Biomass is organic material that comes from plants and animals, and it is a renewable source of energy. Biomass contains stored energy from the sun. Plants absorb the sun’s energy in a process called photosynthesis. When biomass is burned, the chemical energy in biomass is released as heat. Biomass can be burned directly or converted to liquid biofuels or biogas that can be burned as fuels. Examples of biomass and their uses for energy are:
- Wood and wood processing wastes—burned to heat buildings, to produce process heat in industry, and to generate electricity
- Agricultural crops and waste materials—burned as a fuel or converted to liquid biofuels
- Food, yard, and wood waste in garbage—burned to generate electricity in power plants or converted to biogas in landfills
- Animal manure and human sewage—converted to biogas, which can be burned as a fuel
Burning is one way to release the energy in biomass. Itcan be converted to other useable forms of energy such as methane gas or transportation fuels such as ethanol and biodiesel. Methane gas is a component of landfill gas or biogas that forms when garbage, agricultural waste, and human waste decompose in landfills or in special containers called digesters. Crops such as corn and sugar cane are fermented to produce fuel ethanol for use in vehicles. Biodiesel, another transportation fuel, is produced from vegetable oils and animal fats.
The current availability of biomass in India is estimated at about 500 million metric tons per year. Studies sponsored by the Ministry has estimated surplus biomass availability at about 120 – 150 million metric tons per annum covering agricultural and forestry residues corresponding to a potential of about 18,000 MW. This apart, about 7000 MW additional power could be generated through baggasse based cogeneration in the country’s 550 Sugar mills, if these sugar mills were to adopt technically and economically optimal levels of cogeneration for extracting power from the bagasse produced by them.
About 32% of the total primary energy use in the country is still derived from biomass and more than 70% of the country’s population depends upon it for its energy needs. Biomass power generation in India is an industry that attracts investments of over Rs.600 crores every year, generating more than 5000 million units of electricity and yearly employment of more than 10 million man-days in the rural areas. For efficient utilization of biomass, bagasse based cogeneration in sugar mills and biomass power generation have been taken up under biomass power and cogeneration programme.
Bio Energy Research
Various aspects of bioenergy sector are being researched by various research institutions, IITs and universities. The spectrum of research is very broad from development of biomass using molecular and synthetic biology approach to assessing biofuels for vehicles. Research on analysis and development of policies is also being carried out at some institutes. Thus there is ample scope for technology development and hope for finding integrated solutions to the complex challenges that the field faces.
Biomass Energy Conversion
There are some agencies and industries practicing the conversion of different biomass waste to energy in India and reported huge benefits from these. This clearly shows the enormous potential of conversion of various biomass wastes to energy in Indian scenario.
Many of these technologies have profitably been implemented and are being used by industries by in-house energy saving, which increases their profits. Similar industries are adapting these technologies with the help of various government agencies e.g. MNRE (formerly known as MNES), academic institutions like Indian Institute of Science (IISc) and Indian Institutes of Technology (IITs), as well as certain non-government organizations.
There is large scope exists for the exploitation of bio-crops for their conversion to bio-fuels e.g. ethanol and bio-diesel, by thermo conversion as well as bio-chemical conversion routes. Apart from these energy crops, a huge potential exists for energy generation from the various industrial wastewaters by bio-chemical routes. Similarly other biomass wastes e.g. wood wastes, crop residues, animal manures, and municipal wastes also bear a large potential for energy generation using bio-chemical as well as
Thus biomass conversion to energy and fuels may be a quite rewarding in Indian scenario. India has high potential of biomass about 500 metric tons per year availability. As per MNRE around 17,500 MW power can be generated by this available biomass and additional power about 5000 MW can be produce by surplus available biomass which is around 120–150 MT. This surplus biomass can be collected from waste of various industries such as baggase in sugar mills. As on today around 550 sugar mills are available in India. Based on existing combustion technology in biomass, 4.5 EJ (105 Mtoe) of direct heat from the industrial and residential sectors, and 2 to 3 EJ (47 to 70 Mtoe) of heat from combined heat and power (CHP) plants are obtained. As per MNRE, it is expected that 73,000 MW energy will be produce by 2032 using biomass as well as baggase cogeneration.
It is clear from the potential of biomass in India that various feedstocks are available for conversion to the bio-fuels as well as for power generation applications. The variety of processes exists for biomass conversions are depends on the type and quantity of biomass feedstock, environment and economic conditions etc. Conversion of biomass to energy is undertaken using two main process technologies: thermo-chemical and bio-chemical/biological. Mechanical extraction (with esterification) is the third technology for producing energy from biomass, e.g. rapeseed methyl ester (RME) bio-diesel. The thermal conversion processes consist of pyrolysis, biomass gasification, combustion and liquefaction.
MNRE has installed 130 biomass power projects this is total aggregate to 999.0 MW and 158 bagasse cogeneration projects in sugar mills with additional capacity which aggregate to 1666.0 MW power to feed the grid. In addition, around 30 biomass power projects aggregating to about 350 MW are under various stages of execution. Approximately 70 Cogeneration projects are under implementation with surplus capacity aggregating to 800 MW . The contribution of bio-energy to the total primary energy consumption in India is over 27%, mainly because biomass is used in a significant way in rural areas.
In the 12th five year plan period the Government is allocating a total of Rs. 46.00 crores for biomass Gasifier schemes which include promotional and other administrative activities. Programs implementation during 12th five year plan period has included the following components: – Off-grid/distributed power program based on Biomass Gasifier, to be implemented for rural areas to fill the unmet demand of electricity. – 100% engines based on producer gas are supported at MW level in Biomass gasifier based grid connected power program. – Boiler Turbine Generator (BTG) based on biomass, would be supported with maximum acceptable capacity of 2 MW. – Programs also cover promotional activities, publicity, seminars/ training programs etc. Indian Government providing many types of subsidies for promoting the growth of bio power market. They are making various patterns to attract investors in the bio power market, in both types of schemes i.e. off grid and on grid. MNRE is providing various types of subsidies for both the private and government sectors.