Tushar Jash

Sustainability of decentralized woodfuel-based power plant: an experience in India.

In accordance with the long-term policy objectives of the government of India for rural electrification, an off-grid woodfuel-based power plant for generation of grid quality electricity has been installed in a remote island of West Bengal. The present study focuses on technical performance of the largest biomass gasifier based power plant in India. Sustainability of such a power plant has been reviewed with respect to diesel replacement, fuelwood supply, cost of electricity generation and pollution load.

Studies on the solubilization kinetics of solid organic residues during anaerobic biomethanation

The solubilization rates of some organic residues during anaerobic biomethanation have been studied and rate equations developed. The effects of selected variables on the solubilization rate have been determined.

Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor

Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m3kg-1VS, at OLR of 1.11-1.585kgm-3d-1, were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation.

Development of a mini-biogas digester for lighting in India

The majority of rural people in India depend on inefficient kerosene lamps for domestic lighting. A mini-biogas digester for small family units, exclusively for lighting purposes, has been designed, developed and installed in field trials.

Performance analysis of micro turbine-based grid-connected biogas power plant in Purulia in West Bengal, India

A micro turbine-based biogas power plant has been generating electricity in Purulia in West Bengal, India since 2007. The present study reports on technical performance of the Purulia biogas power plant for the period since the inception of operation. The performance analysis revealed less than acceptable operational standard of the power project. The reasons behind low power generation rate were identified, and recommendations made to improve the efficiency of the power plant.

Environmental consequences of parallel marketing of LPG in India

In 1993, the government of India introduced a parallel marketing system for petroleum products, particularly for liquefied petroleum gas (LPG). LPG, under the parallel marketing system, is distributed at higher price without any subsidy. The government distributors, however, distribute LPG at subsidized rate. The consumers who get LPG at higher price, therefore, opt for a mixed energy use. The present study, based on a field survey, deals with the pattern of this mixed energy use and its environmental consequences.

Studies on residence time distribution in cylindrical and rectangular biogas digesters

Flow path and stagnant regions inside unheated cylindrical and rectangular biogas digesters have been investigated by using mechanical tracers. The residence-time distributions in cylindrical and rectangular biogas digesters, with and without the use of a stirrer, have been estimated by using both impulse and step inputs.

Loss of fertilizer and fuel value of dung cake

The losses in India in fertilizer and fuel values during the period 1973–1977 are estimated. These have resulted from increasing direct use of dung-cake as fuel.