Biomass Gasification Technology is an eco-friendly alternate energy source that can help organizations gain a competitive advantage. In fact, gasification is the cleanest, most efficient combustion method known. Biomass gasification is the process of conversion of solid biomass into gaseous form. In simple terms, this uses the easily available biomass and converts it into energy.

AHE uses a unique downdraught gasifier with unique feature of open top with twin air entry system. This was specially developed by Advanced Bio Residue Energy Technologies Society (ABETS), which is part of the Combustion Gasification and Propulsion Lab (CGPL), Department of Aerospace, Indian Institute of Science, Bangalore. AHE is a licensed user of this Technology.

The Process of Gasification

The process of gasification consists of partial Pyrolysis, Oxidation, and reduction under sub-stochoiomatric conditions. This generates producer gas, which contains H2, CO, CH4, CO2 and N2. This raw and hot producer gas contains particles of dust and condensable compounds, termed tar, both of which should be restricted to less than 15 ppm each, for the gas to be used in the internal combustion engine. The producer gas is cleaned and coded to ambient temperature for meeting thermal needs and power generation.

Components of the Gasifier Plant

AHE provides an integrated plant with biomass processor, waste heat drier, biomass gasification system, power package and effluent treatment plant. The following are the components.

• Material handling system for conveying biomass into reactor.
• Gasifier Reactor (Stainless steel and ceramic lining inside) which generates producer gas.
• Cooling, scrubbing and cleaning system, which help to clean and cool the producer gas to ambient temperature, prior to admission to burners for thermal application or into IC engines for power generation
• Water Treatment (water can be cooled, recycled and used after chemical treatment)
• Control room (MCC, PLC instrument panel and operating control desk)

Features

• Open top, twin air entry system, which ensures a better thermal environment compared to the conventional closed top model. Uses Unique staged air injection.
• Multi-fuel capability - wood residues and agro residues in briquetted form with moisture content less than 12%.
• Permits high gasification efficiency above 85%, with biomass consumption between 1.1 kg to 1.2 kg/KWH.
• Producer gas generated is of a very high quality. It is environmentally sound (CO₂ neutral) with low Nox and no Sox in the engine exhaust.
• The gasifier is robust in construction with ceramic lining inside for a better operating atmosphere and considerably reduces gasifier maintenance.
• Reactor design with a ceramic inner shell - diameter and stages of air injection and associated details are tuned to provide a thermal and chemical environment to crack tar molecules to simpler compounds.
• Procedures and designs to harness the waste heat available from engine exhaust and engine cooling water for other heating and cooling applications.
• In-built safety features that isolate the gasifier in case of an emergency shut down.
• Effective gas cleaning system which provides gas with less than 15 ppm of suspended matter to meet quality standards set by engine manufacturers.
• Eligible for benefits under CDM.

The AHE Edge

AHE gives its clients the assurance of complete quality. (It has been rigorously tested and uses durable material that will withstand tough work conditions.) This is an industrialized system where the reactor is built with high Alumina ceramics to withstand the thermal and corrosive environment and so requires only the minimum of maintenance. The unique staged air injection it uses is not adopted by any other gasification Technology in the World.

This is the only design where rigorous tests have been performed over a wide range of fuels and on systems for as large as 1100 kg/hr. It is the only fixed bed design where the long term field performance data of at least six large industrial systems have been tracked and valuable user related data on long term operation and maintenance costs have been collated.

AHE has partnered with Cummins, a leading global manufacturer of small and large engines and evaluated the field performance of engines. The quality of the gas generated is established in rigorous tests in India and overseas to meet European test requirements through third party inspection and independent laboratory tests. The system generates ultra clean gas with tar and particulate matter less than 4 ppm in the cold gas prior to the entry to the engine.

AHE’s Technology is the only design with institutional support for long term follow up and problem resolution.