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The direct carbon fuel cell (DCFC) is an emerging technology for energy production. The application of biomass in DCFCs will be a major transition from the use of coal to generate energy. However, the relationship between biomass or biochar composition and the electrochemical performance of a DCFC is yet to be studied. The performance of a DCFC usi...
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... similar trend was reported for the biochar production using corn straw pellets [1]. The results in Table 1 also show that different types of biomass generate a different biochar yield. The proximate analysis and weight loss of the biochar generated from different biomass sources are represented in Table 2 and Figure 1, respectively. ...Similar publications
Direct carbon fuel cell (DCFC) is an emerging technology for energy production. The application of biomass in DCFC will be a major transition from the use of coals to generate energy. However, the relationship between biomass or biochar composition and electrochemical performance of DCFC is yet to be studied. The performance of DCFC by using carbon...
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... Physical activation is achieved by subjecting biosorbents to high-temperature gases, such as steam, CO 2 , or a combination of air and oxygen, between 700 and 900 • C (Palniandy et al., 2019;Yang et al., 2021). In the gasification process, carbon is removed from the biosorbents, resulting in the formation of pores and an increase in surface area. ...
... The proximate analysis of RHC and CRC in this study was compared with the findings of Palniandy et al. [37] (Table 3). The results indicated similarities in MC, AC, and FC. ...
Agricultural waste biomass is one of the most abundant and readily available sources of solid biofuel production. However, to ensure sustainability, it is crucial that the obtained biofuel is energetically efficient. In this study, briquettes were produced from rice husk char (RHC) and crushed rubberwood charcoal (CRC) separately and in combination. RHC and CRC briquettes were respectively labeled RHC10 and RHC0. Mixed biomass briquettes were produced at RHC–CRC mass ratios of 2:8 (RHC2), 4:6 (RHC4), 6:4 (RHC6), and 8:2 (RHC8). The combustion properties of the various briquettes were evaluated to determine potential enhancements, and the economic feasibility of production was evaluated. The addition of CRC enhanced the combustion properties of RHC, reducing ash content and increasing fixed carbon. The heating values of the mixed biomass briquettes were higher than the heating value of the RHC briquette. The RHC0, RHC2, and RHC4 briquettes had heating values exceeding 5000 cal/g, meeting the national standards for charcoal briquettes. However, the economic feasibility study revealed that only RHC0 and RHC2 briquettes had a payback period of less than four years, with a positive net present value (NPV) and an internal rate of return (IRR) exceeding a bank interest rate of 7%. Therefore, RHC0 and RHC2 briquettes could be suitable and environmentally friendly alternative energy sources with favorable combustion properties.
Graphical abstract
... Rice husk is the outer layer of the rice grain, accounting for 20% of the whole grain weight, which is widely generated during the milling process [1]. This residual biomass is often used as fuel in boilers and gasifiers for energy production [2][3][4]. On the other hand, residual biomass like rice husks is also utilized as raw material for adsorbent materials involved in wastewater treatment [5,6]. ...
Hydrothermal carbonization (HTC) of rice husk was optimized in terms of the adsorption capacity at equilibrium (qe) and hydrochar mass yield (MY). The studied variables were reaction temperature, residence time, and biomass-to-water ratio by means of response surface methodology. In both cases, reaction temperature resulted the most significant parameter promoting high qe values at higher temperatures when treating methylene blue (MB) as the target pollutant. Nevertheless, MY was low (~40%) when focusing on a possible industrial application. Hence, maximizing qe and MY simultaneously by optimization of multiple responses emerges as a promising solution to improve MY values (>60%) with no significant differences regarding the qe response. Furthermore, additional activation was conducted on optimal hydrochars to further investigate the enhancement of qe. As a result, no statistical differences between non-modified and activated hydrochars were observed for qe; however, the pseudo-second-order constant (k2) seemed to be increased after alkali activation, mainly due to a larger surface area. Non-modified and activated hydrochars were characterized via SEM, FTIR, XRD, and BET, resulting in two significant effects contributing to MB adsorption: increased surface area and functionalized hydrochar surface. Consequently, this work provides valuable insights on subsequent application of this HTC optimization scheme at an industrial scale.
... This finding is consistent with a previous study by Suman et al., who discovered that as temperature increased, the ash content of coconut husk biochar decreased [28]. Furthermore, Palniandy et al. [29] found that the ash content of rubber wood biochar decreased with increasing temperature, possibly as a result of some inorganic materials vaporizing into gas or liquid. The percentage of volatile matter and moisture content of the biochar significantly decreased with longer air intake and holding times, while the amount of fixed carbon increased. ...
The enormous coconut shell waste from local farmers and manufacturers has caused negative environmental and economic impacts in Thailand. A low-cost, small-scale pyrolysis kiln comprised of a cylindrical tank, gas circulating pipes, a kiln stand, and a manual drum lever was constructed and used to produce biochar from coconut shells in this study. The air intake and holding times for the biochar production process were varied. The biochar yield was 30.67% to 36.22%, or 4.6 kg to 5.4 kg per day per unit. The biochar porosity and fixed carbon content increased as the air intake and holding times were increased. The BET surface areas were 7.54 m²∙g-1 to 63.17 m²∙g-1. The pH values of biochar were alkaline, in the range of 7.34 to 10.24. Therefore, biochar can be used as a soil amendment material. The Net Present Value (NPV), the Internal Rate of Return (IRR), and the payback period are 52,757 THB (1,459.79 USD), 18.71%, 4 years, 10 months, and 27 days, respectively. According to economic analysis, investing in coconut shell biochar production under optimal conditions using the developed kiln is acceptable and can be viewed as a potential approach to providing additional economic benefits for coconut-based enterprises and the Thai community.
... Biochar characteristics such as the concentration of acidic functionalities (particularly the phenolic species), the degree of aromatic condensation, and the pore volume can be tailored by infiltrating the biomass with suitable iron salts and clay minerals before pyrolysis (Rawal et al., 2016). There are several studies about the post-treatment of biochar (Xiang et al., 2020;Palniandy et al., 2019), often with similar additions as discussed earlier for pre-treatment. These studies show that post-treatment with steam, air, or chemical methods alters biochar properties like pH, organic C, adsorption capacity, specific surface area, porosity or ash content (Klasson et al., 2014). ...
Interactive climate factors, the industrial revolution, excessive fertilizer use, pesticides, wastewater use in agriculture, landfill leachates, and mine tailings cause land degradation and reduce crop production worldwide. Biochar can mitigate global climate change, reduce soil degradation, drought, and waterlogging effects, and increase crop production. It can also reduce the bioavailability and phytotoxicity of pollutants in contaminated soils via the mobilization of inorganic and/or organic contaminants, commonly through surface complexation, electrostatic attraction, ion exchange, and co-precipitation. When biochar is applied to soil, it typically neutralizes soil acidity and enhances soil aeration, water holding capacity, cation exchange capacity, and microbial activity, and therefore, it was employed to ameliorate crop abiotic/biotic stress. This review discusses the association of biochar with poor soil condition (salinity, drought, flooding and heavy metal stress) and their interactive effect to improve plant physiological performance and biomass production. Biochar applied with other stimulants like compost, humic acid, phytohormones, microbes and nanoparticles can surprisingly enhance plant farming, cultivation practices and plant eco-physiological responses in saline, waterlogged and dried areas with economic sustainability. Overall, biochar can provide an exciting and promising component, especially in nutrient-poor degraded soils for the improvement of plant cultivation and crop production worldwide taking it a step closer to successful commercialization.
... Reduction of moisture content, OM combustion, and mineral content of the samples could result in the variation of FTIR spectra [28]. This might have happened as a result of aromatic hydrocarbons in biochar breaking and reforming [29]. The broad bands at 3318.38 cm -1 (rice hull feedstock), 3309.64 cm -1 (banana peel feedstock), 3334.90 cm -1 (sawdust feedstock), 3637.74 cm -1 (RHB-500), 3119.64 cm -1 (BPB-550) and 3336.78 ...
The emission of hydrogen sulfide (H2S) from municipal solid waste is one of the environmental issues that raised the public's attention and awareness. Exposure to H2S that brings a foul smell of rotten eggs will cause headaches, irritation, dizziness, fatigue, and even death if the concentration of H2S is too high. The study's goals are to investigate the properties of biochars made from rice hulls, banana peels, and sawdust; to compare the biochars' physical and chemical properties; and establish the H2S removal efficiency of the three biochars. Biochars derived from rice hull (RHB-500), banana peel (BPB-550), and sawdust (SDB-500) by pyrolysis were used as the adsorbents. The biochar yield, pH, ash content, surface functional group, and morphology of the biochars produced were investigated. In this study, H2S was synthesized by mixing food waste and soil in the experimental column. The H2S produced was reduced by the adsorption method. The removal efficiencies of H2S for each biochar were determined by allowing the synthetic H2S to flow through the two columns that were packed with sand (act as control) and biochars, respectively. All biochars were alkaline, and BPB-550 had the highest pH, followed by SDB-500 and finally RHB-500. The order for removal efficiency of H2S (>94%) is BPB-550 > SDB-500 > RHB-500. Overall, the biochars derived from biomass had a strong ability to act as the adsorbents for H2S removal.
... Figure 3 show that the FT-IR spectra of CSBC were somewhat different from those of RHB. In particular, the FT-IR spectra of RHB in this study were similar to other high-temperature biochar derived from rice husk [48,49], which possess several types of functional groups, including O-H (3437 cm −1 ),-COOH (1606 cm −1 ), C-H aliphatic (1369 cm −1 ), C-O-C (1103 cm −1 ) and Si-O (465 cm −1 ) groups [50]. Meanwhile, characteristic bands for CSBC were observed in the infrared spectrum around 3849 cm −1 and 3423 cm −1 , attributed to amine N-H symmetrical vibration and an H-bonded O-H group. ...
In this study, shrimp shell-derived chitosan (CS) and rice husk-derived biochar (RHB) were produced; CS and RHB were then used to synthesize chitosan-modified biochar (CSBC) hydrogel beads. N2 adsorption (77K), SEM-EDX and FT-IR techniques were used to evaluate the physicochemical properties of the adsorbents. A batch experiment was conducted to test the methyl orange (MO) adsorption performance of RHB and CSBC. The results showed that the MO adsorption process was strongly pH-dependent. The kinetics were well described by the pseudo-second-order and intra-particle diffusion models, assuming the chemisorption and intraparticle diffusion mechanisms govern the adsorption process. Homogeneous adsorption for MO on the surface of RHB and CSBC was also assumed since the isotherm data showed the best-fit to the Langmuir model. Under the experimental conditions of initial pH 3, dosage 0.2 g, contact time 240 min and temperature 298K, the maximum adsorption capacity of CSBC and RHB for MO dye adsorption was 38.75 mg.g−1 and 31.63 mg.g−1, respectively. This result demonstrated that biochar had better performance after modification with chitosan, which provided more functional groups (i.e., −NH2 and −OH groups) for enhanced electrostatic interactions and complexation between MO and CSBC. Overall, CSBC is an effective adsorbent for the removal of MO from aqueous solution.
... The type and structure of carbon fuel affects the performance of DCFC significantly [8]. As an example, woody biochar generally produced higher maximum power density compared to non-woody biochar [9]. A high fixed carbon content in the biochar is desired for higher fuel value Abstract: Direct carbon fuel cell (DCFC) with higher power efficiency and lesser emissions is being viewed as a potential clean energy source. ...
... The intensity of this peak does not differ much, in good agreement with the reported moisture content via proximate analysis in Table 2. The peak exists between 2700 cm -1 to 3000 cm -1 indicates the presence of aliphatic C-H stretching in all biochar samples [9]. Besides that, a new peak was formed at the range of 2400 cm -1 to 2000 cm -1 when the black liquor-extracted compound undergoes pyrolysis. ...
... Therefore, the performance of biochar pyrolyzed at higher temperature might be negatively impacting DCFC performance due to the reduction in the surface oxygen functional group. In addition, as the temperature goes higher, broad peaks with increasing intensity was formed at 1056-1090 cm -1 (Si-O-Si) and 780 cm -1 (Si-H), indicating the presence of silica in the biochar [9]. The high ash content reported in proximate analysis might be contributed by high silica content in the raw material as the black liquor is originated from rice straw. ...
Direct carbon fuel cell (DCFC) with higher power efficiency and lesser emissions is being viewed as a potential clean energy source. The application of renewable biochar as fuel for DCFC is found to be feasible to replace coal or carbon black for power generation. Black liquor from the paper production might be a suitable fuel source for DCFC due to its high lignin or carbon content. In this study, the feasibility of using compound extracted from black liquor as fuel source for DCFC was investigated in the aspect of physico-chemical and electrochemical properties. Suitable pyrolysis temperature in producing biochar from black liquor compound was first investigated. Results have shown that fixed carbon and ash content increased slightly with increasing pyrolysis temperature. The ash content is made up of majority of silica as depicted in FESEM-EDX results. Oxygen containing functional group was decomposed under high pyrolysis temperature of 700°C and 800°C. Besides, biochar obtained at 500°C of pyrolysis temperature has given the highest power density of 1.22 mW cm-2 whereas 1.44 mW cm-2 was obtained from coal which was used as the control. Future work on ash removal from the black liquor prior to pyrolysis might improve the potential of black liquor derived compound as a fuel source for DCFC.
... The important peak at 1095 cm −1 was showed of stretching vibration of Si-O-Si bond of silica functional group [48,49]. For CA, the major peaks were observed at 3420 cm −1 , 2920 cm −1 , 1600 and 1420 cm −1 , 1080 and 1030 cm −1 corresponding to the stretching of -OH, C-H, COO-, C-F groups, respectively [50][51][52]. ...
... The characteristic of stretching vibrations of -OH groups because of the phenolic groups shows a broad peak at 3420 cm −1 in FTIR spectrum [52]. The visible peak at 2920 cm −1 represents the C-H stretching vibration from glucose [48] while the bands between at 1600 and 1420 cm −1 correspond to open-chain imino and COO -groups, respectively, [50]. The peak at 1080 cm −1 corresponds to the symmetric stretching vibration of Si-O-Si. ...
... The isotherm models are used to fit the experimental adsorption data to evaluate the distribution of metal ions among the liquid phase (adsorbate) and the solid phase (adsorbent) at equilibrium to understand the adsorption mechanism and identify the maximum adsorption capacity (Table 1) [18,24,25,27,50]. The heavy metal ions are adsorbed on the adsorbent surface with chemical or physical interactions at equilibrium. ...
Groundnut biochar (GHB) encapsulated in calcium-alginate (CA) beads (GHB-CA) was synthesized as a novel composite adsorbent for the removal of copper (II) and zinc (II) from an aqueous solution. BET, SEM, EDS, FTIR, TGA were used to characterize the adsorbents. The data obtained were used to establish the adsorption isotherm using the models of two-, three- and four-parameter isotherms. To study the kinetics of adsorption of heavy metals adsorption on CA and GHB-CA, the pseudo-first-order model, the pseudo-second-order model, Esquivel, Avrami and Bangham were used. The adsorption performance showed that they could use low-cost and effective alginate-based composites for heavy metal removal. To obtain maximum adsorption, applied a full factorial design of three factors (metal ion type, adsorbent type and adsorbent dose) at two levels. It statistically optimized the influence of main variables on copper and lead removal using the synthesized novel adsorbent.
... And that the higher the moisture content, the poorer its performance in the removal of nutrients, and the reverse. The application of biochar derived from rice husk and rubber wood biochar was studied by Palniandy et al., (2019). The finding suggested that the high moisture content level of rice husk biochar could be owing to biochar's hygroscopic nature after pyrolysis, which allows it to absorb moisture from the environment. ...
Enrichment of water bodies with nutrients from wastewater is one of the causes of eutrophication to aquatic ecosystems. This study investigated the use of biochar derived from rice husk, coconut husk, and coffee husk in adsorbing nitrates (NO3-N) and nitrites (NO2-N) from slaughterhouse wastewater. It also explored the desorption efficiencies of the adsorbed nutrients to ascertain the applicability of the enriched biochars as slow-release fertilizers. To characterize the physicochemical properties of the biochars, scanning electron microscopy (SEM) was used. Fourier transforms infrared spectroscopy (FTIR), elemental analysis (CHNO) Langmuir and Freundlich, and the isotherm models were employed to fit the experimental equilibrium adsorption data. It was observed that the Langmuir isotherm model has the best fit of NO3- N and NO2- N on all the biochars. And this was based on the coefficient of correlation values. Also, the coconut husk biochar has the highest adsorption capacities of NO3-N and NO2-N at 12.97mg/g, and 0.244 mg/g, respectively, attributing to its high porosity as revealed by the SEM images. The adsorption capacities for the rice husk char were12.315 and 0.233 mg/g, while that for coffee husk char were12.08mg/g and 0.218 mg/g for NO3-N and NO2-N, respectively. The relatively higher amount of NO3-N adsorbed to that of NO2-N could be attributed to its higher initial concentration in the solution than nitrite concentration. The desorption efficiencies of nitrates were 22.4, 24.39, and 16.79 %, for rice husk char, coconut husk char and coffee husk char, respectively. For the rice husk char, coconut husk char and coffee husk char, the nitrites desorption efficiencies were 80.73, 91.39, and 83.62 %, respectively. These values are good indicators that the studied biochar can be enriched with NO3- N and NO2- N and used as slow-release fertilizers.
