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The Perfect Storm
Published in Christian Reynolds, Tammara Soma, Charlotte Spring, Jordon Lazell, Routledge Handbook of Food Waste, 2020
New solutions emerged in the late twentieth century. Food waste and other organic material could be converted into biogas via anaerobic digestion – the process by which microorganisms break down organic material into methane. The science behind anaerobic digestion had been known for more than a century, but it garnered new interest during the oil crisis of the 1970s (Klinkner 2014). Beginning in the 1990s, Germany took the lead in constructing anaerobic digestion plants. Biogas production diverts organic waste from landfill and generates a renewable energy source that can be used to power vehicles, generate electricity, and supply fuel to homes and businesses. Anaerobic digestion facilities also produce nutrient-rich “digestate” which can be used as fertilizer. Despite these positives, low oil prices in the late 1990s made it unclear whether anaerobic digestion programs were financially viable.
Third World energy: options for the future
Published in John Soussan, Primary Resources and Energy in the Third World, 2019
Biogas is a methane-based fuel produced from the anaerobic digestion of organic material (generally dung) by micro-organisms. Again developed extensively in China, where communal digesters have proved successful, this technology has been tried in many countries. There are numerous smaller, household digesters in India and trial projects throughout the Third World. The cost of the digesters, the effort involved in collecting dung and the cost and complexity of gas-using appliances have limited their applicability. In parts of India where well-off landowners have built digesters, their greatly increased needs for dung have resulted in poor landless families losing their rights to collect this fuel for traditional use, a classic example of where an ‘appropriate’ technology has helped the rich at the expense of the poor.
Greenhouse Gas Emissions through Biological Processing of Solid Waste and Their Global Warming Potential
Published in Sunil Kumar, Zengqiang Zhang, Mukesh Kumar Awasthi, Ronghua Li, Biological Processing of Solid Waste, 2019
Mukesh Kumar Awasthi, Hongyu Chen, Sanjeev Kumar Awasthi, Tao Liu, Meijing Wang, Yumin Duan, Jiao Li
Anaerobic digestion is the process of microbial catabolism in which organic matter decomposes and then produces biogas in the absence of nitrate, sulfate, and oxygen. Organic waste anaerobic fermentation biogas need to go through the basic classification, broken treatment, and then add a certain amount of water, control the appropriate temperature and maintain anaerobic conditions, through the fermentation of bacteria, hydrogen production of acetic acid bacteria, consumption of hydrogen production of acetic acid bacteria, and other metabolic effects of fermented microorganisms, through different ways of decomposition, and finally produce methane gases (Killilea et al. 2000). Organic waste in the complex organic matter contained in the role of bacteria hydrolase; the formation of the corresponding complex organic matter, such as monosaccharides, fatty acids, amino acids; and then in the hydrolysis of bacteria intracellular enzyme, the decomposition of acetic acid, acid, butyric acid, lactic acid, ethanol, and CO2 and H2, and then in the hydrogen production of acetic acid or acetic acid production of acetic acid bacteria under the action of the above products into acetic acid, and then through the hydrogen production of methane or acetic acid production of methane. Under the action of bacteria, decomposition of acetic acid produces methane. The anaerobic fermentation process is illustrated in Figure 6.2.
Densification of Synechococcus subsalsus biomass by chitosan coagulation for biogas production
Published in Environmental Technology, 2023
Laura Benevides dos Santos, Maria Clara de Oliveira, Magali Christe Cammarota, Isabelli Dias Bassin
Depending on the route used, algal biomass can be converted to biodiesel, bioethanol, biobutanol, biogas/biomethane, or biohydrogen [6,7]. Biodiesel is generated from the chemical reaction between the lipids extracted from the biomass and an alcoholic solvent in the presence of a chemical or enzymatic catalyst [8]. The fermentation of simple sugars by yeasts into ethanol is the core process in bioethanol production. Anaerobic fermentation of polysaccharides by bacteria of the genus Clostridia yields biobutanol [9]. Anaerobic digestion is a complex biological process in which organic matter is consumed by many microorganisms without oxygen, resulting in biogas. Biogas upgrading allows biomethane recovery [10]. Dark fermentation also occurs in the absence of oxygen, and it is equivalent to the first two steps of anaerobic digestion (hydrolysis and acidogenesis), with the release of H2, CO2, volatile fatty acids, and low molecular weight alcohols, focusing on the recovery of biohydrogen [11].
A review of response surface methodology for biogas process optimization
Published in Cogent Engineering, 2022
Solal Stephanie Djimtoingar, Nana Sarfo Agyemang Derkyi, Francis Atta Kuranchie, Joseph Kusi Yankyera
Anaerobic digestion, as defined by (Mukumba et al., 2016) and (Abdeshahian et al., 2016), is a biological process that takes place in the absence of oxygen and results in the production of methane through the decomposition of biomass. Biomass which is considered as an organic matter, is a biodegradable portion of materials such as agriculture residues (vegetal and animal), forest residues and waste (industrial and municipal; Umana et al., 2020). Organic materials are made up of carbon, oxygen, hydrogen and nitrogen (Umana et al., 2020). Anaerobic digestion is a good technology for waste management because it maximizes energy production and minimizes the cost of treatment of organic materials (municipal solid waste, food waste, animal manure, agricultural residues, sewage, industrial waste and human excrement; Abdeshahian et al., 2016; Shen et al., 2015). It is also a great solution to wastewater pollution which is one of the most important environmental problems in the world today (Buaisha et al., 2020).
Anaerobic co-digestion of oil refinery waste activated sludge and food waste
Published in Environmental Technology, 2022
Tayane Miranda Silva de Castro, Magali Christe Cammarota, Elen Beatriz Acordi Vasques Pacheco
Although OR-WAS is considered a hazardous waste, due to its potential negative impacts when improperly disposed of, its high energy potential can be harnessed [2,7]. Anaerobic digestion, whereby organic waste is converted into biogas by the action of a microbial population in the absence of oxygen, can be used to extract the energy contained in the secondary sludge. Biogas, an important energy source, contains about 60% methane. In addition to producing energy, anaerobic digestion stabilizes the organic load of sludge and reduces the concentration of pathogenic microorganisms, producing a residue rich in assimilable nutrients that can be used as a biofertilizer. Among its advantages are the low energy requirement for the operation, lack of aeration, smaller installation area, as well as high organic matter removal and biogas recovery rates [8].