BIO-GAS AS ONE OF THE MAJOR ALTERNATE RENEWABLE SOURCES OF THE PROVISION OF ENERGY

It is very evident today that no single source of energy would be capable of replacing fossil oil completely which has diverse applications. However, the dependence on fossil oil would have to be reduced at a faster pace so as to stretch its use for longer period and in critical sectors till some appropriate alternative energy sources preferably renewable ones are then made available. Methane gas which are popularly known as bio-gas is one such alternate sources of energy which has been identified as a useful hydro-carbon with combustible qualities as that of other hydrocarbons.  

Bio-Gas, its production process and its mixture

Bio-gas:  Bio-gas mainly comprises of hydro-carbon which is combustible such as hydro-carbons and can produce heat and energy when burnt. The chemical formula of the hydro-carbon is giving as CH4 where C is carbon and H for hydrogen and chemically the gas is termed as methane gas. Methane gas is renewable through continuous feeding of biological wastes and they are available in rural areas. Since the useful gas originates from biological process, it has been termed as bio-gas in which methane gas is the main constituent of it.

Production Process: The process of bio-gas production is anaerobic in its nature and this takes place in two stages. The two stages have been termed as acid formation stage as well as methane formation stage. In the acid formation stage, the bio-degradable complex organic compounds of solids and cellulose presents in the waste materials are acted upon by a group of acid forming bacteria which are present in the dung and reduce them into organic acids, CO2, H2, NH4 and H2S. Since the organic acids are the main products in this stage, it is called acid forming stage and this serves as the substrates for the production of methane by methanogenic bacteria, while the second stage, groups of methanogenic bacteria which act upon the organic acids produces methane gas and also reduce water in the presence of H2 to form methane. At the end of this process the amount of oxygen which demands materials in the waste product is reduced to safe level for handling by human beings.

Scope of Bio-Gas in plants

The basic feed material for bio-gas plants has been considered to be cattle dung which is available in plenty. Cattle dung has been recognized as the chief raw material for bio-gas plants, other materials like night-soil, poultry litter and agricultural wastes are also used where they are socially acceptable. In addition to combustible gas, the bio-gas plants would also be a source for conserving organic manure which is very rich in NPK. In bio-gas plant, it is estimated that recoverable dung from 240 million cattle can add about 3.5 million tonnes of Nitrogen to the soil every year and for ensuring its conservation bio-gas plants can be very useful.

The major advantages of installing bio-gas plants

Alternative sources of energy like bio-gas plants, wind mills and so on, may reduce the dependence on conventional sources of energy by about 20%, provided promotional efforts are continued. The cooking media in rural areas consist of burning dung cake, fire-wood and to some extent kerosene where it is available easily. The installation of bio-gas plants would directly replace the use of the above three and in saving them, following benefit would be achieve;

Nearly 30% of available dung which is burnt and wasted would be recovered as bio-gas plants conserve the dung while producing bio-gas. In addition, the dung after digestion in gas plant preserves more of NPK in the dung solids and cellulose which otherwise gets lost if heaped in the open.

The second major advantage is that rural people would gradually stop felling trees. Tree felling bas been identified as one of the major causes of soil erosion and it worsening flood situation. Continued deforestation has been causing ecological imbalances in the environment in which we live. Bio-gas plants would be helpful in correcting this.

Thirdly, in the rural areas, kerosene is used for lighting lantern and cooking in a limited way wherever kerosene supply has been made possible. Whatever quantity is used can be replaced by bio-gas as it can be used for lighting and cooking.

Finally, the most important social benefit would be that the dung being digested in the digester, there would be no open heap of dung to attract flies around, insects and infections. Also, gas cooking would remove all the health hazards caused by dung cake or fire wood cooking and would keep the women folk free from respiratory and eye diseases  which are prevalent in the rural areas.