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A long-term feasibility analysis of a 100 ton per day mechanical biological treatment (MBT) plant for municipal solid waste (MSW) valorization and material and energy recovery was carried out. It involves the material recovery and segregation stage (MRSS), organic extraction (pulping), thermophilic anaerobic digestion (AD), composting, effluent treatment plant (ETP), and biogas genset stages producing: 11.90% recyclables, 33% refused derived fuel (RDF), 5% compost of total waste received, 70 m3/day recyclable water and 0.435 MWh/day electricity. The biogas and methane yield were 0.535 and 0.350 m3/kg VS added (avg.), respectively, with 40% VS removal (avg total solids (TS) 10%). Less than 3% (inert) of total waste received was subjected to landfill disposal. The MBT plant's revenue generation is 995 US$ per day/148 tons ($ 6.72/ton) waste processed. The gross OPEX is 24 US$/ton making the net OPEX of 17 US$/ton (minus revenue), which could be considered as the excellent OPEX for MSW based MBT plants as per global benchmarks. Further, local usage of RDF can significantly reduce the OPEX to 14 US$/ton, as almost 16% of the OPEX goes towards RDF disposal to cement companies located at a distance of 200–500 km from the MBT plant site. As per LCA study, the total GHG emissions have been calculated to be −25.68 tons CO 2 eq./100 tons MSW. The negative emissions result from the export of electricity, compost, and RDF as well as recycling of paper and plastic products. Our study presents a cutting-edge scenario of all-inclusive recycling, recovery, and reuse loop of MSW direly required for accomplishing a circular economy. [Display omitted] • Long term performance of first successful 100 tons/d MBT plant in India was studied. • 12% recyclable, 33% RDF, 0.435 MWh/d power, 5% compost, 70 m3/d water were recovered. • Biogas and methane yield were 0.535 and 0.350 m3/kgVS added (65%CH 4), 40%VS removal. • MBT plant has OPEX of US$ 24/ton and revenue of $6.72/ton; net OPEX of US$ 17/ton. • LCA study revealed the negative GHG emission of −41.45 tons CO 2 eq./100 tons MSW. [ABSTRACT FROM AUTHOR]

Growing organic waste in India is posing a challenge in its effective management. Open degradation of this organic waste pollutes environment, as well as causes a slew of diseases. Situation may be handled effectively using biogas plants employing anaerobic digestion process. However, performance of these plants is dependent upon various environmental factors and feed types. In this paper, the feasibility analysis of a biogas plant for the northern plains of India has been conducted. A new modified anaerobic digestion model (MAD1) has been designed for the analysis. It is evident from the analysis that the northern plains of India have a large potential for biogas production as they generate a large amount of organic waste. Furthermore, analysis reveals that, if the biogas plant is operated at a thermophilic temperature ranging from 44 °C to 55 °C, the profit can be maximised. However, if the biogas plant is operated at 37 °C, the significant profit will begin after 3–4 years, depending on the type of feedstock. Complete analysis has been conducted in MATLAB Simulink environment. • Conducted sensitivity analysis of the parameters of anaerobic digestion process • Conducted feasibility analysis of biogas plant for Northern Indian states. • Conducted economic analysis of biogas plant to maximize profit • Modelled a modified anaerobic digestion model (MAD1) for realistic output [ABSTRACT FROM AUTHOR]

India is an agrarian country producing a large amount of rice straw as an agricultural residue. These residues are burnt openly leading to severe environmental pollution and health hazards. Among several options available, anaerobic digestion of rice straw into biomethane gas and digestate is a promising technology. The current paper reviews the characteristics, principles of rice straw and the process variables (temperature, volatile fatty acids, and pH, carbon to nitrogen ratio, metal elements and organic loading rate) that affect the performance of the rice straw digestion and process strategies which may alleviate the barriers and may improve the biomethane yield. Co-digestion of rice straw with nitrogen-rich substrates is proven to be an effective way to balance the carbon to nitrogen ratio, in turn, leads to nutrient balance and enhance the biomethane yields of anaerobic co-digestion system. Moreover, pretreatment is another effective strategy; physical, chemical and biological pretreatments are reviewed in the article which improved the performance of digester. The utilisation of rice straw along with other co-substrates and appropriate pretreatment may be a recommended sustainable solution for preventing environmental and health hazards. [ABSTRACT FROM AUTHOR]

In India, a significant portion of the population is still dependent on traditional biomass as fuel for household cooking. The combustion of conventional fuel for cooking usually negatively impacts human health and the environment. Biogas can have multiple benefits; it includes saving time to collect firewood, is a clean fuel, and may reduce greenhouse gas emissions. A national program on biogas is implemented in India since the 1980s. However, there is a considerable difference between the potential and its utilization. Also, biogas' emission through leaks and intentional release is regular with poorly maintained digesters, which questions the environmental benefits it might have. This paper assessed the significance of biogas as a cooking fuel. The results show that, if adequately maintained, biogas result in minimum GHGs emissions than other fuel options. However, if not, this will result in a harmful impact on the environment. Furthermore, annually 1181.31 PJ of useful energy is required for cooking in India. However, currently the contribution of biogas is <0.5 %. In addition, it is also found that in the current scenario, overall GWP from household cooking is about 204,479.92 Gg CO 2 eq. If energy from surplus animal dung is harnessed correctly, 321.62 PJ per annum of useful energy can be harnessed. The use of biogas can reduce 20 % of GWP from India's household cooking. Economic analysis shows that installing a biogas digester is an economic viable option with IRR of 54 %. Overall, the use of biogas is beneficial from environmental, resource and economic point of view. • Anaerobic digesters can be a huge source of GHG emissions. • Comparison of biogas' environmental affects with different fuel used for cooking. • Current status of energy supplied and GHG emissions by different fuels in India. • Intervention of biogas can reduce overall GHG emission from household cooking sector. • This study will help government in guiding policy related to small scale biogas plants. [ABSTRACT FROM AUTHOR]

The coir industry in India's southern coastal regions, especially in the state of Kerala, is becoming increasingly concerned about the environmental impact of the accumulation and incremental increase of coir pith each year. The objective of this study was to assess the effect of pretreatment on the anaerobic digestion of coir pith. The characterization study of coir pith shows high organic content, which can be anaerobically digested to produce biogas. But, the high lignin content (30.91%) makes the process slow. To overcome this, a biological pretreatment method was tried using two microbial cultures belonging to fungal genera known to be lignin decomposers, viz., Trichoderma and Pleurotus. By using Trichoderma, lignin content was reduced by 3.7%, and the maximum gas production was obtained in a shorter time (19 days) in comparison with the sample without any pretreatment (24 days). When Pleurotus was used for lignin degradation, the lignin content was reduced by 6.78%, and the maximum gas production was obtained in a much shorter time period (14 days) in comparison with the former two methods. The gas produced comprises 74 ppm of methane, which has fuel value. The sludge after digestion was tested, which indicated a marginal increase in NPK value and hence can be used as fertilizer. The results of the study appear to be quite promising in the transition towards green energy by providing scope for the process of biomethanation, with the conclusion that further research can transform coir pith into a good renewable energy resource. [ABSTRACT FROM AUTHOR]

The application of compressed biogas (CBG) in day-to-day livelihood has garnered significant attention in modern day era. It is considered as a potential solution to curb the increasing energy demand and other environmental concerns. The process involves anaerobic digestion (AD) (hydrolysis, acidogenesis, acetogenesis and methanogenesis) of organic substrate under an optimum operating condition (pH, temperature, etc.) via anaerobic microorganisms. This paper aims to describe some major facts about different technological options related to pre-treatment, AD, cleaning and up-gradation system. It also highlights the practical challenges related to high investment cost, inadequate infrastructure, clearance and approval issues, poor feedstock supply chain management etc. in adaption of CBG plants in India. The review examines the significance of both dry and wet continuous digester systems, which includes its advantages and challenges, considering factors, such as feedstock characteristics, process stability, and operational efficiency. It was also found that the type of feedstock and its availability in existing market plays a vital role in smooth functioning of CBG plants. Therefore, the study presents a comprehensive review discussing potential feedstock readily available for CBG plants in Indian market. It was concluded that the usage of agricultural waste (such as Napier grass) has higher CBG potential compared to other feedstock. At the same time, the study presents a broader aspect to policy makers and governing authorities to reframe the existing structure for financial assistantship, regulatory laws, subsidiary schemes etc. for CBG plant owners. It also gives an opportunity to technocrats, industrialist and investors to come-up with an indigenous technology with in-house manufacturing units to promote CBG production in India. [Display omitted] • India has 46 compressed biogas plants with an overall capacity of 272 tonnes/day. • Elaborated the significance of both dry and wet continuous digester systems. • Setting-up a compressed biogas plants requires high investment and operational cost. • Potential market for bio-fuels and bio-fertilizer needs to be explored in India. • Existing financial assistantship and subsidiary schemes need transformation. [ABSTRACT FROM AUTHOR]

In India, electricity use in rural areas accounts only 23% of national total usage. It is necessary to expand the access to electricity in Rural India for sustainable development. Biomass, a viable resource is the most direct and simple way at households and rural areas. Organic waste can be converted into an alternative source for cooking, heating and electricity. Biogas, a biofuel produced from organic waste (food scraps and animal waste) through Anaerobic Digestion. It is mainly composed of methane and carbon dioxide produced through Anaerobic Digestion in either large scale or small scale digesters. Traditionally, biogas has been used for cooking. Based on village level survey, electrical energy is the only commercial form of energy that has been used in villages. Biogas production paves the way to produce electricity at villages through high temperature fuel cell unit like Solid Oxide Fuel Cell; thus it is the best possible way to generate and utilize power close to where people live. The present paper discusses about the rural energy requirement, overview of biogas production and fuel cells, potential and operational challenges for biogas fed Solid oxide fuel cell, technical barriers with Solid oxide fuel cell and issues related to rural electrification using renewable energy. Also, a comparative analysis of SOFC with bio and thermo chemical conversion of biomass has been analyzed with a case study and reported. • Based on village level survey in a village at Dindigul Dt, Tamilnadu, India, electrical energy is the only commercial form of energy that has been used. • Biogas production paves the way to produce electricity at villages through high temperature fuel cell unit like Solid Oxide Fuel Cell; thus it is the best possible way to generate and utilize power close to where people live. • The present paper discusses about the rural energy requirement, potential and operational challenges for biogas fed Solid oxide fuel cell. • A comparative analysis of SOFC with bio and thermo chemical conversion of biomass has been analyzed with a case study and reported. [ABSTRACT FROM AUTHOR]

In recent years, lignocellulosic biomass has gotten a lot of coverage, especially for the captured energy through the anaerobic degradation. The conversion of lignocellulosic biomass to biogas through an anaerobic digestion process has been facing challenges such as low biogas production, low buffering ability, poor end quality of products, and potential heterogeneity of biomass which have difficulties to define an optimized unit operation. These deficiencies may be related to the recalcitrant disposition of agricultural wastes or low mass transfer. India has a large amount of lignocellulosic biomass, and this biomass remains unused in the harvested field. However, it has a scope of utilization by conversion into useful biofuel. Furthermore, it could be enhanced the farmer's income as well as helps to contribute reduce the loss of environmental impact. Hence, the present review script discusses the potential, composition, biomethane production, pretreatment methods and technology related to lignocellulosic biomass, challenges, progress, and the latest program initiated in India. However, only 10 major types of lignocellulosic biomass have been reviewed in this paper. [Display omitted] • Lignocellulosic biomass has a scope to convert into biofuel. • The conversion of lignocellulosic biomass to biogas facing some challenges. • Pretreatment necessary for conversion of lignocellulosic biomass to biogas. • Out of all the pretreatments, alkali pretreatment (NaOH) is the most promising. • The combination of two or more pretreatments provides a better result. [ABSTRACT FROM AUTHOR]

Abstract: The potential of biogas generation from anaerobic digestion of different waste biomass in India has been studied. Renewable energy from biomass is one of the most efficient and effective options among the various other alternative sources of energy currently available. The anaerobic digestion of biomass requires less capital investment and per unit production cost as compared to other renewable energy sources such as hydro, solar and wind. Further, renewable energy from biomass is available as a domestic resource in the rural areas, which is not subject to world price fluctuations or the supply uncertainties as of imported and conventional fuels. In India, energy demand from various sectors is increased substantially and the energy supply is not in pace with the demand which resulted in a deficit of 11,436MW which is equivalent to 12.6% of peak demand in 2006. The total installed capacity of bioenergy generation till 2007 from solid biomass and waste to energy is about 1227MW against a potential of 25,700MW. The bioenergy potential from municipal solid waste, crop residue and agricultural waste, wastewater sludge, animal manure, industrial waste which includes distilleries, dairy plants, pulp and paper, poultry, slaughter houses, sugar industries is estimated. The total potential of biogas from all the above sources excluding wastewater has been estimated to be 40,734Mm3/year. [Copyright &y& Elsevier]

India is a rapidly growing country and this created pressure on its natural resources. During its growth and development, different types of wastes are produced through agricultural, industrial, and anthropogenic activities besides increase in energy demand to keep its pace of growth to become a developed nation. Various strategies like landfill, incineration, gasification, and anaerobic digestion (AD) are available to treat as well as to produce energy from the wastes. Production of biogas through AD is one of the best available options due to low energy requirement and eco-friendly nature as compared with other methods. In India, waste to the energy sector may project to a market size of 14 billion ~USD by 2025 with an annual increase of around 7%. In order to capture this untapped source of energy scientific management of waste along with Government policies, schemes and incentives for waste management, renewable energy, agriculture, etc. and their implementations are crucial cornerstones for the promotion of biogas technology and to get renewable energy on sustainable basis. But still a number of challenges are being faced by its stakeholders in India to transform wastes into energy and to secure a clean and green future. Production process of gaseous fuels, management of wastes, its logistics, and recent advancements in Govt. policies and schemes are being discussed in this review article that may help its stakeholders to make India self-reliance in renewable energy along with sustainable growth and development. [ABSTRACT FROM AUTHOR]

Agricultural waste generation including 1207 million tonnes (MT) of animal dung and 498 MT of crop residues represents an important source of energy in India. A total of 869 MT of recoverable animal dung and 177 MT of surplus crop residues can produce 54 Billion m3 of biogas under anaerobic codigestion to provide 622 PJ of cooking energy per annum fulfilling a major portion of cooking energy requirement of the country. Analysis reveals that the biogas potential of the country can be enhanced by 50% by application of codigestion technology over single feedstock digestion. Financial viability analysis carried out for the codigestion technology reveals its economic superiority over already existing single feed stock digestion. [ABSTRACT FROM PUBLISHER]

Rural India derives its energy needs for cooking and heating through the use of fuel wood and for lighting and agricultural operations through kerosene and diesel. Use of fuel wood has aggravated the problem of de-forestation, while availability of kerosene and diesel cannot be guaranteed due to corrupt practices in the public distribution systems. In contrast, urban India derives its energy needs through LPG cylinders, petrol, and electricity. However, their cost and uncertainty rendered them beyond the reach of lower income population. This scenario is more or less true with many developing countries. To meet these objectives, biogas generation from biodegradable waste using anaerobic digestion (AD) appears to be a sustainable avenue as it could be used for (a) water and space heating of farmhouses, animal shelters, (b) generating steam for food processing plants, and (c) electricity generation, in addition to reducing the pollution/hazard potential of these wastes. Many of the underdeveloped and developing countries are in the temperate zone and thus mesophilic AD could provide a desired pathway to achieve a long delayed need of energy for comfortable living, farming, and industrial operations. Efforts made in this direction are reviewed in the present article. [ABSTRACT FROM AUTHOR]