Background

Fuelwood continues to play an important role both in domestic and industrial sector in India as it is an agriculture based country. The share of fuelwood in fuel consumption shows declining trends mainly due to the increasing usage of fossil fuels for economic development during the last few year. However, the actual usage in absolute term has increased considerably. Fuelwood fired traditional cooking systems are generally used for large scale cooking, specially in community kitchens such as in marriage halls, schools, hostels, temples, etc. Huge quantities of fuelwood is being used in traditional ovens which normally operate with very low thermal efficiency of 5-15%. This results in tremendous wastage and is one of the key reasons of rapid deforestation.

Commercial prototype of gasifier based silk reeling oven

The continuously rising prices of the fossil fuels and their unreliable availability makes it neccessary to shift to biomass fuel. This has resulted in over dependency on biomass fuels, though biomass is considered to be inferior fuel in its present form. This situation calls for development of a biomass based, energy efficient system with better environmental acceptability, economic viability, and good process control. Biomass gasifier system is ideal for such applications as it can offer all these advantage.

Thermal applications of gasifier system in small and rural industries
Biomass fuels play an important role in the Indian economy, as they are the main source of energy to a large number of small, rural, and cottage industries apart from majority of rural households. A majority of these enterprises belongs to the unorganized sector and, hence, information and data on these industries are scarce. These industries provide employment to millions of people and form a very important part of the rural economy. The biomass-consuming industries can be divided into two categories, traditional industries and new or potential industries.

Traditional biomass-based industries are essentially rural cottage and small-scale industries. These industries depend predominantly on biomass fuels such as wood, agricultural residues, and animal dung because it is cheap and its supply is assured. Biomass energy is used in these industries for direct heating (firing of bricks, lime), indirect firing (drying, baking), boiling, steam raising, and distillation.

New or potential biomass-based industries include many medium-and small-sized enterprises that currently use fossil fuels and are willing to switch over, partially or fully, to biomass fuels available locally at lower prices. Examples of these industries include textile mills, brick kilns, mini cement plants, and lime kilns.

TERI has been involved in several projects to improve thermal efficiency of biomass used in several of these industries both under TERI-SDC (Swiss Agency for Development and Cooperation) partnership projects as well other projects sponsored by various government and private agencies.