Biomass is organic material, which has
stored solar energy from sunlight in the form of chemical in the plants through
the process called photosynthesis. Biomass fuels include Agricultural Wastes,
Crop Residues, Wood, Woody Waste & Organic wastes etc. It also includes
biomass like Julifora Prosopis, Casuarinas, Eucalyptus, Acacia, and Subabool as
main feedstock and agro wastes like Tapioca Stalks, Ground nut shell, Coconut
Shells, Sugarcane Trash, Corn Stalks etc. Unlike fossil fuels Biomass does not
add carbon dioxide to the atmosphere as it absorbs the same amount of carbon
while growing. It is the cheapest, eco-friendly, renewable source of energy.
Biomass Gasification converts solid
biomass into more convenient gaseous form. Normally, the ratio of air to fuel
required for the complete combustion of the biomass is 6:1 to 6.5:1, which
defined as stoichiometric combustion with the end products being CO2 and H2O.
In gasification the combustion is carried at substoichiometric conditions with
air-to-fuel ratio being 1.5:1 to 1.8:1. The gas so obtained is called producer
gas, which is combustible having a calorific value of 4.5-5.0 MJ/Kg, with an
average composition of CO : 20 + 1%; CH4 :3 + 1%, H2 : 20 + 1%, CO2 : 12 + 1%
and the rest being N2. This process is made possible in a device called
gasifier. A gasifier system mainly comprises of a reactor, where the
combustible gas is generated and the gas is made available for power
generation/thermal application after the required cleaning and cooling process.
The producer gas generated from Biomass gasifier can be used to
run the diesel engine. The diesel engine needs around 20 to 25% diesel. Now a
days diesel engine in certain capacity are available which can be run on
producer gas. Gasifier when connected with electric generator through engine
can generate electricity. The producer gas can also be used for thermal
application. Burning of 1 cubic meter gas will generate thermal energy of the
order of 4.5 to 5.0 MJ. Flame temperature as high as 12000C can be obtained by
optimal pre-mixing of air with producer gas. For processes, which require
thermal energy, gasifiers can be a good option as a gas generator, and
retrofitted with existing devices. Few of the applications where retrofit is
possible are: Dryers, Kilns, Fumaces, Boilers etc.
Remote, non-accessible villages where laying of transmission lines is not
economical and where sufficient biomass is available, their electrification can
be done through biomass gasifier systems. 1Kg. of biomass can produce 1 unit of
electricity. In case of thermal application thermal energy generated from 4kg.
of biomass is equivalent to thermal energy generated from 1kg. of furnace oil
or diesel. The approximate cost of gasifier for thermal application is Rs.
30000 per kW and for electricity generation the cost is Rs. 1-1.5 lakh per kW.
The capital subsidy from MNES, New Delhi is as follows:
1. Rs. 2.0 lakh / 300 kWth for thermal application.
2. Rs. 2.5 lakh / 100 kWe for electrical application through dual fuel engine.
3. The capital subsidy for biomass gasifier coupled with 100% producer gas
engine in industry is as under –
Rs. 10 lakh / 100 kWe for 100% producer gas engine with gasifier system.
Rs. 8 lakh /100 kWe for 100% producer gas engine alone.
4. The capital subsidy for biomass gasifier with 100 % producer gas engines in
Institutions like engineering/ medical colleges and religious / charitable
institutions working purely on non-profit basis and not registered under
Companies Act will also be eligible for subsidy. Institutions that have already
set up gasifier system with 100% producer gas engine under SADP programme will
not be eligible under this scheme.
5. The capital subsidy for institutional gasifier systems would be as follows :
Rs. 15.00 lakhs per 100 KWe for 100% producer gas engine coupled with gasifier
Rs. 10.00 lakhs per 100 KWe for 100% producer gas engine alone.
This improves rural economy and employment through biomass supply.
The plant will also encourage the concept of energy plantation thus resulting
in greener environment resulting in more rainfall and reduction in ambient
Sustainability by producing industrial grade electricity from renewable