Gasifier Technology

Gasification is a process that converts carbonaceous materials, such as coal, petroleum, petroleum coke or biomass, into carbon monoxide and hydrogen.

In a gasifier, the carbonaceous material undergoes three processes:

Pyrolysis of carbonaceous fuels. The pyrolysis (or devolatilization) process occurs as the carbonaceous particle heats up. Volatiles are released and char is produced.

The combustion process occurs as the volatile products and some of the char reacts with oxygen to form carbon dioxide and carbon monoxide, which provides heat for the subsequent gasification reactions. Pyrolysis and combustion are very rapid processes.

Gasification of char. The gasification process occurs as the char reacts with carbon dioxide and steam to produce carbon monoxide and hydrogen.

The resulting gas is called producer gas or syngas (or wood gas when fueled by wood). In some cases producer gas may be more efficiently converted to energy than would be by direct combustion of the fuel. For example, when the fuel is first combusted in a gas turbine and the heat is used to produce steam to drive a steam turbine. Gasification relies on chemical processes at elevated temperatures >700°C, contrary to biological processes such as anaerobic fermentation (digestion) which produces biogas.

The heat of combustion of producer gas is rather low compared to other fuels. Producer gas has a lower heating value of about 6 MJ/kg versus 55.9 MJ/kg for natural gas and 44.1 MJ/kg for gasoline. A wood gasifier takes wood chips, sawdust, charcoal, coal or similar materials as fuel and burns these incompletely in a fire box, producing solid ashes and soot (which have to be removed periodically from the gasifier and constantly from the gas) and wood gas. The wood gas can then be filtered for tars and soot/ash particles, cooled and directed to e.g. an internal combustion engine, gas turbine, Stirling engine or fuel cell to produce electricity. Most of these devices have severe requirements to the purity of the wood gas, so the gas often has to pass through extensive gas cleaning in order to remove or convert (to "crack") tars and particles.

RANGE OF APPLICATION

THERMAL

POWER

1)   Dryers

1)   Captive Power

2)   Hot Air Generator

2)   Grid Feeding

3)   Kilns / Furnaces

3)   Village Electrification

4)   Ovens

4)   Irrigation / Pumping

5)   Thermic Fluid Heaters

5)   Simultaneous Charcoal Production

6)   Boilers etc.

6)   Any Other Power Application

AVAILABLE RATINGS (SINGLE UNIT BASIS)

W SERIES

F SERIES

COMBO SERIES

100% GAS SYSTEMS

Available Ratings:

Available Ratings:

Available Ratings:

Available Ratings:

3 kWe to 850 kWe

40 kWe to 400 kWe

150 kWe to 350 kWe

4 kWe to 425 kWe

15,000 Kcal/hr to

2.20 million Kcal/hr

100,000 Kcal/hr to

840,000 Kcal/hr

375,000 Kcal/hr to

875,000 Kcal/hr

BIOMASS / FEEDSTOCK

W SERIES

F SERIES

1)   Firewood

1)   Rice Husk

2)   Wood Waste

2)   Threshed Mustard Stalks

3)   Branches / Twigs

3)   Soya Dunage etc.

4)   Coconut Shells etc.

Combo Models can use both types with a simple one-day changeover.

Other agricultural residues could be used after proper size reduction, resulting in a minimum bulk density of 125 kg/m³

Proto type testing for specific feedstock can be taken up by the company for a nominal charge.

SALIENT FEATURES

THERMAL

POWER (DUAL FUEL)

POWER (100%)

Typically, a liter of liquid fuel can be saved with only 3 to 4 kg of woody biomass or 5 to 6 kg of rice husk.

Flame temperature of 1200 ⁰C

Full Oil/LPG replacement for applications requiring up to 1000 ⁰C

Higher temperatures through dual fuelling

Replacement of 65-70% diesel in DG sets with Dual Fuelling

Specific fuel consumption of less than 1 kg wood or 1.4 kg rice husk along with up to 90 cc of diesel

Wide turn down ratio

Both W as well as F series systems available

Limited start-up power for a short period

Specific wood consumption of only around 1.3 kg/kWhr

Wide turn down ratio

Excellent variable load response

W mode for stand-alone application and W/F series for Grid Connected Mode