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Maintaining a temperature level of about 40°C, the optimum temperature for mesophilic bacteria’s growth and activity, is crucial for obtaining the best results with respect to biogas production. This study investigates the utilization of solar energy for heating a bioreactor that was already developed at our laboratory and is currently in operation...
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The aim of this research was to enhance the performance of the anaerobic digestion of livestock manure in plug-flow biogas digesters. Experiments were conducted to investigate the effects of passive solar collector and diurnal temperature variation on the performance parameters of a biogas digester. Two identical digesters were designed and manufac...
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... The three primary areas of focus, globally and at various levels such as regional and local (in the case of Jordan), are energy, ecology, and economy [1]. Biomass generation has been considered as a potential source of environment pollution at national and global scale [2]. ...
This study aims to assess the viability of utilizing poultry manure for biogas production as a means of contributing to the electricity grid and reducing environmental pollution in Jordan. A system consisting of a bioreactor, heating source, biogas collection device, and a subsystem for evaluating the ratio of biomethane to biogas is designed and fabricated. The system operates under mesophilic temperature settings, with a pH of 7, and a carbon-to-nitrogen ratio of 25 to 1. The modified Gompertz system is employed to simulate the experimental results.
The findings demonstrate that poultry manure has the capacity to generate around 2.032 × 10 ³ cubic meters of biogas per year, which is equivalent to 1.32 × 10 ⁹ kilowatt-hours or 4.75 × 10 ¹² kilojoules. These numbers account for 7.8% of Jordan’s energy sector and result in an 18% reduction in biowaste, equivalent to 1.08 million tons. Furthermore, the experimental results coincide completely with the modified Gompertz model. These findings indicate that utilizing poultry manure for biogas production has the potential to contribute to the electricity grid in Jordan and reduce environmental pollution caused by biomass.
... The study develops the field of hybridization of solar energy with anaerobic digestion by focusing on a critical and less explored aspect: harnessing solar energy generated by hybrid collectors to meet the energy (electrical and thermal) demand of the digester up to the stage of biomethane generation. Previous studies in this field have mainly focused on the thermal demand, using solar water heaters for temperature exchange or greenhouses [15,16,23]. Other proposals include hybrid polygeneration energy systems in rural communities involving micro-grids and multiple energy sources [20,21]. ...
... Therefore, the integration of other renewable energy systems for auxiliary heating becomes necessary [13][14][15]. Alkhamis et al. [16] coupled solar energy with biogas reactors to provide the necessary heat for biogas production, achieving an internal rate of return (IRR) of 32.7% on the investment in the solar system. Tiwari et al. [17] conducted research on photovoltaic thermal integration systems for biogas heating, demonstrating that the addition of solar energy increased biogas production. ...
Biogas heating plays a crucial role in the transition to clean energy and the mitigation of agricultural pollution. To address the issue of low biogas production during winter, the implementation of a multi-energy complementary system has become essential for ensuring heating stability. To guarantee the economy, stability, and energy-saving operation of the heating system, this study proposes coupling biogas and solar energy with a phase-change energy-storage heating system. The mathematical model of the heating system was developed, taking an office building in Xilin Hot, Inner Mongolia (43.96000° N, 116.03000° E) as a case study. Additionally, the Sparrow Search Algorithm (SSA) was employed to determine equipment selection and optimize the dynamic operation strategy, considering the minimum cost and the balance between the supply and demand of the building load. The operating economy was evaluated using metrics such as payback period, load ratio, and daily rate of return. The results demonstrate that the multi-energy complementary heating system, with a balanced supply and demand, yields significant economic benefits compared to the central heating system, with a payback period of 4.15 years and a daily return rate of 32.97% under the most unfavorable working conditions. Moreover, the development of a daily optimization strategy holds practical engineering significance, and the optimal scheduling of the multi-energy complementary system, with a balance of supply and demand, is realized.
... If the temperature is below 15 °C in anaerobic digestion biogas production become insignificant. This problem can be overcome by using solar energy to support a biogas reactor or plant (Alkhamis et al., 2000;Chamoli et al., 2011) or by using electricity or heat from grid. Heat in biogas digester is required in three aspects: 1) the heat required to raise feedstock temperature; 2) to compensate for heat losses within the digester; 3) to compensate for losses that could occur in the pipelines between the heat source and the bioreactor. ...
Paper discusses using a low-temperature biogas reactor with a solar support system technology as a management tool of biodegradable waste in small scale. A feasibility study looks at primary factors affecting anaerobic digestion process and solar heat production, design examination of a solar heating for anaerobic digester and possible technology application, also defines the multilocality of biogas, illustrates diffusion of innovation for diversification of biogas production. Analysis confirms solar heat increases efficiency and production of biogas, decreases costs and toxicity of digestate. Results show that for implementation of technology in rural areas further research in socioeconomic , sourcing of feedstock and customization is needed.
... Furthermore, the system is covered with movable insulation to prevent heat loss at night from both the top and sides of the dome. Alkhamis et al., [41] integrated a solar collector into a bioreactor system and investigated the ability of the system to maintain a constant temperature of 40 • C. A solar collector combined with a heat exchanger could meet heating requirements for a water jacket around a bioreactor at higher than 60% efficiency. Cost analysis revealed that the internal rate of return for the investment in this solar heating system was approximately 32.6%, indicating the system's high cost-effectiveness. ...
Decarbonisation of the production and utilisation of natural gas (NG) is the main force behind attempts to reach climate targets because NG is one of the most dominant fuels in the energy and transportation sectors. In the transition to a carbon-neutral society, steps must be defined towards achieving cleaner production and utilisation of NG and towards post-combustion carbon capture to create a completely closed carbon cycle. Methane produced using renewable energy sources is a sustainable substitute for NG and is crucial to accelerating the penetration of the current energy infrastructure by renewables. Supported by existing gas transportation networks, renewable methane (RM) is both an energy storage medium and an advanced fuel that can be used in areas that are considered difficult to electrify. The present article is a state-of-the-art review of RM and a range of clean technologies from production to end-use and carbon capture, which are necessary to minimise lifecycle carbon emissions. The techno-economics and challenges of replacing NG with RM are emphasised. The focal research points for a future RM economy with respect to systems design are highlighted, and the novel renewable-powered technologies that are required to promote net-zero emissions are summarised. Although employing RM is not economically feasible, trends towards carbon emission limitations, carbon taxes, and renewables subsidies will make RM cost-competitive with NG. In view of the state-of-the-art technologies, future research is expected to develop energy- and cost-effective production and utilisation solutions for enhancing the feasibility of RM.
... The hybrid solar biogas system shows an excellent outcome of nearly 61% efficient than the conventional techniques due to better usage of controller. The behavior of controller is more effective and its rapid outcomes was sensed for minimum variations in the water temperature (Alkhamis et al., 2000). In general the temperature fluctuation occurs due to variation in sun radiations. ...
Anaerobic Digestion (AD) is one of the promising wastestoenergy (WtE) technologies that convert organic wastes to useful gaseous fuel (biogas). In this process methane is produced in the presence of methanogens (bacteria). The survival and activities of methanogens are based on several parameters such as pH, temperature, organic loading rate, types of biodigester. Moreover, these parameters influence the production of biogas in terms of yield and composition. Maintaining an appropriate temperaturefor AD is highly critical and energy intensive. This study reviews the various hybrid technologies assistedbio gas production schemes particularly from renewable energy sources. Also discuss the direct and indirect solar assisted bio-digester impacts and recommendation to improve its performance. In addition, the performance analysis Solar Photovoltaic(PV) and thermal collector assisted bio gas plants; besides their impact on the performance of anaerobic digesters. Since opportunities of solar energy are attractive, the effective utilization of the same is selected for the discussion. Besides, the various constraints that affect the yield and composition of biogas are also evaluated along with the current biogas technologies and the biodigesters. The environmental benefits, challenges and socio-economic factors are also discussed for the successful implementation of various technologies.
... The temperature of the digester was increased by 3 ºC with a corresponding increase in biogas production by 7-15%, when the top of the digester was coated with charcoal but, the main disadvantage with this method was to repeat the coating once every one and half month (Anand and Singh, 1993) [4] . Alkhamis et al. (2000) [3] used water jacket around the digester to circulate hot water from the solar based heating device and results revealed that digester temperature of 40 ºC was achieved in one hour by circulating hot water through water jacket. During colder months of the year, the use of two solar green houses, one surrounding the digester and the other inner greenhouse to heat the contents of the digester improved the digester temperature by 9.8 ºC than the ambient temperature which supported the biogas production throughout the year (Hassanein et al., 2015) [13] . ...
... The temperature of the digester was increased by 3 ºC with a corresponding increase in biogas production by 7-15%, when the top of the digester was coated with charcoal but, the main disadvantage with this method was to repeat the coating once every one and half month (Anand and Singh, 1993) [4] . Alkhamis et al. (2000) [3] used water jacket around the digester to circulate hot water from the solar based heating device and results revealed that digester temperature of 40 ºC was achieved in one hour by circulating hot water through water jacket. During colder months of the year, the use of two solar green houses, one surrounding the digester and the other inner greenhouse to heat the contents of the digester improved the digester temperature by 9.8 ºC than the ambient temperature which supported the biogas production throughout the year (Hassanein et al., 2015) [13] . ...
In high altitude areas, great variation in the ambient temperature throughout the year affects biogas production. During cold seasons there is either reduction or complete cessation of biogas production. In order to maintain optimum biogas production throughout the year, it is necessary to protect the digesters from cold shock. Thus, the study was carried out to determine the effects of digester temperature on biogas production during summer and winter season. While during monsoon season, the digesters were heated by circulating hot water produced by solar water heater through water jacket which improved the digester temperature to 37.76±0.36 ºC in single stage (D1) and 36.25±0.31 ºC in two stage digester (D2), when the mean ambient temperature was 22.18±0.164 ºC. This effect increased the biogas production to 2.51±0.04 and 2.95±0.09 m 3 /d. With the increased digester temperature, the composition of biogas improved. Methane concentration increased by 10.22% than in the winter and 6.45% than in the summer season in D1. While in D2, the increase was 13.24% greater than in winter and 8.93% greater than in summer season. Thus, heating of digesters prevented heat loss and improved the quality and quantity of biogas. 1. Introduction The world is on a paradigm shift towards renewable sources of energy to reduce the effects of global warming and climate change due to fossil fuels. The common renewable sources of energy include solar energy, wind energy, hydro energy and bioenergy. Anaerobic digestion (AD) is one form of bioenergy by which, biogas can be obtained from biomass. The breakdown of complex organic matter to simpler ones with the production of gas rich in methane, by a group of anaerobic bacteria and archaea in oxygen free environment not only helps to recover energy from biomass but also controls pollution by efficient disposal of organic waste and reduced Green House Gas emission (Abdelgadir et al., 2014) [1]. Several factors like substrate composition, digester design and operating parameters affect the biogas production with temperature being the prime one (Cioabla et al., 2012) [6]. The digestion process occurs in three different temperature ranges, viz., psychrophilic (0-20 ºC), mesophilic (20-42 ºC) and thermophilic (42-75 ºC), and the rate of degradation of the substrate will be reduced when the temperature falls below 15 ºC (Rajeshwari et al., 2000) [19]. But usually, mesophilic and thermophilic temperature ranges are preferred because, higher temperatures increases the rate of degradation of organic matter with improved organic loading rate (OLR) and lowered hydraulic retention time (HRT) along with the destruction of pathogens from the raw materials (Kocar and Eryasar, 2007) [16]. The growth of the methanogenic bacteria is higher at thermophilic range while, that of the acidogenic bacteria at mesophilic range. The sudden fluctuation in the temperature negatively affects the fermentation process of biogas production. As such variations causes microbial imbalance in the digester, the consortia may take a minimum time of three weeks to adapt to the new environmental condition (Adekunle and Okolie, 2015) [2]. The digesters operated at thermophilic temperature range are highly sensitive to the temperature fluctuations and may tolerate a variation of about only +/-1 ºC while, the mesophilic digesters tolerates a fluctuations of +/-3 ºC (Weiland, 2010, Dobre et al., 2014) [21, 9]. During the colder months, the lower ambient temperature lowers the digester temperature which decreases the biogas production (Ferrer et al., 2011, Divya et al., 2014) [10, 8]. In order to maintain optimum temperature within the digester and to prevent heat loss through the
... Energy, in its many useful forms, is an essential need for our daily lives as it directly impacts our standard of living and technological progress [1]. Bioenergy has become more popular in recent decades as biotechnology has advanced [2]. Bioenergy offers a sustainable waste solution since organic waste components can be used as biomass for urban and agricultural byproducts. ...
... As a result, biogas producers have taken the opportunity to use solar energy to thermally absorb heat in the reactors. In India, China, Thailand, and Jordan, successful tests were carried out in which the systems effectively maintained the required reactor temperatures [2][3][4]. ...
Biogas as an energy source is increasing its popularity in both small and large-scale applications. The anaerobic digestion (AD) process requires heat to produce biogas effectively, which can be supplied via a solar system. The suitability of integration of solar thermal energy in anaerobic digestion was researched through this paper. With the help of TRNSYS software, a 0.2 m 3 simulation model of the digestor reactor along with a 2m 2 PV solar thermal system was built. A study was done in an atmospheric condition of Rockhampton in Central Queensland based on the thermal activity and dynamic behaviour of the structure. Cow manure was used as a feedstock in the system. The simulation was run for predicting the daily average temperature within the AD of a typical month in summer and winter. The simulation was also done for predicting the biogas production in typical summer and winter months, and for all seasons in Australia. The simulated temperature was found to be the temperature of the biogas production at a mesophilic temperature of about 35°C. The result showed that the maximum predicted temperature was found to be 35.98 °C in the summertime and 35°C in wintertime. The result also showed that the maximum biogas production is 84.45L/day in summertime and 72.33 L/day in wintertime. So, the solar heating system can help increase the bio-digester temperature which contributes to the production of biogas in the AD system. Thus, the developed model can be considered as an accurate tool to predict biogas production in Central Queensland (Rockhampton) climate for solar assisted AD systems. It is expected that the simulation model can be extended to predict biogas production from solar-assisted AD systems in other climatic conditions.
... To indicate the gap between some literature and this present study, the following presentation showed various studies in this field. Several investigators have suggested that solar energy could be combined to heat biogas digester unite throughout the winter season (Al Khamis et al., 2000;El-Mashad et al., 2004;Kocar and Eryasar, 2007;Chen and Qin, 2014;Ali, 2015;Maji, 2015). Feng et al. (2016a) used thermostatic system for heating biogas digester unite and indicated only the biogas production, they were able to clarify the consumed heat, but they do not determine the contribution of solar energy to the production process. ...
The main drawback of heating biogas digestion systems based on solar energy is its unavailability overnight and at different times (days and months). To circumvent this problem, a hybrid system(solar and electricity) powering the heat digester could provide the required mesophilic conditions. The present study aimed to evaluate the technical and design feasibility of using solar energy to assist in heating the digestion units. Also, measured and determined the contribution of solar energy to heat the system. This study was conducted in the central area of Coastal Delta, Egypt (30.5∘N, 30.6∘E; 8.5 m a.s.l.). Results show that the contribution of solar energy to biogas production was 75.21%, 60%, and 53.58% when using three settings temperature of (37, 40, and 45 °C) of the energy consumed via cattle dung solution heating. Furthermore, increasing the set temperature inside the horizontal and vertical digesters from 37 °C to 45 °C augmented their daily average volumetric biogas production by 87.12% and 59.45%, respectively. Finally, the current study says that solar energy has reduced energy consumption by 61.28%. Also, the economic analysis indicates that the estimated return profit was $ 177.41 (USD), which represents 45.15% of the total income per operation.
... However, the beneficial effect of increased temperature on improved protein content can be associated with greater enzyme secretion by certain microbes [33,34]. Inoculated microbes enhanced the CP levels of both fermented TMR with CSM/RSM, and maintaining a steady temperature throughout fermentation was noted as necessary to keep the bacteria growing and active [35]. The optimal temperature for reducing the concentration of GL was 32 • C, indicating that this temperature is favorable for microbial growth in fermented TMR with rapeseed meal medium. ...
Cottonseed meal (CSM) and rapeseed meal (RSM) are protein sources in livestock feed. However, the applications of both ingredients are limited in diets due to the existence of anti-nutritional factors such as free gossypol and glucosinolate. The aim of this study was to determine the optimal fermentation conditions for reducing anti-nutritional factors and increasing the nutritional value of fermented total mixed rations containing cottonseed or rapeseed meal. An orthogonal design L9 (34) was performed to optimize the fermentation conditions, including fermentation time, temperature, moisture content and microbial strain. Optimum fermentation conditions were performed using different fermentation times (48, 60, 72 h), fermentation temperatures (28 °C, 32 °C, 36 °C), moisture content (40%, 50%, 60%) and microbial inoculations (1 = Bacillus clausii with 1 × 109 CFU/kg DM for CSM or 1 × 1010 CFU/kg DM for RSM; 2 = Saccharomyces cariocanus with 5 × 109 CFU/kg DM; 3 = mixed strain (B. clausii:S. cariocanus ratio 1:1). The results show that the concentration of free gossypol content was reduced (p < 0.05), while the crude protein content was increased (p < 0.05) in CSM through optimum fermentation conditions: time 60 h; temperature 32 °C; moisture content 50% and inoculated with B. clausii (1 × 109 CFU/kg DM) as well as S. cariocanus (5 × 109 CFU/kg DM). Likewise, the concentration of glucosinolate was lowered (p < 0.05) and the crude protein was increased (p < 0.05) in RSM through optimum fermentation conditions: time 60 h; temperature 28 °C; moisture 50% and inoculated with B. clausii (1 × 1010 CFU/kg DM) as well as S. cariocanus (5 × 109 CFU/kg DM). Our findings indicate that the optimal fermentation conditions of total mixed rations with cottonseed meal or rapeseed meal enhance the nutritional value, thereby making them viable and usable feedstuffs for potential use in livestock industries.
