterification process. The most common catalyst used in transesterification reactions is NaOH in aqueous form, so it can be mixed directly with the feed stream as it enters the reactor [28]. When acid esterification reactions are involved, additional base catalysts may be required to neutralize the acid. ...
Cottonseed oil (CSO) is well known as one of the commercial cooking oils. However, CSO still needs to compete with other edible oils available in the market due to its small production scale and high processing cost, which makes it a potential candidate as a feedstock for biodiesel production. To date, transesterification is the most widely applied technique in the conversion of vegetable oil to biodiesel, with glycerol produced as a by-product. Large-scale biodiesel production also implies that more glycerol will be produced, which can be further utilized to synthesize hydrogen via the steam reforming route. Therefore here, an integrated biodiesel and hydrogen production from CSO was simulated using Aspen Hysys v11. Simulation results showed that the produced biodiesel has good characteristics compared to standard biodiesel. An optimum steam-to-glycerol ratio for hydrogen production was found to be 4.5, with higher reaction temperatures up to 750 °C resulting in higher hydrogen yield and selectivity. In addition, a simple economic analysis of this study showed that the integrated process is economically viable.
... The process of transesterification that makes use of a catalyst is referred to as a catalytic transesterification process, whereas the process that does not make use of a catalyst is referred to as a non-catalytic transesterification process (Gerpen, 2005;Meher et al., 2006;Marchetti et al., 2007). In addition, a catalytic process might be one of two categories: homogeneous or heterogenous, and this classification is determined by the catalyst that is being employed (Fjerbaek et al., 2009;Lin et al., 2009). It has been reported that the heating value of biodiesel made from microalgae is 41 MJ/kg (Xu et al., 2006) and this value is in accordance with the ASTM D6751 standards . ...
Microalgae are a vital resource for the coming years to address the concern of decrease in oil reserves and the negative impacts of fossil fuels on the environment. Their utilization is crucial for a wide range of industrial applications. Depending on the strain, microalgae contain a variety of chemical components and can be treated biochemically or thermochemically. This review thus focuses on the biochemical mechanisms that are used to convert algal biomass into sustainable fuel, including the challenges and potential of those processes. Microalgae have been shown to be a viable third-generation alternative to conventional biofuel feedstocks. The optimum production of biofuel depends on the proper selection of microalgae species based on their lipid, carbohydrate, and protein content in order to produce high-quality, sustainable biofuel. Nannochloropsis gaditana can contribute to a maximum biodiesel yield of 96.47%, whereas Nannochloropsis oculata can produce the least (25%) through the biochemical process of transesterification. Higher yields of microalgae-derived gaseous, solid and liquid fuels can be achieved by pre-treating microalgal biomass and then employing bioconversion processes such as photo-fermentation and hydrothermal carbonization.
... Rice bran oil can also be used as an edible oil in recent times and as a raw material to produce biofuels and environmentally friendly lubricants [5][6][7][8][9][10][11]. Recently, a series of tribological and rheological studies have been conducted on rice bran oils [12][13][14][15][16][17][18][19]. ...
Due to their excellent characteristics, vegetable oils are successfully used in various formulations of organic lubricants. In this context, the advanced biodegradability and excellent lubricity performance of rice oil leads to its being considered as a real potential for the lubricants industry. However, as with other vegetable oils, the stability of rice bran oil is strongly influenced by the oxidation process. Therefore, the aim of this work was the oxidation stability monitorization of rice bran oil by spectrophotometric techniques. For this purpose, oxidation tests of rice bran oil at elevated temperatures were performed.In this paper, transmittance spectra were determined, and the trichromatic components and coordinates were calculated, as well as the colour differences for rice oils subjected to a forced oxidation treatment at temperatures of 100 °C and 120 °C for 4, 8 and 10 hours. The results obtained show that, although after the first 4 hours of forced oxidation significant changes appear on the physicochemical properties of rice bran oil, an increase in the test time from 8 to 10 hours does not lead to significant changes in the analysed parameters, the conclusion being valid for both test temperatures.
... Vietnam, China, India, Indonesia, and Bangladesh use rice bran as animal feed or for burning as fuel. Rice bran contains 18-22 wt% of oil [4,5]. Rice bran oil can be used in the production of bakery foods as it improves the quality of cooking [5]. ...
Rice bran is rich in oil and constituted by a lignocellulosic structure, which is a potential raw material for its processing into several products. Therefore, the oil yield and composition of oil obtained from supercritical CO2 extraction were investigated to select a condition for using defatted rice bran for processing by subcritical water hydrolysis. The effects of temperature (230 °C and 260 °C) and solvent-to-feed mass ratio (50 and 100 g water/g defatted rice bran) on fermentable sugar yield (YFS) and hydrolysate composition were evaluated and discussed. Supercritical CO2 extraction at 40 °C and 20 MPa provided an oil yield of 17.19 wt% at 120 min. For defatted rice bran, the highest YFS (6.53 g sugars/100 g defatted rice bran) was obtained at 260 °C and 100 g water/g defatted rice bran.
... The presence of catalysts in the transesterification process is critical. Sodium hydroxide is known as a conventional catalyst for this process [48]. Heterogeneous catalysts based on metal oxide is also broadly researched in transesterification reaction for the potential application as catalyst to generate biodiesel [49,50]. ...
Indonesia is one of the largest rubber producers worldwide. However, rubber seeds still garner less attention due to their low economic value. In fact, the rubber seeds contain 40–50% (w/w) of rubber seed oil (RSO), which is a potential candidate to be used as a feedstock in biodiesel production. In this regard, this study aims to model and simulate the production process of biodiesel from RSO via transesterification reaction, employing methanol and heterogeneous catalyst. The simulation was performed using ASPEN Hysys v11. Acid-based catalyzed esterification was implemented to eliminate soap formation, which may significantly lower biodiesel yield. The results showed that an RSO inlet rate of 1100 L/h with a methanol to oil molar ratio of 1:6 could generate around 1146 L/h biodiesel. Methanol recovery was conducted, an approximately 95% of excess methanol could be regenerated. Simulation results indicated that the properties of the biodiesel produced are compatible with modern diesel engines. Economic analysis also shows that this technology is promising, with excellent investment criteria.
... It was observed that the optimal conversion efficiency was obtained at a methanol to oil ratio of 30wt%. With increase in methanol to oil ratio the yield reduces due to fact that the glycerol remaining in the solution drives the equilibrium back to left side of the reaction [12]. ...
... The molar ratio of oil to methanol in the transesterification process is an important factor that determines the yield of methyl ester (Lin et al., 2009). In the following transesterification operations, the oil-to-methanol ratio was changed as follows: The rest of the parameters were held constant during the reaction: 1:4, 1:6, 1:9, 1:12, 1:15, and 1:18. ...
In this work, Dodonaea oil was studied as a potential biodiesel source. Dodonaea (Dodonaea viscosa Jacq.) is an evergreen shrubby plant that thrives in tropical and subtropical conditions. The plant produces high-grade biodiesel in terms of both quantity and quality despite its naturally high fat content. In the transesterification followed by esterification reaction, varied ratios of oil to methanol, constant temperature (60°), reaction duration (1 h), and different catalyst concentrations (0.25–0.75% (w/w) were utilized. A maximum biodiesel yield of 90% was achieved. For fuel characteristic analysis, the prepared biodiesel was specified and compared to ASTM criteria. The chemical composition was verified using analytical techniques such as FT-IR and NMR spectroscopy. As a result of the foregoing, Dodonaea is considered a possible bioenergy source, particularly in the transport sector.
... Rice production in Brazil in the 2020/2021 harvest was 11.75 million tons (CONAB, 2021). Some countries such as China and India use rice bran as animal feed or as low-cost fuel (Lin et al., 2009). In addition, rice bran is also used for oil extraction in food industries. ...
Deffated rice bran has potential to processing into ethanol due to its lignocellulosic composition and agricultural productivity. The composition of the pretreated deffated rice bran with Deep Eutectic Solvent was investigated aiming the production of sugars and bioproducts using subcritical water hydrolysis. Changes in the deffated rice bran composition at different pretreatment times and mixtures of deep eutectic solvent were evaluated by the derivative of thermogravimetric analysis. The pretreated deffated rice bran presented an enrichment in the content of hemicelluloses (281.0%) and delignification (59.3 %). Under the same condition of subcritical water hydrolysis (230 °C/ R-100) the yield of fermentable sugars increased 2.20 times in the same study time interval (20 min) when comparing pretreated and untreated deffated rice bran.
... It appears that the methanol tends to enhance the solubility of glycerin causing the glycerolysis. This is not favoured since the ester reacts with the glycerol to form monoglyceride (Lin et al. 2009). Apparently there is no appreciable relationship between the reaction duration and reaction temp. ...
Euphorbiaceae, the spurge family has 6745 species in 218 genera. Though they are cosmopolitan in occurrence, they are distributed primarily in the tropics and are xerophytes. Many of these species carry milky latex, and some are useful as a source of oil or wax. Out of the huge number of species 8 of them are observed to be useful as resource in biodiesel production and hence dealt in this chapter. Out of the above, 5 (Aleurites moluccanus, Croton megalocarpus, Hevea brasiliensis, Jatropha curcas and Vernicia montana) belong to a single subfamily Crotonoideae. Other 3 species belong to Euphorbioideae (Euphorbia lathyris and Triadica sebifera) and Acalyphoideae (Ricinus communis).
... It is a by-product of the milling process, weights up to 8% of harvested rice heads. Hence, rice bran oil is having a positive attraction for biodiesel (Lin et al. 2009). The current experimental research on diesel engine using various fuels reveals that biodiesel secures the first position in all due to less HC and CO emission characteristics and better performance (Goga et al. 2019;Jayaprabakar and Karthikeyan, 2019;Prabhu et al. 2019). ...
Substantial growth in emissions, hike in fuel prices, and exhaustion of fossil fuels has given rise to the need for substitute fuels for diesel engines, which are renewable and demote the emission. Also, strict international emission standards force researchers to seek alternative fuels. Vegetable oils are promising alternative biodiesel for a diesel engine, amongst them, rice bran is underutilized, a non-edible source that doesn’t create any food security hurdle. The paper focused to investigate the performance, combustion, emission, and vibration characteristics of diesel engine fuelled with rice bran biodiesel and n- butanol additive (5% constant) at CR 17.5. The engine characteristics of seven biodiesel blends (B5n5, B10n5, B15n5, B20n5, B25n5, B30n5, and B40n5) were measured at various loads under constant speed and compared with diesel fuel. The performance characteristics were observed in moderate quantities as compared to diesel whereas the emissions were found reduced drastically than diesel fuel except for nitric oxides (NOx) emissions. The measured engine cylinder vibration for all blends indicates similar results as diesel fuel hence leads to smooth combustion. The investigation shows that blends from B20n5 to B30n5 have the potential to be used in a diesel engine without any modification.
... However, oil derived from waste biomass, waste cooking oil, and yellow grease which are associated with low cost and readily accessible; could become the potential feedstock for efficient production of biodiesel [11]. In this scenario rice bran oil (RBO) could stand as a favourable alternative which is an inexpensive co-product of rice] milling process with 15-23% oil content [12]. But the extraction of RBO from the bran is inhibited by its high ash contents, FFA, unsaponifiable components and polar lipids [13]. ...
Improvisation of the biodiesel production using low-cost feedstock and the process optimisation is the perfect measure for the mitigation of high cost associated with the production process. In this current study, we are focussing on the extraction of rice bran oil (RBO) which is mainly considered underutilised waste material for the synthesis of biodiesel. Solvent extraction of RBO was performed with the aid of ultrasound and the study of various process parameters were exhibited using design of experiment by Taguchi model. The highest extraction efficiency was obtained at S/R ratio: 4:1 (ml/g), Agitation speed: 150 (rpm), Agitation time: 60 (min), Size range: 427.5 (micron), Sonication time (min): 15 (min) and Power level: 70 (KW). It was observed that the ultrasound-assisted extraction produced better quality oil than the extraction performed by conventional Soxhlet. Secondly, the esterification was performed using sulphuric acid as the acid catalyst and parametric optimization was performed for the enhancement of biodiesel yield using L9 orthogonal array. The key factors viz. agitation speed of 1000 rpm, methanol to oil ratio (M/O) of 10:1and reaction temperature of 60 °C; were found to be favourable for the attainment of the maximum yield of biodiesel.
... A yearly saving of around 102.89 billion INR (~1.38 billion USD) can be achieved, even if half of the existing parboiling practice is modified to MWP. However, the recovery cost from the by-products can additionally be expanded by utilizing bran and husk for biodiesel production [46] biogas production [47], respectively. For adopting the proposed method on an industrial scale, high MW efficiency [69] and less manpower requirement (owing to lesser processing steps) will further reduce the production cost. ...
Parboiled rice (PBR) is extremely popular in South Asian nations however, the conventional process of parboiling performed for PBR production is energy and time intensive. In the present work, a unique approach of parboiling is proposed in which high moisture freshly harvested paddy was taken as the raw material for parboiling and the conventional hot water soaking (HWS) was replaced by microwave-assisted soaking (MWS). An in-depth comparative assessment was carried out between the conventional parboiling (CP) and the microwave-assisted parboiling (MWP) based on actual and theoretical energy consumption and feasibility of the MWP was ascertained given process economy and PBR qualities into account. An overall energy saving of 20.48% was achieved through MWS as compared to HWS. The specific energy consumption for steaming during MWP was found to be 78.22 kJ kg⁻¹ which is 48.47% lower as compared to the CP. Moreover, the overall processing time and cost of processing were reduced by 6.91 h and 1583 INR/ton for MWP in comparison to CP. From the quality point of view, MWP resulted in a lower broken percentage, higher grain whiteness and lower cooking time of the PBR produced.
... Nevertheless, the optimal yield of biodiesel among various raw oils could be attributed to many factors, such as the acid values of crude oils, the reactivity of the utilized base catalyst and mode of heating (conventional, microwave, or sonication) employed during the transesterification process. [34] Rice bran KOH Conventional 60 98.33 [55] Calophyllum inophyllumwco KOH Conventional 65.8 94.25 [44] Jatropha curcas-Ceiba pentandra KOH Conventional 120 93.33 [4] 3.8. Analysis of SF50RB50 methyl ester For analyzing the SF50RB50 methyl ester (SF50RB50ME), Fourier-transform infrared (FTIR) spectroscopy was used. ...
The present study is to investigate the feasibility of mixed non-edible oils, Sterculia foetida (SFO), and rice bran oil (RBO) for biodiesel production. The transesterification process variables of SFO50RBO50 as the suitable blend were optimized using response surface methodology. The optimum conditions of the transesterification process are as follow; KOH catalyst concentration of 0.7% wt, the ratio of methanol to oil of 42%, the reaction time of 50.64 min, resulted in the methyl ester yield of 98.93%. The result shows that the SF50RB50 methyl ester properties satisfy the biodiesel requirements laid in ASTM D6751 and EN 14214 standards.
... The use of a sustainable environmentally friendly solvent has been demonstrated as suitable for the extraction of biooil from waste generated from coffee, which is a significant cash crop traded in sub-Saharan Africa, thus using dimethyl ether (DME), to yield about 16% of biodiesel (transesterification process) (Matzen & Demirel, 2016;Sakuragi, Li, Otaka, & Makino, 2016). Also, the global attention toward the utilization of rice bran for biodiesel production draws attention to its high oil content and the massive potential to be used for sustainable production of biofuels (Lin, Ying, Chaitep, & Vittayapadung, 2009;Patil, Kar, & Mohapatra, 2016). ...
The development of renewables and alternative technologies to ensure eco-friendly measures and meet the production of natural gas shows considerable growth potential for the electrification of modern cities and isolated or rural communities. Biofuels are achieved from oil-based producing crops and other biodegradable agricultural residues and biomass feedstocks that have undergone several processes to yield alcohol, in the form of ethanol. This chapter addresses the occurrence, techniques, and strategies of biofuel production, with inference to the classification and characteristics of the fuels. A concentrated assessment of agrowaste conversion has been reported, offering vital contributions to the understanding of the properties of biofuels. This chapter contends with sustainable industrial agriculture solutions for developing countries and sub-Saharan Africa in perspective.
... There are various techniques of biodiesel production available today, such as catalytic [4,5], enzymatic [6], noncatalytic techniques [7,8] and so on. Among them, catalytic transesterification has long been a preferred method for producing biodiesel fuel. ...
The objective of this work was to investigate the transesterification kinetics for biodiesel preparation from waste cooking oil under electric field. The experiments were carried out in a batch reactor with waste cooking oil and methanol at molar ratio of 1:6 at the atmospheric pressure with 1% weight of the catalyst KOH. The product concentrations were measured during reaction process at various conditions to determine the reaction rates. The effect of operating parameters such as temperature and voltage was investigated. It turned out that the reaction completed fast in the presence of electric field, where conversion rate was remarkably raised. The charged liquid dispersion processes were also studied to reveal the mass and heat transfer mechanism for transesterification through liquid–liquid interface. By applying the Arrhenius equation, the activation energy and the frequency factor were found to be 57.71 kJ/mol and 1.39 × 107 s−1, respectively. Electric field was found to be high efficiency for biodiesel preparation enhancement.
... It is one of the critical fuel properties as it affects fuel injection in engines and sprays the atomization process [57]. Additionally, the biodiesel flashpoint of 72 • C (Table 4) was also compatible and is in line with reported work elsewhere [58,59]. ...
The rapid depletion of fossil fuel resources and climatic changes has triggered the researchers' attention to find an alternative and renewable energy source. Thus, biodiesel has been recognized as a potential alternative to petrodiesel for its biodegradability, non-toxicity, and environment-friendly attributes. In this study, an efficient and recyclable Cu–Ni doped ZrO2 catalyst was synthesized and used to produce biodiesel from a novel non-edible caper (Capparis spinosa L.) seed oil. The synthesized catalyst was characterized by x-ray diffraction, fourier-transform infrared spectroscopy, scanning electron microscopy, and energy dispersive x-ray analysis. The catalyst was reused in four consecutive transesterification reactions without losing any significant catalytic efficiency. Transesterification reaction conditions were optimized via response surface methodology based on Box-Behnken design for predicting optimum biodiesel yields by drawing 3D surface plots. Maximum biodiesel yield of 90.2% was obtained under optimal operating conditions of 1:6 M ratio of oil to methanol, reaction temperature of 70 °C, reaction time of 1.5 h, and 2.5% catalyst loading. Fourier-transform infrared spectroscopy, gas chromatography–mass spectrometry, and nuclear magnetic resonance (¹H and ¹³C) analysis confirmed the high quality of biodiesel produced from non-edible caper (Capparis spinosa L.) seed oil. The fuel properties of the produced biodiesel were also found, such as kinematic viscosity (4.17 cS T), density (0.8312 kg/L), flash point (72 °C), acid no (0.21 mgKOH/g) and sulphur content (0.00042 wt%). These properties were matched and are in close agreement with the International Biodiesel Standards of European Union (EU-14214), China GB/T 20,828 (2007), and American (ASTM6751). Thus, non-edible Capparis spinosa L. seed oil and Cu–Ni doped ZrO2 catalyst appeared to be highly active, stable, and cheap candidates to boost the future biodiesel industry.
... Biodiesel is derived from long-fatty acid triglyceride in the form of mono-alkyl esters as shown in Reaction 1, which undergoes transesterification or esterification in the presence of alcohol (methanol) [29][30][31][32][33][34]. ...
Biodiesel is an attractive fuel replacement for diesel engine in Malaysia. The application of biodiesel as fuel-blend has been implemented commercially in transport sector in the country. Among various potential feedstock for biodiesel production, microalgae have been appeared as a promising source since a decade due to its' high biomass productivity, rapid growth rate, large amount of lipid content, capability of high CO 2 capture and sequestration as well as suitable geographical location to be harvested. The main objective of this study was to determine the feasibility of microalgae harvesting in Malaysia to produce biodiesel and potential to implement microalgae-biodiesel as commercial transportation fuel. This study demonstrated the current scenario of overall biodiesel production and application in Malaysia. Since Malaysia is the world's second-largest oil palm producer, exploitation of edible palm oil for the making of biodiesel is to be blamed as the cause of soaring food price; therefore, the country is currently looking for 3rd generation biofuel sources and microalgae has been preferred for this purpose. Therefore, insight of the significance of microalgae cultivation for this purpose, suitable microalgae candidates and possible feasibility of microalgae biodiesel have been delineated in this review study. Prospects and challenges to implement microalgae biodiesel have also been emphasized in this study. Therefore, the advantages and limitations of this biodiesel can be transparent to government and non-government sectors. Thus, this study can redirect both sectors in future. Consequently, it may contribute setting an appropriate government policy to encourage microalgae for biodiesel production to sustain the local biofuel and secure economic growth, energy security and improve environmental conditions in near future.
This study addresses the need for a more environmentally friendly and sustainable alternative to hexane, the conventional solvent for oil extraction. Hexane, while efficient in dissolving oil, poses neurotoxicity risks and stems from nonrenewable sources. In contrast, ethanol, produced via biotechnological methods, offers a promising alternative due to its minimal environmental impact, cost-effectiveness, and safety profile. The objective of this work is to compare the performance of hexane and ethanol in the extraction of soybean oil, employing simulation techniques rather than traditional laboratory experiments. The research develops a mathematical model for a countercurrent multistage solid–liquid extraction process, specifically tailored for soybean oil extraction, and simulates the process using MATLAB/SIMULINK. The results reveal that hexane exhibits a higher initial extraction rate, especially over a 90-min simulation period, though ethanol demonstrates comparable efficiency. Moreover, ethanol consistently showcases higher extraction efficiency relative to hexane when considering solvent-to-solid mass ratios. In conclusion, both hexane and ethanol extraction prove practical with ethanol holding advantages in terms of safety and extraction efficiency. These simulation findings serve as a valuable foundation for subsequent laboratory experiments which can contribute to the validation and refinement of the simulation model.
Biofuels are renewable fuels, which can meet the demand of the recent fossil fuel crisis as well as curb the pollution rise due to population explosion. This research focuses on the utilization of aquatic plants as a raw material for the production of biofuel. In this regard, water hyacinth is considered for the investigation. Water hyacinth is also known as Eichhornia crassipes, a biomass, that grows in water body. The plant is collected from Rachenahalli Lake of Bengaluru, India, which is synthesized as raw feedstock under optimal conditions. The method used for the production is trans-esterification where the alcohol used is methanol, and the catalyst is KOH. Using separatory funnel, the biodiesel and the glycerol are separated. The produced biodiesel is then tested in laboratory for density, viscosity, flash point, and calorific value for characterization. Later, water hyacinth biodiesel produced is compared with biodiesel standards to estimate its potential as an alternative fuel.KeywordsWater hyacinthBiodieselTransesterification
The performance of TCC for nominally flat metallic contacts has been predicted using an artificial neural network (ANN) model. Experimental inputs and outputs from a previous work of one of the authors, Tariq and Asif (2019) are employed in the ANN model to predict the results. Therefore, inputs to the model include effective thermal conductivity, Vickers hardness, reduced modulus of elasticity, RMS roughness, Average asperity slope, and contact pressure, while Solid spot conductance, drop in temperature across the border, and percentage thermal loss are the model's outputs. Experiments on the performance of thermal contact conductance are carried out, with the test results serving as target data for training the ANN model. ANN results forecasts are shown to be in good agreement with the experimental test results.KeywordsArtificial Neural NetworkPerformance PredictionThermal Contact Conductance
The rapid growth in industrialization, environmental pollution, and diminution of fossil fuels are the significant aspects that encourage researchers to seek alternative renewable fuels. The study aimed to examine the influence of the compression ratio on compression-ignition engine tested with rice-bran biodiesel and n-butanol additive. An investigation has been carried out for various compression ratios under the full load condition for fixed injection timing 30° before the top dead center. The experimental result indicates that the engine torque increases with the compression ratio for all biodiesel blends. The brake-thermal efficiency shows an increasing trend with compression ratio and blends proportion up to the B30n5 blend and a decline for the B40n5 blend. The average decrease in brake-specific fuel consumption was 14% as the compression ratio increased from 16:1 to 19:1, and brake-specific fuel consumption shows an increasing trend with blending proportion. Hydrocarbon and carbon monoxide emissions were reduced by 40% and 15%, respectively. In contrast, carbon dioxide and nitrogen oxide emissions were increased by 10% and 15%, respectively, with an increase in compression ratio from 16:1 to 19:1. High compression ratio results in high heat release and cylinder pressure. The results reveal that the rice-bran biodiesel with n-butanol additives provides comparable performance with diesel and can be used for a diesel engine without modification.
With the continuous rise in the overall population of the world, the demand of fuel has increased drastically which may lead to the depletion of natural resources in the near future. Many researchers have started taking interest to find the alternative energy resources which not only meet the fuel requirement but also reduce the pollution caused by fossil fuels. In this work, biodiesel was synthesized from the seeds of Argemone mexicana and castor oil by trans-esterification reaction. Three different blends of B20, B40, and B60, with 20%, 40%, and 60% biofuel concentration, respectively, were analyzed at varying loads on the single cylinder, Kirloskar made engine. These tests include the engine performance in terms of brake power, brake thermal efficiency, brake-specific fuel consumption, and brake-specific energy consumption. Additionally, the emission characteristics like the amount of hydrocarbon (HC), CO, CO2, and O2 present in the smoke emissions were also evaluated for the same blends with similar proportions. The tests showed remarkable results as up to 40% load, blends of both biodiesel performed in an excellent way. Brake power, brake thermal efficiency, brake-specific fuel consumption, and brake-specific energy consumption were found be 6%, 21%, 14%, and 27% different than neat diesel while operating below 40% load, however, at higher load B40 and B60 provided comparatively less value for these parameters. Similarly, diesel was found to have 14% higher release of the hydrocarbon at 60% engine load as compare to B20 blend of Argemone mexicana and castor oil.
Fuels for transportation and the need for power are two of the largest contributors to global greenhouse gas emissions. Nowadays, biodiesel has shown a ray of hope for replacing diesel to minimize the harmful emissions formed during the combustion of diesel fuel in compression ignition (CI) engines. This study has focused on the production and preparation of Jasmine oil biodiesel (JB) along with its combustion in the diesel engine. The prime contribution of the present study is to maintain the performance and reduce the harmful emissions of biodiesel blends fueled CI engine. The experiments were performed on a 1-cylinder, four-stroke diesel engine using diesel and biodiesel blends such as (JB-25, JB-50, JB-75 and JB-100 on a v/v basis) at various loads. The findings of output and emission parameters are compared with the conventional fuel (diesel) output results. In this study, Taguchi and ANOVA analysis have been performed with experimental data to model and determine diesel engines' optimum working conditions (load, compression ratio, and blending ratio) for reduced emissions with slight deterioration of performance. The obtained results revealed that engine performance was in line with diesel with JB-25 and with other ratios, the performance characteristics deteriorated. However, the rate of heat release is slightly lower with a shortened ignition delay. The primary benefit is the reduction of harmful emissions i.e. hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke. It can be concluded that Jasmine oil biodiesel would be a suitable fuel for reduced engine emissions without highly affecting engine performance.
Biohydrogen generation from various waste materials is quite promising in renewable energy exploration. Biohydrogen is a cost-effective biofuel that produces both water vapor and energy when burned. However, biohydrogen production is more appreciable in utilizing various waste materials, thereby compromising both socioeconomic and technical strategies of energy exploration. The substrate, inoculum employed and their concentrations, culture kinds, and pretreatment procedure have all been found to be important in biohydrogen production. Physiological variables such as pH, temperature, redox potential, and partial pressure also significantly impact biohydrogen generation. The utilization of several growth factors, mainly the substrate, nitrogen, and phosphorus, also confronts extensive applications during biohydrogen production. This present study explores the enhancing activity engaged by the parameters and focuses on the inhibitory effects of the operating conditions.
Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day. To overcome the energy crisis, biofuel production from non-edible plant seeds is the best solution for the present era. In the present study, we select the non-edible seeds of Acacia farnesiana for biofuel production from different areas of Pakistan with better oil production results. Different kinds of analytical method, like the American Standard for Testing and Materials and techniques like Fourier transform infra-red spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography, and inductively coupled plasma optical emission spectrometry, were used to evaluate the chemical compositions. The maximum oil extraction rate (23%) was produced by petroleum ether. Potassium hydroxide exhibited the best conversion result of 96% fatty acid methyl ester. The transesterification method was used for the preparation of fatty acid methyl ester (96%) using potassium hydroxide and methanol. The viscosity and density of Acacia farnesiana seed oil biodiesel was comparable to American Standard for Testing Material biodiesel standards. By using gas chromatography-mass spectrometry, five fatty acids were detected comprising palmitic acid (6.85%), stearic acid (2.36%), oleic acid (12.13%), linoleic acid (46.85%), and α-linolenic acid (1.23%). This study concludes that Acacia farnesiana seed oil biodiesel could be an intriguing raw material for yielding Acacia farnesiana seed oil methyl ester as an alternative fuel source.
Herein, a pH-switchable Pickering interfacial biocatalysis (PIB) system is proposed and applied to a solvent-free biphasic biocatalysis. The oil-in-water emulsion was stabilized by amine-functionalized hollow mesoporous silica nanospheres (HMSS-N), which is functioned as emulsifiers of PIB and carriers of lipase AYS. The smart emulsifiers exhibited switch of the surface wettability behaviors in response to abrupt changes of pH. Under the optimality conditions, the immobilized lipase loading amount, activity, and expressed activity were 174.1 mg g-1, 9073 U g-1, and 52.1 U g-1 protein, respectively, at pH 6. Based on it, the hydrolysis of rice bran oil and esterification with phytosterols to produce phytosterol esters (PEs) were successfully performed. Compared with the conventional free enzyme one-phase system, the PIB system displays a higher reaction efficiency (catalytic efficiency value 6.88 mmol g-1 h-1, 20-fold enhancement). In addition, the system maintains 95% residual activity after 10 reaction cycles with 38.3 g products/g biocatalyst average productivity, complying with the requirements of industry-accepted standards. In each cycle, the demulsification is realized simply by in situ pH regulation. Therefore, this paper provides a powerful and green platform for oil-fat modification and stimuli-responsive interfacial biocatalysis with the advantages of a high efficiency, sustainability, a solvent-free process, and multi-recyclability.
Dilute acid hydrolysis was employed to generate lipid-dense post-hydrolyzed rice bran (PHRB) which was utilized as feedstock in biodiesel production. Upon drying of the wet PHRB with the entrained dilute acid solution, subsequent carbonization and sulfonation occurred with the material, incorporating significant amounts of sulfur in PHRB as sulfonic acid. The collected dry PHRB was utilized as feedstock in the in-situ (trans)esterification (ISTE) of its lipids to fatty acid methyl esters (FAME), whereby the available acid sites reduced the acid catalyst to be loaded in the reaction system. The optimum reaction conditions under ambient pressures were determined via the Taguchi method and the highest yield achieved was 22.38 ± 0.28 g FAME/100 g PHRB (82.31% conversion or reaction yield), and was achieved at 65 °C, SSR of 20 mL methanol/g dried PHRB, 12 h reaction time, and 5 wt% H2SO4 of the PHRB processed. The post-ISTE PHRB was found to still possess the catalytic activity and could be used for the esterification of oleic acid and methanol and appreciable stability. Finally, the FAME-rich product also exhibits free-radical scavenging activity, owing to the presence of bioactive components, which may provide better oxidative stability or could be further recovered as high-value by-products.
In this study, two approaches for biodiesel production from microalgae, one through a dry route (using dried microalgae) and another through a wet route (using wet microalgae), are critically assessed. Analysis suggests that although both routes yield biodiesel of similar quality, but there is a considerable difference in overall energy consumption, energy-intensive steps, and size of equipments for processing the same amount of lipids. This review depicts that both routes demand significant amount of energy, i.e. up to 120 MJ kg of biodiesel that amounts to nearly three times the energy obtained from it. Also, the cost of production for one kg of biodiesel is high, i.e. up to $ 25 and $ 12 in dry and wet route respectively. This review article aims to present comprehensively and coherently the technical intricacies of these two routes and their attributes in terms of energy consumption, operating expenses, and capital investment.
Obtained from rice bran oil refining process, rice bran oil fatty acid distillate (RBOFAD) is a low-value, non-edible, and unwanted by-product, which can be used as a promising alternative raw material for biodiesel production. However, the conventional biodiesel process cannot handle this material due to the high content of free fatty acid (FFA). A novel supercritical process for biodiesel synthesis using dimethyl carbonate (DMC) as acyl acceptor in a microreactor was proposed in this work for the raw material with high FFA. High quality of biodiesel and value-added by-product (glyoxal) were obtained in our process. In this process, the biodiesel content of 80.9% was achieved for the case of RBOFAD as feedstock, compared to only 43.6% for the case of refined rice bran oil as feedstock. The influence of operating conditions on biodiesel and glyoxal content including reaction temperature, residence time, and DMC-to-RBOFAD molar ratio was investigated and optimized via response surface methodology. The biodiesel content of 97.1% was achieved at the optimal conditions (reaction temperature of 360 °C, residence time of 35 min, and RBOFAD-to-oil molar ratio of 11:1). The required pressure and the amount of DMC were significantly reduced compared to other processes. Most of the biodiesel properties met the international standards except for some impurities (mono- and diglycerides). These results provided the new insight for the development of biodiesel production from low-grade feedstocks.
Several valuable products can be obtained from lignocellulosic biomass. Bioprocessing of lignocellulosic biomass to biofuels is discussed in this chapter. Bioethanol, Biodiesel and Biogas are covered.
Production of biodiesel from renewable sources has come to stay. The usefulness of biodiesel over the fossil diesel in combating the environmental degradation caused by fossil diesel combustion is a major reason for the continuous production of biodiesel. The usefulness of biodiesel over fossil diesel includes its biodegradability, higher flash points hence safer to transport and the production of far lesser carbon iv oxide gas during combustion. However, the high cost of biodiesel production is a challenge that should be considered. In this study, the cost analysis of the production of a liter of biodiesel produced from Jatropha curcas seed oil is presented in this study. The best economic way for biodiesel usage to mitigate the environmental challenges caused by fossil diesel are also highlighted.
The critical problem that arises from the production of fuel from fossil sources has stimulated recent interest in alternative sources for petroleum‐based fuel. An alternative fuel should be technically feasible, readily available, environmentally acceptable, and techno‐economically competitive. Biodiesel, which is considered a potential replacement for conventional diesel fuel, is commonly composed of mono‐alkyl ester of long chain that can be prepared from triglycerides available in renewable feedstock (vegetable oils or animal fats) utilizing transesterification technology. The feedstocks used for the production of biodiesel mainly come from edible vegetable oil, which is highly available in most countries around the world. However, the competition between food and fuel economies for the same oil resources may bring global imbalance to the food supply and demand market. The drawbacks of homogeneous catalysts involve corrosion of the reactor, difficulties in catalyst separation, consumption of the catalyst during reaction, and production of wastewater. The conventional catalysts have strong active sites and are cheap, but the difficulty in their separation from the reaction product is a trending issue that needs to be addressed. To overcome the drawbacks and limitations of heterogeneous catalysts, magnetic nanocatalysts and bio‐based catalysts are often utilized due to their ease of separation, high activity, recyclability, and large surface area. This chapter focuses on recent developments in biocatalysts based on biochar from different agricultural wastes and their applications in producing biodiesel from discarded feedstocks.
The energy sector in Brazil produces liquid biofuels as bioethanol and biodiesel. The most common technique to produce biodiesel is the transesterification of oils extracted from biomass. Rice processing generates grain bran, an agricultural residue. Brazil is one of the main countries that produce this grain. Therefore, the objective of this study was to produce a renewable biofuel using vegetable oil from grain bran via homogeneous basic transesterification. There are only three experimental studies reported in the literature on the production of biodiesel from rice bran oil via alkaline transesterification. Furthermore, the studies do not include results regarding biodiesel acidity, iodine, saponification and moisture content. Although potassium hydroxide (KOH) is the most commonly deployed alkaline catalyst in industrial biodiesel production, there are no reports regarding ethyl biodiesel production using rice bran oil with this catalyst. Therefore, this study applied a factorial arrangement in the experimental phase to produce ethyl biodiesel from rice bran oil using KOH as a catalyst on transesterification. The factors including reaction time, alcohol/oil molar ratio and amount of catalyst allowed to determine the best conditions for biodiesel production. To determine the viability of the biodiesel production, it was necessary to analyze the main parameters required by the national standards, which were kinematic viscosity, iodine index, acidity index, saponification index and moisture. All the yielded biodiesel were complied with the standards of ANP, ASTM and EN, except kinematic viscosity, which ranged from 8.061 to 22.791 mm²s⁻¹. According to the conditions of the factorial arrangement, the calculated kinematic viscosity indicated the need to raise the proportion of catalyst and/or the molar ratio between ethanol and KOH The lower kinematic viscosity, around 8–9 mm²s⁻¹, occurred with 1.5% catalyst and, in general, with molar ratio 9:1. These results suggest that future studies could explore the production of high-quality ethyl biodiesel using rice bran vegetable oil. According to the results, it represents a viable possibility to produce fully renewable and sustainable biodiesel within the socio-economic, environmental and agricultural context in Brazil.
In this work, comparative assessment of predicted biodiesel yield using response surface methodology (RSM) and artificial neural network (ANN) is implemented. The artificial neural network was trained using RSM based experimental data. The importance of each independent variable on the response was evaluated using sensitivity analysis. This study shows that ANN and RSM models closely predicted the yield with an R² value of 99.7 and 99.2 respectively. However, the ANN model precisely predicted the biodiesel yield with the least mean square error value of 0.00033, which is significantly lower than the yield predicted using RSM. The ANN simulation results show good agreement with experimental data. It can be inferred that ANN is a better tool compared to RSM and can be used for accurately predicting biodiesel yield that thereby effectively reducing the time-consuming and expensive experimental test.
Growing global warming and climate change shifted energy policy to adopt a cleaner and more sustainable way of energy generation across the world. Biodiesel has emerged as a good alternative fuel due to advantages like diesel-like structure and less emission. However, the cost of biodiesel production makes it ineffective compare to the use of diesel especially in a developing country like India. Waste materials as an alternative can help to reduce the cost. In this review rice by-products like rice bran oil and rice husk have been discussed as a cheap and reliable alternative for feedstock and source of catalyst respectively. The Rice bran oil-based biodiesel and Rice husk-based catalyst are briefly discussed using process variables like reaction temperature, yield, etc. Also, the applicability of rice bran biodiesel using engine performance and emission characteristics of biodiesel from rice bran oil is compared and the potential of by-products in India is investigated. Biodiesel production using rice bran oil as a source of free fatty acid and rice husk as a source of catalyst is discussed thoroughly. In conclusion, the rice by-products as input appeared as a good and sustainable alternative for biodiesel production in India.
A data-driven model is used to analyse the global effects of biodiesel on the energy-water-food (EWF) nexus, and to understand the complex environmental correlation. Several criteria to measure the sustainability of biodiesel and four main limiting factors for biodiesel production are discussed in this paper. The limiting factors includes water stress, food stress, feedstock quantity and crude oil price. The 155-country model covers crude oil prices ranging from USD10/bbl to USD160/bbl, biodiesel refinery costs ranging from -USD0.30/L to USD0.30/L and 45 multi-generation biodiesel feedstocks. The model is capable of ascertaining changes arising from biodiesel adoption in terms of light-duty diesel engine emissions (NO, CO, UHC and smoke opacity), water stress index (WSI), dietary energy supply (DES), Herfindahl-Hirschman index (HHI) and short-term energy security. With the addition of potential biodiesel production, the renewable energy sector of global primary energy profile can increase by 0.43%, with maximum increment up to 10.97% for Malaysia. At current crude oil price of USD75/bbl and refinery cost of USD0.1/L, only Benin, Ireland and Togo can produce biodiesel profitably. The model also shows that water requirement varies non-linearly with multi-feedstock biodiesel production as blending ratio increases. Out of the 155 countries, biodiesel production is limited by feedstock quantity for 82 countries, 47 are limited by crude oil price, 20 by water stress and 6 by food stress. The results provide insights for governments to set up environmental policy guidelines, in implementing biodiesel technology as a cleaner alternative to diesel.
Abstrak
Proses produksi biodiesel dari dedak padi dengan memanfaatkan microwave secara in situ telah berhasil dilakukan. Pengaruh jumlah metanol dan waktu reaksi terhadap kandungan FAMEs dalam produk dipelajari dalam penelitian ini. Dedak padi , metanol dan katalis basa berupa NaOH 0.6 w% dimasukkan ke dalam labu alas datar dilengkapi dengan kondensor dan dimasukkan ke dalam reaktor microwave yang telah dimodifikasi. Produk reaksi yang berupa campuran FAMEs, gliserol, reaktan yang tidak bereaksi dan komponen lainnya kemudian dicuci menggunakan n- heksana dan dilanjut dilakukan proses distilasi. Hasil penelitian menunjukan bahwa dengan menggunakan reaktor microwave, kandungan FAMEs lebih tinggi diperoleh dengan waktu reaksi yang lebih singkat. Gelombang mikro berhasil mempercepat terjadinya reaksi transesterifikasi. Kandungan FAMEs tertinggi yaitu 6.2036 % diperoleh pada waktu reaksi 10 menit, metanol 60 ml dan suhu reaksi 60oC.
Kata kunci : Biodiesel, In situ, Microwave, Dedak padi
Abstract
The process of biodiesel production from rice bran using in situ microwaves has been successfully carried out. The effect of the amount of methanol and reaction time on the FAMEs content in the product was studied in this study. Rice bran, methanol and alkaline catalyst in the form of 0.6 w% NaOH are put into a flat bottom flask equipped with a condenser and put into a modified microwave reactor. The reaction product in the form of a mixture of FAMEs, glycerol, unreacted reactants and other components is then washed using n-hexane and contuining with the distillation process. The results showed that by using a microwave reactor, a higher FAMEs content was obtained with a shorter reaction time. Microwaves successfully accelerate the transesterification reaction. The highest FAMEs content of 6.2036% was obtained at a reaction time of 10 minutes, methanol 60 ml and reaction temperature 60oC.
Keywords: Biodiesel, In situ, Microwave, Rice bran
The main objective of the present work is to work on optimization of process parameters in acid value minimization of biodiesel produced from rubber seed oil (RSO) using Al2O3/Calcined Eggshells as a heterogeneous catalyst. Optimization of process parameters was performed using response surface methodology (RSM) and artificial neural network (ANN). Acid value of raw RSO is reduced from 67.6 (mg KOH/g oil) to 2.97 (mg KOH/g oil) and later it has been reduced to 0.33 (mg KOH/g oil) in the synthesized biodiesel. Form the ANOVA analysis of RSM studies, it is observed that the designed quadratic model and the parameter methanol: oil molar ratio (mol/mol) are significant. ANN model with best validation performance of 0.00065251 at epoch-2 is observed. On comparison of coefficient of regression R2 value of 0.8885 for RSM studies and 0.9939 for ANN studies it was noticed that ANN is the best fit model with minimum error.
Our research work mainly focuses on the examination of properties, both physical and chemical, of bio diesel blends among neat diesel at different volumetric proportions. Properties like viscosity; calorific value (CV); pour point (PP); cetane number; could point (CP); flash point and fire point are measured for each blending ratios, and it is examined against the relevant standards (USA ASTM D 6751; Europe EN:14214 as well as India IS:15607). Plot between the properties and different blending ratios is drawn, and regression equations (R2) are formulated from which bio diesel properties are predicted and compared by mineral diesel. From this investigation, the optimal blending ratio is projected considering the different properties of bio diesel.
In many engineering applications, natural fibers are used because of high
strength, low weight, and easy availability. Inmany composite studies reveals among
the various natural fibers, the coir fiber is used as a reinforcing agent in polymer
composites. In this paper, the mechanical and chemical properties of the hybrid
polymer composites reinforced with coconut coir fiber and wood powder at different
fractions were studied. The hand layup technique is used for sample preparation
as per ASTM D638-03 standards. The mechanical and chemical properties such as
tensile strength, flexural strength, and impact strength and water absorption capacity
of the hybrid polymer composite were tested for different specimens prepared as per
ASTM D638-03 standards. The results of the above tests prove that the coir fiber and
wood powder have a significant influence on the mechanical properties of the hybrid
polymer composite.
Rice (Oryza sativa L.) bran contains valuable nutritional constituents, which include lipids with health benefits. A germplasm collection consisting
of 204 genetically diverse rice accessions was grown under field conditions and evaluated for total oil content and fatty
acid (FA) composition. Genotype effects were highly statistically significant for lipid content and FA profile (P<0.001). Environment (year) significantly affected oil content (P<0.05), as well as stearic, oleic, linoleic, and linolenic acids (all with P<0.01 or lower), but not palmitic acid. The oil content in rice bran varied relatively strongly, ranging from 17.3 to 27.4%
(w/w). The major FA in bran oil were palmitic, oleic, and linoleic acids, which were in the ranges of 13.9–22.1, 35.9–49.2,
and 27.3–41.0%, respectively. The ratio of saturated to unsaturated FA (S/U ratio) was highly related to the palmitic acid
content (r
2=0.97). Japonica lines were characterized by a low palmitic acid content and S/U ratio, whereas Indica lines showed a high
palmitic acid content and a high S/U ratio. The variation found suggests it is possible to select for both oil content and
FA profile in rice bran.
The production of simple alkyl FA esters by direct alkali-catalyzed in situ transesterification of the acylglycerols (AG) in soybeans was examined. Initial experiments demonstrated that the lipid in
commercially produced soy flakes was readily transesterified during agitation at 60°C in sealed containers of alcoholic NaOH.
Methyl, ethyl, and isopropyl alcohols readily participated in the reaction, suggesting that the phenomenon is a general one.
Statistical experimental design methods and response surface regression analysis were used to optimize reaction conditions,
using methanol as alcohol. At 60°C, the highest yields of methyl ester with minimal contamination by FFA and AG were predicted
at a molar ratio of methanol/AG/NaOH of 226∶1∶1.6 with an approximately 8-h incubation. An increase in the amount of methanol,
coupled with a reduced alkali concentration, also gave high ester yields with low FFA and AG contamination. The reaction also
proceeded well at 23°C (room temperature), giving higher predicted ester yields than at 60°C. At room temperature, maximal
esterification was predicted at a molar ratio of 543∶1∶2.0 for methanol/AG/NaOH, again in 8 h. Of the lipid in soy flakes,
95% was removed under such conditions. The amount of FAME recovered after in situ transesterification corresponded to 84% of this solubilized lipid. Given the 95% removal of lipid from the soy flakes and
an 84% efficiency of conversion of this solubilized lipid to FAME, one calculates an overall transesterification efficiency
of 80%. The FAME fraction contained only 0.72% (mass basis) FFA and no AG. Of the glycerol released by transesterification,
93% was located in the alcoholic ester phase and 75 was on the post-transesterification flakes.
Biodiesel is gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats. It is produced by transesterification in which, oil or fat is reacted with a monohydric alcohol in presence of a catalyst. The process of transesterification is affected by the mode of reaction condition, molar ratio of alcohol to oil, type of alcohol, type and amount of catalysts, reaction time and temperature and purity of reactants. In the present paper various methods of preparation of biodiesel with different combination of oil and catalysts have been described. The technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized. In addition, fuel properties and specifications provided by different countries are discussed.
This work reports on the preliminary results of using several acidic and basic solids, such as ZrO2, ZnO, SO42−/SnO2, SO42−/ZrO2, KNO3/KL zeolite and KNO3/ZrO2 as heterogeneous catalysts for crude palm kernel oil (PKO) and crude coconut oil (CCO) transesterification with methanol. It was found that ZnO and SO42−/ZrO2 exhibited the highest activity for both PKO and CCO transesterification. In the case of SO42−/ZrO2, only 1 wt.% of this acidic solid was needed to catalyze the reaction, and resulted in fatty acid methyl esters content higher than 90%. Moreover, a study of the catalyst's recyclability indicated that the spent SO42−/ZrO cannot be directly reused for the transesterification. However, this spent catalyst can be easily regenerated and the same activity can be obtained.
Biodiesel is an alternative fuel for diesel engines consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats. Most of the biodiesel that is currently made uses soybean oil, methanol, and an alkaline catalyst. The high value of soybean oil as a food product makes production of a cost-effective fuel very challenging. However, there are large amounts of low-cost oils and fats such as restaurant waste and animal fats that could be converted to biodiesel. The problem with processing these low cost oils and fats is that they often contain large amounts of free fatty acids (FFA) that cannot be converted to biodiesel using an alkaline catalyst. In this study, a technique is described to reduce the free fatty acids content of these feedstocks using an acid-catalyzed pretreatment to esterify the free fatty acids before transesterifying the triglycerides with an alkaline catalyst to complete the reaction. Initial process development was performed with synthetic mixtures containing 20% and 40% free fatty acids, prepared using palmitic acid. Process parameters such as the molar ratio of alcohol, type of alcohol, acid catalyst amount, reaction time, and free fatty acids level were investigated to determine the best strategy for converting the free fatty acids to usable esters. The work showed that the acid level of the high free fatty acids feedstocks could be reduced to less than 1% with a 2-step pretreatment reaction. The reaction mixture was allowed to settle between steps so that the water-containing alcohol phase could be removed. The 2-step pretreatment reaction was demonstrated with actual feedstocks, including yellow grease with 12% free fatty acids and brown grease with 33% free fatty acids. After reducing the acid levels of these feedstocks to less than 1%, the transesterification reaction was completed with an alkaline catalyst to produce fuel-grade biodiesel.
The production of fatty acid methyl esters (FAME) from crude tobacco seed oil (TSO) having high free fatty acids (FFA) was investigated. Due to its high FFA, the TSO was processed in two steps: the acid-catalyzed esterification (ACE) followed by the base-catalyzed methanolysis (BCM). The first step reduced the FFA level to less than 2% in 25 min for the molar ratio of 18:1. The second step converted the product of the first step into FAME and glycerol. The maximum yield of FAME was about 91% in about 30 min. The tobacco
biodiesel obtained had the fuel properties within the limits prescribed by the latest American (ASTM D 6751-02) and European (DIN EN 14214) standards, except a somewhat higher acid value than that prescribed by the latter standard (<0.5). Thus, tobacco seeds (TS), as agricultural wastes, might be a valuable renewable raw material for the biodiesel production.
Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats. It consists of the monoalkyl esters formed by a catalyzed reaction of the triglycerides in the oil or fat with a simple monohydric alcohol. The reaction conditions generally involve a trade-off between reaction time and temperature as reaction completeness is the most critical fuel quality parameter. Much of the process complexity originates from contaminants in the feedstock, such as water and free fatty acids, or impurities in the final product, such as methanol, free glycerol, and soap. Processes have been developed to produce biodiesel from high free fatty acid feedstocks, such as recycled restaurant grease, animal fats, and soapstock.
Environmental concerns are driving industry to develop viable alternative fuels from renewable resources. On the other hand, to reduce food surplus, the Agricultural Policy of the European Union (EU) obliges the European farmers to leave a percentage of the arable land as set-aside, where can be grown, as an exception, vegetables for nonfood purposes, i.e., energetic ones. Currently, fossil fuels are used in diesel engines and are essential in industrialized places. In addition, petroleum-based diesel increases environmental pollution. To solve these problems, transesterified vegetable oil that has been grown in set-aside lands can be considered to be a renewable energy resource. In this sense, this work describes the optimization of the parameters involved in the transesterification process of Brassica carinata oil. Gas chromatography was used to determine the fatty acid composition of Brassica carinata oil and its esters. Results revealed that the free fatty acid content is a notorious parameter to determine the viability of the vegetable oil transesterification process. In this sense, it was not possible to perform a basic transesterification using Brassica carinata oil with a high erucic acid content. The transesterification process of Brassica carinata without erucic acid required 1.4% KOH and 16% methanol, in the range of 20−45 °C, after 30 min of stirring. Our results suggest that the greater the presence of KOH, the lesser the methanol requirements. However, this is valid only under certain limits. Also, if the presence of KOH or methanol is lower or higher than the optimal values, the reaction either does not fully occur or leads to soap production, respectively. Based on this field trial, biodiesel from Brassica carinata oil could be recommended as a diesel fuel candidate if long-term engine performance tests provide satisfactory results.
A new approach to the synthesis of alkyl 3,3-dialkoxypropanoates, which are important intermediates in organic synthesis, starting from fatty acid esters is described. Thus, ozonolysis of methyl linoleate and methyl linolenate in alcoholic hydrogen chloride affords a reaction mixture, from out of which the alkyl 3,3-dialkoxypropanoates can be isolated by fractional distillation in 60-65% yield. Even linseed oil, which contains high amounts of linolic and linolenic acid, can be used as starting material, after conversion into the methyl esters by methanolysis. Byproducts of the ozonolysis can be oxidized to the corresponding carboxylic acids which are valuable intermediates in oleochemistry.
Currently, most of the biodiesel is produced from the refined/edible type oils using methanol and an alkaline catalyst. However, large amount of non-edible type oils and fats are available. The difficulty with alkaline-esterification of these oils is that they often contain large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin. A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed transesterification process converts the products of the first step to its mono-esters and glycerol. The major factors affect the conversion efficiency of the process such as molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed. The two-step esterification procedure converts rubber seed oil to its methyl esters. The viscosity of biodiesel oil is nearer to that of diesel and the calorific value is about 14% less than that of diesel. The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point are found out and compared with that of diesel. This study supports the production of biodiesel from unrefined rubber seed oil as a viable alternative to the diesel fuel.
A technique to produce biodiesel from mahua oil (Madhuca indica) having high free fatty acids (19% FFA) has been developed. The high FFA level of mahua oil was reduced to less than 1% by a two-step pretreatment process. Each step was carried out with 0.30–0.35 v/v methanol-to-oil ratio in the presence of 1% v/v H2SO4 as an acid catalyst in 1-hour reaction at 60°C. After the reaction, the mixture was allowed to settle for an hour and methanol–water mixture that separated at the top was removed. The second step product at the bottom was transesterified using 0.25 v/v methanol and 0.7% w/v KOH as alkaline catalyst to produce biodiesel. The fuel properties of mahua biodiesel were found to be comparable to those of diesel and conforming to both the American and European standards.
The result of the investigation on methyl esters obtained on the basis of heated refined sunflower oil and used frying oils are given in the paper. Transesterification reaction conditions that affect yield and purity of the product esters including oil quality, molar ratio of methanol to vegetable oil, type and concentration of alkaline catalyst, temperature and reaction time were examined. The methanolysis of different oils at 25 °C with 0.5–1.5% potassium hydroxide or sodium hydroxide were studied. The effect of molar ratio 4.5:1, 6:1 and 9:1 on ester yield and its quality were investigated. With 1% potassium hydroxide, temperature at 25 °C, molar ratio 6:1 and 30 min, all investigated oils were sufficiently transesterified and could be used as fuel in diesel engines.
Biodiesel has attractive fuel properties such as excellent biodegradability and lubricity, almost no emissions of sulfur oxides, PAH and n-PAH, reduced CO2, PM and CO emission, superior combustion efficiency, etc. However, burning of biodiesel generally produces higher levels of NOx emissions, primarily due to its high oxygen content. In this study, the emulsification technology has been considered to reduce the NOx emission level of fossil fuel. Biodiesel, produced by means of transesterification reaction accompanied with a peroxidation process, was emulsified to form two-phase W/O and three-phase O/W/O emulsions. The effects of the emulsification variables such as hydrophilic lipophilic balance (HLB), and water content on the fuel properties and emulsion characteristics of W/O and O/W/O emulsions were investigated in this study. The experimental results show that the surfactant mixture with HLB = 13 produced the highest emulsification stability while HLB = 6 produced the lowest emulsification stability and the most significant extent of water–oil separation among the various HLB values for O/W/O biodiesel emulsion. The kinematic viscosity, specific gravity and carbon residual of the biodiesel emulsions were larger than those of the neat biodiesel. In addition, the W/O biodiesel emulsion was found to have a smaller mean droplet size, lower volumetric fraction of the dispersed phase than the O/W/O biodiesel emulsion, and the highest heating value among the test fuels, if the water content is deducted from the calculation of the heating value.
The pyrolysis reactions of soybean, palm tree, and castor oils were studied. The pyrolytic products were analyzed by CG-FID, CG–MS, and FTIR, showing the formation of olefins, paraffins, carboxylic acids, and aldehydes. The adequate choice of distillation temperature (DT) ranges made it possible to isolate fuels with physical–chemical properties comparable to those specified for petroleum based fuels. The catalytic upgrading of the soybean pyrolytic fuel over HZSM-5 zeolite at 400 °C was also studied and has shown a partial deoxygenation of the pyrolytic products.
The methyl and ethyl esters of milkweed (Asclepias) seed oil were prepared and compared to soybean esters in laboratory tests to determine biodiesel fuel performance properties. The pour points of the methyl and ethyl milkweed esters measured −6 °C and −10 °C, respectively, which is consistent with the high levels of unsaturation characteristic of milkweed seed oil. The oxidative stabilities measured by OSI at 100 °C were between 0.8 and 4.1 h for all samples tested. The kinematic viscosities determined at 40 °C by ASTM D 445 averaged 4.9 mm2/s for milkweed methyl esters and 4.2 mm2/s for soybean methyl esters. Lubricity values determined by ASTM D 6079 at 60 °C were comparable to the corresponding soybean esters with average ball wear scar values of 118 μm for milkweed methyl esters and 200 μm for milkweed ethyl esters.
The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Alternative fuels, energy conservation and management, energy efficiency and environmental protection have become important in recent years. The increasing import bill has necessitated the search for liquid fuels as an alternative to diesel, which is being used in large quantities in transport, agriculture, industrial, commercial and domestic sectors. Biodiesel obtained from vegetable oils has been considered a promising option.In this paper, an attempt has been made to review the work done on biodiesel production and utilization, resources available, process(es) developed/being developed, performance in existing engines, environmental considerations, the economic aspect, and advantages in and barriers to the use of biodiesel.
Biodiesel has become more attractive recently because of its environmental benefits and the fact that it is made from renewable resources. The cost of biodiesel, however, is the main hurdle to commercialization of the product. The used cooking oils are used as raw material, adaption of continuous transesterification process and recovery of high quality glycerol from biodiesel by-product (glycerol) are primary options to be considered to lower the cost of biodiesel. There are four primary ways to make biodiesel, direct use and blending, microemulsions, thermal cracking (pyrolysis) and transesterification. The most commonly used method is transesterification of vegetable oils and animal fats. The transesterification reaction is affected by molar ratio of glycerides to alcohol, catalysts, reaction temperature, reaction time and free fatty acids and water content of oils or fats. The mechanism and kinetics of the transesterification show how the reaction occurs and progresses. The processes of transesterification and its downstream operations are also addressed.
Efforts are under way in many countries, including India, to search for suitable alternative diesel fuels that are environment friendly. The need to search for these fuels arises mainly from the standpoint of preserving the global environment and the concern about long-term supplies of conventional hydrocarbon-based diesel fuels. Among the different possible sources, diesel fuels derived from triglycerides (vegetable oils/animal fats) present a promising alternative to substitute diesel fuels. Although triglycerides can fuel diesel engines, their high viscosities, low volatilities and poor cold flow properties have led to the investigation of various derivatives. Fatty acid methyl esters, known as biodiesel, derived from triglycerides by transesterification with methanol have received the most attention. The main advantages of using biodiesel are its renewability, better-quality exhaust gas emissions, its biodegradability and given that all the organic carbon present is photosynthetic in origin, it does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the greenhouse effect.
Vegetable oil fuels have not been acceptable because they were more expensive than petroleum fuels. With recent increases in petroleum prices and uncertainties concerning petroleum availability, there is renewed interest in vegetable oil fuels for Diesel engines. Dilution of oils with solvents and microemulsions of vegetable oils lowers the viscosity, but some engine performance problems still exist. The purpose of the transesterification process is to lower the viscosity of the oil. Pyrolysis produces more biogasoline than biodiesel fuel. Soap pyrolysis products of vegetable oils can be used as alternative Diesel engine fuel. Methyl and ethyl esters of vegetable oils have several outstanding advantages among other new renewable and clean engine fuel alternatives. The main factors affecting transesterification are the molar ratio of glycerides to alcohol, catalyst, reaction temperature and pressure, reaction time and the contents of free fatty acids and water in oils. The commonly accepted molar ratios of alcohol to glycerides are 6:1–30:1.
In this work the transformation process of sunflower oil in order to obtain biodiesel by means of transesterification was studied. Taguchi's methodology was chosen for the optimisation of the most important variables (temperature conditions, reactants proportion and methods of purification), with the purpose of obtaining a high quality biodiesel that fulfils the European pre-legislation with the maximum process yield. Finally, sunflower methyl esters were characterised to test their properties as fuels in diesel engines, such as viscosity, flash point, cold filter plugging point and acid value. Results showed that biodiesel obtained under the optimum conditions is an excellent substitute for fossil fuels.
A study was undertaken to examine the effect of temperature, moisture and storage time on the accumulation of free fatty acid in the rice bran. Rice bran stored at room temperature showed that most triacylglyceride was hydrolyzed and free fatty acid (FFA) content was raised up to 76% in six months. A two-step acid-catalyzed methanolysis process was employed for the efficient conversion of rice bran oil into fatty acid methyl ester (FAME). The first step was carried out at 60 degrees C. Depending on the initial FFA content of oil, 55-90% FAME content in the reaction product was obtained. More than 98% FFA and less than 35% of TG were reacted in 2 h. The organic phase of the first step reaction product was used as the substrate for a second acid-catalyzed methanolysis at 100 degrees C. By this two-step methanolysis reaction, more than 98% FAME in the product can be obtained in less than 8 h. Distillation of reaction product gave 99.8% FAME (biodiesel) with recovery of more than 96%. The residue contains enriched nutraceuticals such as gamma-oryzanol (16-18%), mixture of phytosterol, tocol and steryl ester (19-21%).
Studies were carried out on transesterification of Karanja oil with methanol for the production of biodiesel. The reaction parameters such as catalyst concentration, alcohol/oil molar ratio, temperature, and rate of mixing were optimized for production of Karanja oil methyl ester (KOME). The fatty acid methyl esters content in the reaction mixture were quantified by HPLC and H-1 NMR method. The yield of methyl esters from Karanja oil under the optimal condition was 97-98%. (c) 2005 Elsevier Ltd. All rights reserved.
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Processing and utilization of rice bran in United States
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