Biomethane Production Research Articles

Evaluation of the electrical energy potential of biowaste with methane production kinetics and environmental impact for northeastern region of India

Developing and assessing sustainable energy systems have gained more attention in the circular economy and national growth context as the global energy crisis intends new initiatives. So, this paper aims to evaluate the electrical energy potential of bio-waste from livestock and poultry in the selected area of northeastern India using Waste to Energy (WtE) technology. The environmental impact assessment is also performed with Global Warming Potential (GWP), Acidification Potential (AP), and Dioxin Emission Potential (DEP). The kinetics of methane production are analyzed for two different seasons, summer and winter, by evaluating Bio-Methane Production (BMP). Further, the potential of electric energy and environmental impacts, including kinetics, are assessed. To achieve this, the livestock and poultry population is forecasted using a data-driven model, and the waste profile is estimated. In addition, an optimization algorithm is used to maximize methane production when kinetics are included. The obtained results are compared for cases without and with kinetics in methane production from livestock and poultry manure, and then validated with existing literature. Finally, this study examines the economic feasibility of bio-generation potential to meet the real-time load of the selected site. Accordingly, this work helps in the planning and designing of bioenergy power plants.

Insights on optimizing landfill site selection inspired by co-fermentation of weathered coal and landfill leachate

To develop new methods for transforming waste resources such as landfill leachate and weathered coal into clean energy, this research analyzed the co-fermentation effect and internal mechanism of methane production through gas chromatography, three-dimensional fluorescence, inducive coupling and metagenomics techniques. Our findings revealed that landfill leachate addition drives more than 70% increase in weathered coal biomethane production. Anaerobic fermentation collectively increased the tryptophan content in liquid-phase biodegradation, with the highest proportion reaching up to 72%. Paracoccus, Ralstonia, Aquamicrobium and other major microorganisms were in the range of 9–32%. Contamination of heavy metal diversity resistance genes has impacted microflora composition, with specialized heavy metal resistance genes such as NreB, CopD, NreB, and MerP altering the influence of heavy metals on anaerobic fermentation. The combined anaerobic fermentation of landfill leachate and weathered coal has expanded clean waste utilization and has broad application prospects.

Antioxidants and biomethane production from Opuntia varieties

In this study, Opuntia varieties were investigated for their potential to fit a biore-finery approach. This work proposed the extraction of antioxidants and the production of biomethane from their solid effluents. Three Opuntia varieties –O. ficus-indica var. Milpa Alta (OfiM), O. ficus-indica var. Copena (OfiC) and O. engelmannii (Oe)– were subjected to solvent extraction. Our results revealed that 80% methanol yielded the highest amount of phenolic compounds (8.99 mg/g) and flavonoids (1.67 mg/g) in OfiM. Subsequently, biomethane potential experiments compared raw and residual biomasses, as well as inoculum-to-substrate ratio (ISR, 0.5, 1.5 and 2.5). Biomethane yields were lower with residual biomass compared to raw Opuntia. The highest biomethane yield of 552 mL CH4/g VS was achieved with raw OfiM at ISR 2.5. For the second assay of OfiM, biomethane yields were 412 and 458 mL CH4/g VS, respectively for residual and raw biomasses. Despite a decrease of approximately 10% in biomethane yield due to extraction operation, the coupling of both processes becomes highly desirable to obtain high-value extractable compounds and substantial biomethane production, which is a step towards the Opuntia biorefinery.

Biomethane produced from maize grown on peat emits more CO2 than natural gas

Cultivation of maize for biomethane production has expanded rapidly, including on drained peat soils. The resulting soil CO2 emissions at the point of feedstock production are largely overlooked when assessing biogas climate mitigation potential. On the basis of field-scale flux measurements, we calculate that soil CO2 emissions from biomethane feedstock production on drained peat exceed embodied emissions for an equivalent amount of natural gas by up to a factor of three.

Optimization framework of clean heat and CO2 supply for agricultural greenhouses exploiting industrial symbiosis

The rising demand for greenhouse cultivation poses a challenge in providing environmentally friendly energy to maintain favorable greenhouse indoor conditions. This research presents an optimization model to identify cost-optimal symbiotic pathways to replace the import of three key greenhouse crops (tomato, cucumber, lettuce) with local greenhouse production. The proposed solutions involve greenhouses that can meet these crops' heat and CO2 demands via industrial symbiosis. Switzerland is investigated as the case study, and the (waste) heat suppliers are municipal solid waste incinerators, cement production plants and biogas plants. Upgrading biomethane production plants are also considered potential CO2 suppliers. The objective is to minimize the discounted cost when replacing 25%–100 % of vegetable imports with local agricultural greenhouses, considering availability of suitable land as well as waste heat and CO2 suppliers. Optimization results suggest prioritizing northeast and west Switzerland for greenhouse development, due to the availability of suitable land and proximity of waste heat and CO2 suppliers. Waste incinerators could provide 50%–70 % of the necessary heat, while Organic Rankine cycle in cement plants could generate 63 % of the electricity of supplementary lighting demand of greenhouses. While tailored for Switzerland, the optimization framework's general formulation can be adapted also to other regions to optimize greenhouses' heat and CO2 demands. The optimization code is provided open source for associated applications.

Efficient technology for food waste valorization: an integrated anaerobic digestion—microbial electrolysis cell for biomethane production

Efficient technology for food waste valorization: an integrated anaerobic digestion—microbial electrolysis cell for biomethane production

Biomethane production modelling from third-generation biomass

Third-generation biomass constitutes a renewable energy source that could substitute fossil fuels. This study evaluated the biomethane potential (BMP) of Ulva sp., Codium sp. and Undaria pinnatifida through anaerobic digestion. The daily production of biomethane was evaluated using different models, including Modified Gompertz, Chen and Hashimoto, First-order, Transfer and Cone models, as well as an Artificial Neural Network (ANN) model. The experimental BMP was 0.17, 0.26, and 0.32 Nm³/kg VS for Ulva sp., Codium sp., and U pinnatifida, respectively. Among the non-linear regression models, the Transfer model (R2 > 0.9915) and the First-order model (R2 > 0.9889) are the ones that best fit the experimental data. However, the ANN shows a better fit (R2 > 0.999 and RMSE<4.537) to the data compared to the non-linear regression models. Furthermore, ANN can capture the complexity of biological systems, allowing for more accurate and detailed modelling of the processes involved. The identification and optimization of the biomethane potential of macroalgae contribute to developing sustainable energy alternatives, offering a renewable energy source that could mitigate the environmental stress associated with traditional fossil fuels.

Modeling and manufacturing of solar modules of different designs for energy supply of biogas plant

The article presents a description of the modeling and manufacturing of solar modules of photovoltaic, thermal and photovoltaic thermal designs intended to supply energy to a biogas plant intended for the production of biohydrogen and biomethane. Mathematical modeling of the photovoltaic module was carried out and the calculated temperature of the photovoltaic converters was determined, and also the photovoltaic module was manufactured using the process of sealing the photovoltaic converters with a two-component polysiloxane compound. Mathematical modeling of a solar thermal collector with water radiators in the form of a round copper tube, an oval copper tube, as well as a rectangular water cooling channel (“water jacket”) was also carried out, in which pressure losses and the amount of water heating were assessed. The distances between the rectangular channels of the water-cooling radiator for uniform heat removal were determined, and mathematical modeling of the thermal state of a solar thermal collector with a semicircular cross-section of the water-cooling radiator channel was carried out, after which the solar thermal collector was manufactured. Mathematical modeling of the total displacements of the components of a photovoltaic thermal module, the values of which do not exceed acceptable limits, was carried out, after which a photovoltaic thermal module was manufactured using the process of sealing photovoltaic converters with a two-component polysiloxane compound.

State Policy In The Field Of Alternative Energy Sources In The Conditions Of Ensuring Energy Security Of Ukraine

The article analyses features of state policy in the field of alternative energy sources, particularly replacing traditional energy resources with alternative energy sources, aiming to reduce the energy intensity of Ukraine’s gross domestic product and ensure the state’s energy security. It is noted that Ukraine has significant potential for developing alternative energy sources, particularly wind energy, solar energy, bioenergy, hydropower, and geothermal energy. An analysis of the growth dynamics of the installed capacity of alternative energy source facilities operating under the «green» tariff has shown that solar energy is currently the most developed in Ukraine. This creates a foundation for further development of wind and bioenergy. The main practical benefits of energy storage systems are highlighted, including ensuring electricity supply to businesses when the external grid is disconnected, storing cheap electricity during excess capacity, and supplying it during peak demand when it is more expensive. Additionally, these systems have the potential to support and restore grid frequency. Storing surplus energy from solar power plants can increase the overall efficiency of the energy system. The author identifies the main tasks to be implemented within state policy to ensure energy security. These include investing in the restoration and decentralization of the energy system (increasing the share of electricity production from alternative energy sources, including the construction of wind and solar power plants, as well as energy storage facilities for the development of energy storage technologies produced from renewable sources), building biomethane production capacities, introducing new types of environmentally friendly fuels, increasing the construction of interconnectors with ENTSO-E to integrate Ukraine’s electricity system with the European power grid, enhancing the localization of energy storage systems, implementing innovative and efficient technologies in the electricity distribution sector, including smart grids, microgrids, and «vehicle-to-grid» systems, and resolving issues related to the «green» tariff.

Anaerobic valorization of sewage sludge pretreated through hydrothermal carbonization: Volatile fatty acids and biomethane production

Hydrothermal carbonization (HTC) emerged as an effective technology for the treatment of various types of wet biomass and organic residues, including sewage sludge, offering the potential for sludge reduction and resource recovery. HTC pretreatment impact on downstream sludge fermentation is investigated. Results obtained at optimal conditions for HTC pretreatment (170 °C for 30 min) indicated that soluble carbon was significantly increased in the liquid fraction, enhancing feedstock availability for fermentation. Semi-continuous fermentation of HTC-treated sludge resulted in a stable process in which a mixed microbial community produced volatile fatty acids (VFAs) with longer chain acids content, acidification yield of 0.59 ± 0.05 g COD-VFA g−1 CODin and volumetric productivity of 1.6 ± 0.5 g COD-VFA L−1 d−1. Biomethane Potential tests evidenced high values for hydrochar. Overall, the HTC pretreatment enables improved conversion efficiencies, in the view of valorizing the liquid for VFA synthesis and the hydrochar for biomethane production.

A study on value addition of cow dung-based anaerobic sludge for biomethane and bio-oil production via co-liquefaction with rice straw and clam shells as a catalyst.

The waste management sector is moving towards sustainable approaches for facilitating resource-recovery possibilities. Agriculture residue (rice straw), cow dung (cattle waste), and clam shells from the ocean are the primary waste materials possessing a huge value addition opportunity. In this study, the effective usage of rice straw and anaerobic sludge from cow dung for bio-energy production was studied. Cow dung was initially anaerobically processed for the generation of biomethane and sludge in a digester for a retention time of 40 days. The anaerobic sludge with rice straw was hydrothermally processed in varying proportions of 1 : 0, 0 : 1, 1 : 1,1 : 2, 2 : 1, 3 : 1, 1 : 3 and temperatures of 240-360 °C for 1 hour with varying biomass loads of 50, 75, 100, 125, and 150 g. Additionally, clam shells, one of the best bioresources, were used as a catalyst in the hydrothermal process at concentrations of 0.2-1 wt%. The maximum bio-oil produced was 36.23 wt% at a temperature of 320 °C, with a biomass load of 100 g, mixed proportion of 2 : 1 and catalyst loading of 0.6 wt%. The produced bio-oil comprised hydrocarbons, aldehydes, and carboxylic acids, as confirmed through GC-MS. In the anaerobic study, ≈0.018 m3 cumulative gas was produced at a retention time of 40 days. The biochar had a higher carbon content and its feasibility for further usage shows promise towards sustainability.

Goat Manure Potential as a Substrate for Biomethane Production—An Experiment for Photofermentation

This article presents the current state of biogas (biomethane) production technology—an example of the use of goat manure in terms of photofermentation efficiency. The theoretical and experimental potential of biomethane using biodegradability for anaerobic fermentation of goat manure was indicated. Goat manure was tested for its elemental composition to determine the suitability of this raw material for biogas production. The quality of biogas produced under atmospheric conditions from goat manure placed in a reactor (photodigester) was assessed. An attempt was made to determine the process conditions for immobilization on a goat manure bed (depending on the research material collected), which allows for demonstrating the activity of the fermentation bacterial flora, thus influencing the amount of biogas (biomethane) produced in the reactor. A mechanism for the photofermentation process involving the production of biomethane was developed. The novelty of this article is the development of the use of goat manure in an innovative way, pointing to the development of the biomethane industry. When comparing goat manure, active group (compact bed), it should be noted that K 3.132%, Na 0.266%, Ca 1.909% and Mg 0.993% are lower values compared to the material with values of K 3.397%, Na 0.284%, Ca 1.813% and Mg 0.990% which are higher. This is undoubtedly due to the presence of nutrients in the deposit that support the biomethane production process. The active group (compact bed) material A shows a dynamic increase in biomethane production with lower nutrient values. However, material B, having a higher percentage of ingredients, shows stabilization of biomethane production after the sixth month of the process. Technological trends and future prospects for the biomethane sector were initiated.

Biogas potential of organosolv pretreated wheat straw as mono and co-substrate: substrate synergy and microbial dynamics

Anaerobic digestion (AD) technology can potentially address the gap between energy demand and supply playing a crucial role in the production of sustainable energy from utilization of biogenic waste materials as feedstock. The biogas production from anaerobic digestion is primarily influenced by the chemical compositions and biodegradability of the feedstock. Organosolv-steam explosion offers a constructive approach as a promising pretreatment method for the fractionation of lignocellulosic biomasses delivering high cellulose content.This study showed how synergetic co-digestion serves to overcome the challenges of mono-digestion's low efficiency. Particularly, the study evaluated the digestibility of organosolv-steam pretreated wheat straw (WSOSOL) in mono as well as co-digesting substrate with cheese whey (CW) and brewery spent grains (BSG). The highest methane yield was attained with co-digestion of WSOSOL + CW (338 mL/gVS) representing an enhanced biogas output of 1–1.15 times greater than its mono digestion. An ammonium production was favored under co-digestion strategy accounting for 921 mg/L from WSOSOL + BSG. Metagenomic study was conducted to determine the predominant bacteria and archaea, as well as its variations in their populations and their functional contributions during the AD process. The Firmicutes have been identified as playing a significant role in the hydrolysis process and the initial stages of AD. An enrichment of the most prevalent archaea genera enriched were Methanobacterium, Methanothrix, and Methanosarsina. Reactors digesting simpler substrate CW followed the acetoclastic, while digesting more complex substrates like BSG and WSOSOL followed the hydrogenotrophic pathway for biomethane production. To regulate the process for an enhanced AD process to maximize CH4, a comprehensive understanding of microbial communities is beneficial.

Assessment of the possibility of obtaining biohydrogen during decarbonization of municipal solid waste landfills

The article discusses the current problem of energy utilization of municipal solid waste, most of which is currently buried in landfills. An assessment of greenhouse gas emissions from these anthropogenic objects is provided. It is noted that a promising direction for utilization of landfill biogas is the production of biohydrogen. The authors present the results of laboratory studies on the production of biomethane from organic waste with its further conversion into biohydrogen. Using the example of a large landfill for municipal solid waste, a possible geo-ecological effect is shown by reducing greenhouse gas emissions during the energy utilization of biogas.

Bioaugmentation by enriched hydrogenotrophic methanogens into trickle bed reactors for H2/CO2 conversion

Biomethanation represents a promising approach for biomethane production, with biofilm-based processes like trickle bed reactors (TBRs) being among the most efficient solutions. However, maintaining stable performance can be challenging, and both pure and mixed culture approaches have been applied to address this. In this study, inocula enriched with hydrogenotrophic methanogens were introduced to to TBRs as bioaugmentation strategy to assess their impacts on the process performance and microbial community dynamics. Metagenomic analysis revealed a metagenome-assembled genome belonging to the hydrogenotrophic genus Methanobacterium, which became dominant during enrichment and successfully colonized the TBR biofilm after bioaugmentation. The TBRs achieved a biogas production with > 96 % methane. The bioaugmented reactor consumed additional H2. This may be due to microbial species utilizing CO2 and H2 via various CO2 reduction pathways. Overall, implementing bioaugmentation in TBRs showed potential for establishing targeted species, although challenges remain in managing H2 consumption and optimizing microbial interactions.

Biomethane and Green Hydrogen Production Potential from Municipal Solid Waste in Cape Coast, Ghana.

Biomethane and hydrogen are promising elements in the transition towards sustainable energy, due to their capacity to mitigate greenhouse gas emissions. In Ghana, efforts to promote sustainable waste valorization for energy production are underway; however, organic waste conversion into biomethane and hydrogen still needs to be expanded. This study aims to evaluate the potential of producing biomethane and hydrogen from the municipal solid waste in Cape Coast, and their injection into the national gas grid. The upgrading biogas obtained from anaerobic digestion of food/organic wastes was used to generate biomethane. The modified Buswell Equation and data from literature were used to estimate the amount of biomethane and hydrogen. The environmental impact was assessed using the CO2 equivalent emissions. The findings reveal that Cape Coast generated approximately 6,400 tons of food waste in 2021, with a projection to 11,000 tons by 2050. Biomethane and hydrogen quantities was estimated at 3,700,000 m³ and 784,000 kg in 2021, respectively. Their projection reaches to 6,600,000 m³ and 1,400,000 kg by 2050. Converting waste into biomethane and hydrogen is an eco-friendly method of their management and use for renewable energy in Ghana. Strategies can be integrated into Ghana national energy policies to encourage waste-to-energy projects.

RETRACTED: Life cycle analysis of biowaste-to- biogas/biomethane processes: Cost and environmental assessment of four different biowaste scenarios organic fraction of municipal solid waste and secondary sewage sludge

Biowaste-to-biogas processes have been introduced to design a valuable and green renewable plant to achieve a sustainable society and environment. The biomethane production process through biogas upgrading instead of designing a combined heat and power (CHP) system can be more attractive. This study presents a life cycle analysis (LCA) from both cost and environmental standpoints for four biowaste-to-biogas/biomethane process scenarios. Biogas production is achieved through anaerobic co-digestion of the organic fraction of municipal solid waste (OF-MSW) and secondary sewage sludge (S-SS), incorporating a pre-treatment process based on the dark co-fermentation process (DCFP). Each scenario offers distinct methods for utilizing the hydrogen-rich gas and biogas, with varying degrees of energy recovery and efficiency. Two sensitivity studies were conducted under various utilizations of the recovered biomethane and the anticipated electricity mix. Scenario SC-1 (CHP-from-biogas) was found to be the most co-friendly favorable in eight out of eleven impact categories (under the CML/IA technique). Further, biogas upgrading-integrated options exhibited lower impacts. Replacing biomethane instead of petrol in scenarios with upgraded biogas was identified as the most effective approach against climate change. Financial analysis indicated that all layouts are economically viable, each demonstrating a positive NPV over a 20-year period (up to $11.57 million).

Impacts of material characteristics on the anaerobic digestion kinetics and biomethane potential of American bourbon and whiskey stillage

Stillage of American whiskey (e.g., bourbon) manufacturing is an abundant byproduct that is distinguished from fuel ethanol and malt whisky stillage materials by its highly inconsistent nature due to variability in mash bill composition. The impact of stillage physicochemical characteristics on biomethane production through anaerobic digestion was assessed by characterizing American whiskey stillage samples before batch biochemical methane potential tests of whole stillage. A maximum methane yield of 419 Nml CH4/g VS was obtained under food to microbe ratio (F: M) of 0.5 and organic loading rate (OLR) of 10 g VS/L while digester instability was noted under F: M ratios exceeding 0.5 under batch production. Methane production was significantly influenced by the mash bill composition with lowest methane yields obtained with higher rye content (rye whiskey) and highest methane yields obtained with higher corn content (bourbon or corn whiskey). A multiple linear regression model including C, P, N, and Na was able to accurately describe the methane yield (R2 = 0.93). This study provides valuable insights to aid the design of anaerobic digesters generating renewable natural gas from heterogeneous American whiskey stillage.

Closing the loop: Structural, environmental and regional assessments of industrial symbiosis

Regional symbiosis, based on industrial symbiosis principles, is one possible strategy for managing the environmental impact of human activities and the increasing risks associated with resource availability. An assessment is needed to ensure the benefits of implementing synergies in a region. Current research focuses on the environmental and structural analysis of symbiosis networks but lacks frameworks that consider the benefits of symbiosis at the regional scale. By combining ecological network analysis (ENA), circularity metrics and the life cycle assessment (LCA) approach, this study intends to analyze the benefits brought by expanding industrial symbiosis to a broader region. Through the analysis of different symbiosis scenarios under two energetic cases (electricity and biomethane production), the study showed that implementing regional symbiosis was a lever to improve the robustness, the circularity and the environmental impact of the system. The environmental dimension was lowly affected by the scenario changes, but they provided a wider effect on regional metrics. The change in energetic production did not bring significant differences in the results. This study also showed that the structural metrics followed a different trend than the regional and environmental metrics, revealing the complementary views that were brought by the multidimensional analysis. It advocates for a holistic assessment of systems and highlights network structural organization, which should be accounted for in regional sustainability planning.

Bridging the Gap between Biowaste and Biomethane Production: A Systematic Review Meta-Analysis Methodological Approach

Bridging the Gap between Biowaste and Biomethane Production: A Systematic Review Meta-Analysis Methodological Approach