Topic
Biogas
About: Biogas is a research topic. Over the lifetime, 28571 publications have been published within this topic receiving 498545 citations.
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TL;DR: In this article, the authors compared different alternatives to the energy recovery from the municipal solid waste (MSW) generated in Brazilian cities, and concluded that the best option, which presented the best performance based on considered indicators, is the direct combustion of waste as fuel for electricity generation.
Abstract: Due to the lack of appropriate policies in the last decades, 60% of Brazilian cities still dump their waste in non-regulated landfills (the remaining ones dump their trash in regulated landfills), which represent a serious environmental and social problem. The key objective of this study is to compare, from a techno-economic and environmental point of view, different alternatives to the energy recovery from the Municipal Solid Waste (MSW) generated in Brazilian cities. The environmental analysis was carried out using current data collected in Betim, a 450,000 inhabitants city that currently produces 200 tonnes of MSW/day. Four scenarios were designed, whose environmental behaviour were studied applying the Life Cycle Assessment (LCA) methodology, in accordance with the ISO 14040 and ISO 14044 standards. The results show the landfill systems as the worst waste management option and that a significant environmental savings is achieved when a wasted energy recovery is done. The best option, which presented the best performance based on considered indicators, is the direct combustion of waste as fuel for electricity generation. The study also includes a techno-economical evaluation of the options, using a developed computer simulation tool. The economic indicators of an MSW energy recovery project were calculated. The selected methodology allows to calculate the energy content of the MSW and the CH4 generated by the landfill, the costs and incomes associated with the energy recovery, the sales of electricity and carbon credits from the Clean Development Mechanism (CDM). The studies were based on urban centres of 100,000, 500,000 and 1,000,000 inhabitants, using the MSW characteristics of the metropolitan region of Belo Horizonte. Two alternatives to recovering waste energy were analyzed: a landfill that used landfill biogas to generate electricity through generator modules and a Waste-to-Energy (WtE) facility also with electricity generation. The results show that power generation projects using landfill biogas in Brazil strongly depend on the existence of a market for emissions reduction credits. The WtE plant projects, due to its high installation, Operation and Maintenance (O&M) costs, are highly dependent on MSW treatment fees. And they still rely on an increase of three times the city taxes to become attractive.
226 citations
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TL;DR: In this paper, a series of laboratory experiments were performed in continuously stirred tank reactors at mesophilic conditions, fed semi-continuously with various mixtures of diluted poultry manure and whey.
226 citations
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TL;DR: In this article, an investment decision kit for economic evaluation of biogas plant projects based on agricultural feedstocks is presented, which can be used to compare different conditions adapted to local situations to treat the targeted residues.
Abstract: Anaerobic digestion is a very promising solution for the treatment of agricultural waste, preventing pollution and leading to efficient energy production. Since this technology is available to each farmer in a different way depending on the location and the scattering of the primary sources, it is essential to clarify the best conditions adapted to local situations to treat the targeted residues and make this information accessible to farmers. In particular the possibility of codigestion seems to be very attractive for farmers who will be able to treat their own waste together with other organic substrates. Their profit in this case is double since they treat properly their own residues, taking advantage of the selling of heat and electricity as well as the utilisation of a stabilised biofertiliser. The aim of this paper is to present an investment decision kit for economic evaluation of biogas plant projects based on agricultural feedstocks.
226 citations
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TL;DR: The anaerobic digestion process and its complexities are reviewed, the substrate used in the process, the relationship between the substrate and microorganisms and important operating parameters such as pH, temperature and loading rate are covered.
Abstract: The search for alternative energy and fuels has motivated researchers to focus on renewable and sustainable means of getting them instead of relying on the conventional way of energy and fuel production. Anaerobic digestion is a biochemical process during which complex organic matter is decomposed in absence of oxygen, by various types of anaerobic microorganisms. The process of Anaerobic digestion is appropriate for all waste water treatment systems given that the solid can be introduced to the system at an acceptable concentration. Biogas, the product of anaerobic digestion process is a clean and renewable form of energy which can be a substitute for conventional sources of energy which are causing ecological-environmental problems and at the same time depleting at a faster rate. This paper reviews the anaerobic digestion process and its complexities; it covers different stages involved in the process, the substrate used in the process, the relationship between the substrate and microorganisms and important operating parameters such as pH, temperature and loading rate.
225 citations
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TL;DR: The chemical oxygen demand (COD) elimination reached 95.3% demonstrating that cheese whey could be efficiently used for hydrogen and methane production, in a two-stage process.
225 citations