Biogas Utilization Research Articles

Biogas utilization from municipal solid waste in developing countries towards the transition to sustainable development – The Colombian case

Sustainable Development (SD) encompasses the enhancement of quality of life through social, economic, and environmental pillars. Biogas utilization from landfills (BUL) is a widely adopted technique in the United States and some European regions. However, myths persist regarding its implementation in Latin American and Caribbean countries, as well as in certain low-and middle-income economies. This article aims to assess the electricity generation potential in Colombia's major cities and highlight the significant contribution of BUL in achieving public policies objectives for SD and climate change mitigation. The study underscores that Colombia undervalues the potential of BUL when formulating public policies, overlooking its substantial impact in fulfilling at least 14 of the 17 Sustainable Development Goals (SDGs).

Development of Ni–Mo carbide catalyst for production of syngas and CNTs by dry reforming of biogas

Biogas has been widely regarded as a promising source of renewable energy. Recently, the direct conversion of biogas over heterogeneous catalysts for the simultaneous production of syngas and carbon nanotubes exhibits a high potential for full utilization of biogas with great benefits. Involving the combined dry reforming of methane and catalytic decomposition of methane, the efficiency of process is strongly depended on the catalyst activity/stability, mainly caused by carbon deposition. In this study, Ni–Mo catalyst is engineered to provide a life-long performance and perform high activity in the combined process. The surface modification of catalysts by a controlled carburization pretreatment is proposed for the first time to produce a carbide catalyst along with improving the catalyst stability as well as the reactivity for direct conversion of biogas. The performance of as-prepared carbide catalysts is investigated with comparison to the oxide and metallic ones. As a result, the Ni–Mo2C catalyst exhibited superior activity and stability over its counterparts, even though the condensed nanocarbon was largely grown and covered on the surface. In addition, up to 82% of CH4 conversion and 93% of CO2 conversion could remain almost constant at 800 °C throughout the entire test period of 3 h under a high flowrate inlet stream of pure biogas at 48,000 cm3 g−1 h−1. The XPS spectra of catalysts confirmed that the presence of Mo2C species on the catalyst surface could promote the stability and reactivity of the catalyst, resulting in higher productivity of carbon nanotubes over a longer time.

Novel adaptive power distribution master–slave control strategy for a biogas–solar–wind battery islanded microgrid based on a microturbine

As many countries increase their investment in the field of renewable energy, technological research and development has increased on establishing biogas–solar–wind battery islanded microgrids (BSWBIMs) based on biogas generation technology. In BSWBIMs, multiple distributed generators (DGs) are controlled to share either the lack or surplus of power throughout the microgrid. To improve the reliability and economic efficiency of the system, a reasonable control strategy is indispensable. In this paper, a novel adaptive power distribution master–slave (APD–MS) control strategy is proposed to maintain the system voltage and frequency within the Chinese national grid requirements. Moreover, compared with the conventional master-slave control strategy, the proposed control strategy can solve the problem of high dependence on the master DG. Notably, the proposed control strategy can improve the biogas utilization efficiency, system reliability and system stability. The theoretical analysis and software simulation based on BSWBIMs at low voltage levels demonstrate the effectiveness and superiority of the proposed APD–MS control strategy.

Organic Leachate and Biogas Utilization in Outdoor Microalgae Cultivation Under Alkaline Conditions at Pilot-Scale

The performance of an outdoor pilot-scale system consisting of a high rate algal pond interconnected to an absorption bubble column and seeded with a microalgal-bacterial consortium is presented. Biogas and organic leachate (from food waste anaerobic hydrolysis) were used as sources of CO2 and nutrients for the consortium, respectively. The removal efficiencies for CO2 and H2S from biogas were 80.0% and 99.9%, respectively, provoking a methane content in the utilized biogas of approximately 55 vol% for anaerobically-produced biogas and 90 vol% for a prepared gaseous mixture. The molecular oxygen produced by microalgae photosynthesis induced undesirable cumulation of O2 in utilized biogas up to 5%vol. The organic leachate was diluted in an alkaline mineral medium (15:1 v/v), and this rich-nutrient mixture was fed to the system at a hydraulic retention time of 138 d. The biomass productivity applying organic leachate and anaerobically-produced biogas was 2.6 g m−3 d−1, nine times lower than biomass productivity achieved when only mineral salt medium was fed, suggesting the existence of limited nutrient bioavailability. Microalgal-bacterial community shifts evaluated through molecular and morphological methods showed that a robust and stable photosynthetic population was maintained throughout the entire operation of the system, formed mainly by Picochlorum sp., Pseudanabaena sp., Spirulina sp., and Nitzschia sp., as well as heterotrophic bacteria and some microalgae predators. The valued by-products after waste utilization were clean and highly calorific biogas besides microalgae biomass, where the commercialization of the latter would determine the economic viability of biogas and leachate utilization.Graphical

Insights into the drivers of biogas for the purpose of energy transition in Mokambo: a case study of a peri-urban area of Zambia

This study focuses on a wide range of socio-political factors that contribute to the production and utilization of biogas in Mokambo, a peri-urban area of Mufulira in Zambia. The study employed a variety of qualitative techniques which includes in-depth interviews, focus group discussions (FGDs), and case study to answer the research questions. Revealed here is that there are essentially five issues driving biogas production: environmental protection and climate change; economic view and sustainable development; poverty reduction and international aid; and agricultural production. The research identifies four types of problems: institutional, situational, infrastructure and technical, and dispositional. The study emphasizes the local government’s effort to improve its strategies in relation to community awareness for the production and adoption of biogas in Zambia. This is combined with ongoing dialogue among stakeholders with a holistic approach towards a smooth and steady renewable energy transition.

Distribution of PCDD/Fs in a food waste anaerobic digestion process with biogas utilization

Distribution of PCDD/Fs in a food waste anaerobic digestion process with biogas utilization

Upgradation of methane in the biogas by hydrogenation of CO2 in a prototype reactor with double pass operation over optimized Ni-Ce/Al-MCM-41 catalyst

The upgradation of methane in biogas by hydrogenation of CO2 has been currently recognized as a promising route for efficient full utilization of renewable biogas with potential benefits for storage of renewable hydrogen energy and abatement of greenhouse gas emission. As a main constituent of biogas, CO2 can act as a backbone for the formation of additional CH4 by hydrogenation, then producing higher amounts of biomethane. In this work, the upgradation process was investigated in a prototype reactor of double pass operation with vertical alignment using an optimized Ni-Ce/Al-MCM-41 catalyst. The experimental results show that the double pass operation that removes water vapor during the run can significantly increase CO2 conversion, resulting in higher CH4 production yield. As a result, the purity of biomethane increased by 15% higher than a single pass operation. In addition, search for optimum condition of the process was carried out within an investigated range of conditions including flowrate (77–1108 ml min−1), pressure (1 atm–20 bar), and temperature (200–500 °C). The durability test for 458 h was performed using the obtained optimum condition, and it shows that the optimized catalyst can perform excellent stability with negligible influence by the observed change in catalyst properties. The comprehensive characterization on physicochemical properties of fresh and spent catalysts was performed, and the results were discussed.

Microbial protein production from sulfide-rich biogas through an enrichment of methane- and sulfur-oxidizing bacteria

This study evaluated the possibility of combining methane oxidizing bacteria (MOB) with sulfur oxidizing bacteria (SOB) to enable the utilization of sulfide-rich biogas for microbial protein production. For this purpose, a MOB-SOB mixed-culture enriched by feeding both methane and sulfide was benchmarked against an enrichment of solely MOB. Different CH4:O2 ratios, starting pH values, sulfide levels and nitrogen sources were tested and evaluated for the two enrichments. The MOB-SOB culture gave promising results in terms of both biomass yield (up to 0.07 ± 0.01 g VSS/g CH4-COD) and protein content (up to 73 ± 5% of VSS) at 1500 ppm of equivalent H2S. The latter enrichment was able to grow also under acidic pH (5.8–7.0), but as inhibited outside the optimal CH4:O2 ratio of 2:3. The obtained results show the capability of MOB-SOB mixed-cultures to directly upcycle sulfide-rich biogas into microbial protein potentially suited for feed, food or biobased product applications.

Waste2Watts: Techno-Economic Feasibility of Biogas-Fed SOFC Power System Integrated with Biogas Cleaning Unit and Carbon Capture Technologies

Solid oxide fuel cell (SOFC) systems show immense potential for efficient biogas utilization, which can significantly reduce carbon emissions by integrating with biogas cleaning units and carbon capture technologies. Despite the significant benefits, the high cost of the integrated system presents a challenge. Therefore, a techno-economic assessment is necessary to evaluate the feasibility of the integrated system and provide guidelines for cost reduction. The ideal capacity for an integrated biogas-fed SOFC power system ranges between 20 kW to 200 kW. Firstly, a comparison of different biogas types and stack technologies is conducted to evaluate the system performance. Secondly, a techno-economic investigation of the feasibility of different system designs is performed by comparing different carbon capture technologies with various biogas cleaning units. The study results can facilitate the optimization of the integrated system's design and operation and pave the way for large-scale implementation of SOFC technology in the energy industry.

SISTEM MONITORING BIODIGESTER BERBASIS ARDUINO NANO

Biogas is a renewable energy source that is now a trend among the wider community because biogas fermented from feces or organic waste is relatively easy to do by ordinary people. Biogas can be a solution to overcome rising fuel prices due to depletion of petroleum. the price of fuel that rises due to depletion of petroleum. the utilization of biogas is currently felt to be less than optimal because the control system is still manual and less effective. Biodigester is a gas collection system for methane, carbon dioxide and other mixed gases obtained from the decomposition of organic materials such as cow dung by bacteria that cause methanogens in an anaerobic biodigester. With the Smart Biodigester Control System we can see waste data and can make the system more optimal, namely with the automatic biogas control system in the biodigester. In a tank that is 40 cm high we can see the waste data in the tank and the AC motor in the tank will stop when at a height of 35 cm. Strobe is not active if the pressure value does not exceed 0.4 Bar. The DC valve is active from the pH data value exceeding 7.5. The success rate is 98%, the remaining 2% is further research.

Establishment of a Research Focus on Resilient Sustainable Climate Neutral Agricultural Production—Resilient Farming Initiative

Efficient and sustainable agricultural production is a pivotal factor in meeting the nutritional needs of an expanding global population. However, it is imperative to optimize national, regional and local effectiveness to support government initiatives towards climate neutrality and resilience, while simultaneously ensuring economic viability for farmers. A significant reduction in the cost of goods must be accompanied by a decrease in their global warming potential contribution to maintain competitiveness in the world market. As such, it is necessary to adopt practices that enhance productivity while minimizing environmental impacts. This paper discusses potential solutions for the sustainable enlargement of botanical product portfolios towards essential oil products and natural extracts for value-added products, such as natural pharmaceuticals, cosmetics, agrochemicals and materials by direct waste valorization. Contributions from the fields of automation and digitalization provide the basic technology for the realization of the approaches presented. Agricultural photovoltaics can contribute to the goal of the reduction of the cost of goods and global warming potential, such as the already established utilization of biogas. The potential of the research initiative described is demonstrated by basic data on key characteristic numbers and costs from the literature. The economic potential for climate neutrality and the reduction of global warming potential contribution is seen in magnitudes of factors 5–10. A research initiative is recommended and exemplified for the industrialization of such integrated processing.

Strategic Thinking for Bold Goals

Strategic Thinking for Bold Goals

Physical Model for the Sustainable Transformation of Human Waste into Biogas in Housing

The study presents the conversion of waste to biogas and its implications for housing development by analysing biogas production approaches and utilisation methods. The study looked at the method of biogas production that is appropriate for generating the incessant operation of biogas schemes in housing, as well as the factors for establishing biogas plants in residential buildings. An experimental variant that includes combinations of liquid human and animal waste compost and houseplant extracts was developed and established to create biogas and increase its yield. The gas engine assessments were carried out for energy applications. The eco-energy arrangement was fabricated by considering the precise housing and local situations. The study takes on one household member in a residential area in Ibadan as a case study, and consequently, the amount of liquid humanoid manure generated was 438 m3/year and 2.4 m3 of biogas was generated per day. The findings indicated that human fluid manure should be aided in producing the essential biogas measure and fuel quality and quantity for the household’s energy demand and supply requirements and needs. The study generated a simple biogas application and production method by developing variants and alternatives in which both the waste disposal and the biogas production objectives were accomplished together. The study concluded that for sustainable transformation of human waste into biogas in housing, it is vital to include a biomass plant within the household design scheme, in which biogas plants are in constant operation and biogas is constantly produced for household energy use.

A Scoping Review of Options for Increasing Biogas Production from Sewage Sludge: Challenges and Opportunities for Enhancing Energy Self-Sufficiency in Wastewater Treatment Plants

Treating municipal wastewater is a complex and costly process. With rising energy costs and sustainability targets, wastewater treatment plants (WWTPs) are looking for alternatives to reduce operating costs and carbon dependence. Anaerobic digestion is the most common and established technology used in WWTPs to treat sludge since it can potentially improve energy recovery and reduce sewage treatment costs, mainly due to the generation of biogas. Biogas is a renewable energy resource and can be used in several applications, including heating and producing electricity. By exploring the biogas potential, WWTPs can reduce their operating costs and energy demands. The objective of this paper is to conduct a scoping literature review in order to provide the key concepts underpinning alternatives to improve biogas production and utilisation in WWTPs. In addition, this study aims to provide an overview of the current state-of-the-art that may serve as a quick reference for the research community, WWTP operators, and engineers, including definitions and a general overview of the current state of biogas technologies around the world. Methods to increase biogas production, including co-digestion, pre-treatment, and biological hydrogen methanation, are reviewed, and the alternatives to using biogas are also summarised. This review has identified that co-digestion was the most efficient technique to improve biogas production and methane yield, while pre-treatment of sludge improved sludge biodegradability and reduced sludge treatment costs but also enhanced biogas production. Although many studies have explored different methods to improve biogas production in WWTPs, there is still a need for further investigation, especially regarding the techno-economic feasibility of these methods in full-scale facilities. The current challenges are mainly related to the need for extra investment and increased operating costs to integrate the new techniques into the current system. There is a great interest in alternatives to improve energy efficiency and self-sufficiency in WWTPs. This work provides an important review of the increasing number of recently published research papers that focus on improving biogas generation from sewage sludge in WWTPs.

Economic Value Estimation of Biogas Utilization in Public Wastewater Treatment Plants of the Republic of Korea

This paper presents economic value estimation of improved biogas utilization systems of public wastewater treatment plants in Republic of Korea. Since a large amount of biogas produced at digestion facilities is being wasted as a by-product, the biogas energy utilization system needs to be enhanced. In this paper, three operating options able to utilize the produced biogas are proposed, and then their monetary benefits are estimated by means of net present value calculation. Real operational data from the public wastewater treatment plant located in Sejong city, Republic of Korea, is used to reflect a variation of the rated daily gas production and its concentration according to the weather and seasons, resulting in calculating more reliable results. Additionally, to minimize the estimation errors due to uncertainties of the gas concentration and the gas selling price, a Monte Carlo simulation considering the variation of critical input data is carried out. As a result, the proposed approach can lead to better decisions in selecting the suitable biogas utilization system by forecasting the ranges of possible economic values.

Plasma-catalytic reforming of biogas into syngas over Ni-based bimetallic catalysts

Biogas reforming to syngas is an attractive route for the efficient utilization of biogas. In this work, plasma-catalytic dry reforming of biogas into value-added fuels and chemicals over Ni-based bimetallic catalysts was achieved using dielectric barrier discharge (DBD). The coupling DBD with 10Ni3Co exhibited the best reaction performance, reflected by the highest gas conversion, main gas product yield and selectivity, and fuel production efficiency (FPE). This hybrid process also favored the suppression of carbon deposition on the catalyst surface and the reduction of energy cost for both gas conversion and product formation. The maximum CO2 and CH4 conversion (29.8% and 49.1%) was obtained when the discharge power was 60 W, while a low discharge power (30 W) led to the highest FPE of 12.3%. By using Ni-based catalysts, we were able to tune the product distribution, favoring the generation of C3-C4 hydrocarbons and syngas while reducing the production of C2 hydrocarbons, with 10Ni3Co providing the most favorable results. Compared to other spent catalysts, the lowest carbon deposition (2.9%) was detected on the spent 10Ni3Co after 150 min of plasma reforming. Catalyst characterizations and density functional theory (DFT) calculations showed that the 10Ni3Co catalyst was superior due to a combination of factors such as a higher specific surface area, improved capability to adsorb CO2, strong interactions between the metals and the support, enhanced reducibility and the formation of a Ni-Co alloy. Furthermore, a simplified kinetics model was developed to better understand the effects of Ni-based bimetallic catalysts on the overall energy constant for the conversion of reactants in plasma-catalytic reforming of biogas.

Biogas utilization without desulfurization pretreatment in a bioelectrochemical system

Utilizing biogas as a fuel for heating and power generation usually requires desulfurization pretreatment. In this study, the biogas utilization without desulfurization pretreatment in a bioelectrochemical system (BES) was explored. The results showed that the biogas-fueled BES was successfully started up within 36 d and the presence of hydrogen sulfide promoted both methane consumption and electricity generation. The optimal performance (i.e., a methane consumption of 0.523 ± 0.004 mmol/d, a peak voltage of 577 ± 1 mV, a coulomb production of 37.86 ± 0.43C/d, a coulombic efficiency of 9.37 ± 0.06 % and the maximum power density of 2.070 W/m3) was obtained under bicarbonate buffer solution and 40 °C conditions. The addition of 1 mg/L sulfide and 5 mg/L L-cysteine facilitated methane consumption and electricity generation. In the anode biofilm, the dominant bacteria were Sulfurivermis, unclassified_o__Ignavibacteriales and Lentimicrobium, while Methanobacterium, Methanosarcina and Methanothrix were the predominant archaea. Besides, the metagenomics profiles reveal that anaerobic methane oxidation and electricity generation were closely related to sulfur metabolism. These findings provide a novel approach for utilizing biogas without desulfurization pretreatment.

H2S Emission and Microbial Community of Chicken Manure and Vegetable Waste in Anaerobic Digestion: A Comparative Study

In order to solve the problem of H2S corrosion in biogas utilization, it is necessary to understand the characteristics and mechanisms of H2S production in chicken manure anaerobic digestion (CMAD) and vegetable waste anaerobic digestion (VWAD). In this study, lab-scale batch tests of CMAD and VWAD were conducted for 67 days at 35 °C. The results showed that sulfide was found to be the major form of sulfur in CMAD (accounting for 90%) and VWAD (70%). The average concentration of H2S was 198 ± 79 ppm in CMAD and 738 ± 210 ppm in VWAD. Moreover, 81% of total H2S was produced at 20 days of methane production in CMAD, but 80% of total H2S was produced in the first day in VWAD because of the rapid production of biogas and fermentation acidification. The sulfide ion equilibrium model could universally and feasibly predict the H2S production in CMAD and VWAD. The abundance of Firmicutes, Bacteroidetes, Proteobacteria and Euryarchaeota accounted for about 95% of the total microbes in both CMAD and VWAD; the influence of the fermentation stage on the microbial community was greater than that of the difference between CM and VW; the abundance of SRB was 0.01~0.07%, while that concerning organosulfur compounds fermentation was 22.8~30.5%. This study indicated that the H2S concentration of CMAD biogas was more than five times that of VWAD because CM is alkalescent but VW is acidic.

Prediction of the emission characteristics of biogas as a supplementary fuel in SI engines using CFD to assess its applicability

This study investigates the potential for the utilization of biogas as a supplementary fuel in a SI engine by studying the emission characteristics of a biogas-fuelled engine using computational fluid dynamics(CFD). Biogas is generated using a lab-scale floating drum bio digestor coupled to a SI engine to produce power. To determine the emission characteristics, the bio-digester and the combustion chamber of the SI engine with the desired specifications are modelled using the CREO software, and further Computational analysis is carried out using ANSYS FLUENT software. Emission parameters like Carbon monoxide (CO), Carbon dioxide (CO2), and Nitrous oxide (NOx) have been simulated for the SI engine utilizing biogas and gasoline. Computational results show that the bio-gas-operated SI engine shows less emission than gasoline. The results show that the CO emission decreased from 0.004 ppm to 0.035 ppm in gasoline and biogas modes, respectively. Also, the CO2 decreased from 0.021 ppm to 0.0052 ppm. The concentration of nitrous oxides in the emission shows a drastic decrease from 0.1343 ppm to 0.0234 ppm in gasoline and biogas mode. The significant reduction in emission characteristics when utilizing biogas as a fuel in SI engines against gasoline makes biogas an appealing fuel option for IC engines. applications.

Techno-economic-environmental assessment of the integration of power-to-X and biogas utilization towards the production of electricity, hydrogen, methane and methanol

Various routes for the valorisation of biogas towards methane and methanol and for electricity or hydrogen storage is assessed.