::Biomass Gasifier::

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 –

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 :

Social Benefits:

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 temperature.
Sustainability by producing industrial grade electricity from renewable sources.