Energy is an essential input for economic development and for improving the quality of life. India’s per capita consumption of commercial energy is only one eighth of global average. Industrial countries with only 22% of world’s population produce 54% of total global energy and consume 84% of it. On the other hand, developing countries with 78% of world’s population produce only 46% of total energy and consume just 16% of it. About 2.4 Billon people used the traditional biomass mainly for cooking and heating essentially all of those uses traditional reside in developing countries and most of them lives in rural area. Low income and lack of access to alternative, modern fuel explain their choice of traditional energy supply. About 46% of the total energy consumption of India is through cooking energy. The rapid growth in world population has created manifold rise in energy consumption. The resulting energy shortage necessitated research and development in alternate and local resources.
1.2 Bio- energy utilization
In rural areas for cooking, cookstoves are used generally based on wood. Wood is primary energy source for more than one third of world’s population. In many of these areas 80 to 90% of households depend on wood as primary source of energy. About 70% of wood, which is cut in the forest used only for cooking purpose in rural areas. Approximately 150 million of wood is burnt for cooking every year in India. It is therefore necessary to conserve cooking energy by every possible means.
1.3 Fuel and their types
What is fuel?
Any source of heat energy is called fuel. The term “Fuel” includes all combustible substances that combine with oxygen from the atmosphere with the evolution of large amount of heat capable of being economically applied to domestic and industrial purpose.
Types of fuel -
There are three types of fuels: -
1. Solid fuel- It includes coal, charcoal, wood, etc.
2. Liquid fuel — Petrol, Kerosene, etc.
3. Gaseous fuel — Coke - oven gas, producer gas, semi coal gas, etc.
Calorific value -
Calorific value may be defined as that amount of heat liberated in calories to complete combustion of combustible material with oxygen and consideration of product to the desired temperature criteria of selection of wood.
The following factors were taken into account while selecting the fuel:
i. Suitability to process - The fuel taken for combustion should be suitable to process example for foundry fuel. ii. Supply position — Supply position with regard to availability in sufficient quantity should be considered. iii. Cost of fuel — The fuel should have low cost and should not change its property accordingly to long storage. iv. Calorific value - Calorific value of fuel should be high.
Wood — Wood is a solid fuel. In India the chief fuel that is available in large quantity is wood. It consists of cellulose (C6H1o05), lignin, resins, inorganic materials and 60% water.
The water content of wood varies from 25% to 60% depending upon its condition whether it is dried or freshly cut. Composition of dry wood is as follows: Carbon C = 50 %
Oxygen O2 = 34 %
Nitrogen N2 = 7 %
Hydrogen H2 = 6 %
Ash = 2 %
The calorific value of wood ranges between 3000 - 6000 kcal/kg.
1.4 Improved Cookstoves
The traditional chulhas commonly used at present in rural areas have low thermal efficiency. About 7 to 10% of the energy in wood is utilized in the cooking process and consequently consume more fuel besides emitting a lot of smoke. This causes indoor air pollution to which women and young children are exposed; it consumes more time for cooking and hazardous as sparks can cause fire to thatched roof.
In the earlier time after discovery of fire, the people did not have knowledge about cookstove and they used three stones putting in...