General Information about- Gasifiers and Stoves : Research at IISc

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From: gayathri@aero.iisc.ernet.in (Gayathri)

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We are involved in the field of biomass combustion and gasification research for over one and half decades, during this course we have developed few energy efficient biomass based technologies which are aimed for rural applications. One among them is the fuel efficient stoves for cooking purpose (1 to 4 kW). Under stoves we have two types one for woody (solid) form biomass and the other for powder form like saw dust etc. These are fuel efficient stoves with efficiencies over 30 - 35% (measured in field conditions). It is also possible to design large power level combustors depending on the client’s requirement.

We also developed gasifiers for thermal and power generation application. Here again we have two types depending on the type of biomass. One being woody biomass gasifier which can cater to solid kinds of biomass like wood chips, corn corbs, coconut shells, weeds like julifora prosopis, ipomia and any biomass whose bulk density is over 250 kg/m3. The producer gas generated from the gasifier can be used to operate a normal existing diesel engine in dual-fuel mode and save diesel up to an extent of 80-85%. The consumption of wood being 1kg per unit electricity generated. The same gasifier can also be used for thermal application with flame temperatures reaching up to 1300 0C. A wood gasifier plant for power generation includes a reactor, cooler, cleaning unit and diesel generator set, where as a thermal plant is with out cooling system and D-G set. This technology has been adequately tested at the field level over a period of 8 years and the feed backs incorporated. The wood gasifier is currently available at power levels of 3.75/20/100 kWe or 20/80/400 kWth (also higher power level could be designed) and the technology has been transferred to a private company based at Bangalore.

The other technology pertains to gasification of agro residues like rice husk, rice straw, bagassse, sugar cane trash, coir pith, saw dust etc. This called for a cyclone gasifier and the principle of working is quite different from the wood gasifier. The system is in the advanced stages of testing at the laboratory and shall be deployed on field in less than a year. The system is basically designed to operate on multi-fuels depending on the local availability without being restricted to any single fuel. It is possible to build this system from few kWs to MWs level. The producer gas from this can be similarly used for power/ thermal application. Typically the consumption of rice husk is about 1.5 to 1.6 kg per unit electricity generation. We have also designed a process to recover precipitated silica (99.9% pure) from rice husk char (a residue of gasification of rice husk). Currently these technologies are at the advanced stages of testing and technology not transferred.

Please feel free to communicate any specific queries with information like type of biomass available locally and end use details.

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	Gayathri V
	Project Engineer
	Combustion Gasification and Propulsion Lab.
	Dept. of Aerospace Engineering
	IISc . Bangalore 560 012	Phone :(off) +91-80-3092338 or 3348536
					       (Res) +91-80-6632717
					    	Fax  +91-80-3341683	
	E-mail : gayathri@aero.iisc.ernet.in

	"There is nothing like impossible"
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