Replacement of Liquid Petroleum fuels i.e. HSD, LDO, TO, FO etc for Heat / Thermal Energy Generator. We developed commercial sized GEL Wood Base Thermal / Heat Energy System for generation of electrical power as well as thermal energy from agro waste. Upto 500 KW electrical power or upto @ 1.25 million Kcal/hr. thermal energy can be produced by a single reactor and more in megawatts can be done by a battery of units.

In GEL system, solid biomass – a carbonaceous fuel is burnt under controlled air and water to produce a combustible (carbon – monoxide based) gas, generally known as producer gas. This gas is having calorific value of 1200 – 1250 Kcal/nM3 which is being utilized for generation of electrical power and /or thermal energy. However, before any use of this gas, it is important to clean and cool the gas as it contains tar and other impurities.

In our system, solid agro-waste/forest waste (which is termed as Biomass) is converted to a combustible gas by thermo chemical process. The gas thus produced is cleaned and cooled thoroughly before any use for generation of electrical power or thermal energy. To generate electricity the gas is either introduced to a diesel genset (CI engine) to run on 70-75% gas and 25-30% diesel oil or to any gas genset (SI engine) to run on 100% gas. In the process uninterrupted quality power can be generated at a low cost. Further, since the gas is combustible in nature, the same can also be fired with the help of a suitable burner and temperature upto 900⁰ C - 1000 ⁰ C can be achieved.

Since producer gas is combustible in nature, the same can be fired with the help of a suitably designed burner. This is how boiler, furnace, oven etc. can be gas fired to replace oil, coal or any other costly fuel. In this case, there will be no ash/fly ash or particulate in the exhaust gas.

Again, temperature upto 900⁰ C can be achieved by burning of the above gas. Hence, process heat for industrial applications namely, heating of water, air, fluid etc. is obtained from producer gas at the cheaper cost.

The Gasification process technology is based on production of a highly combustible gas by controlled reactions of Biomass viz. wood, wood waste etc. with air and water vapour.

In the system the solid biomass fuel having moisture content not exceeding 20% and 25mm size is fed from the top, while the air and steam is fed from the bottom, and moves upward against the downward movement of the biomass fuel, and this process of gas generation is called Updraft principle.

A number of chain chemical reactions are believed to take place in the gas generator from the bottom to the top, a proper mixture of air water vapour pass through channel free compact fuel bed ensuring the following reactions to take place.

Oxidation Zone C + O2 = CO2 + Heat

Primary Reduction Zone C + CO2 = 2CO ~ Heat C + H2O = CO + H2 ~ Heat C + 2H2O = CO2 + 2H2 ~ Heat

Secondary Reduction Zone C + CO2 = 2CO ~ Heat CO + H2O = CO2 + H2 ~ Heat

While the plant is under normal operation, following zones are believed to exist in the reactor, as shown in the cross sectional view below :  

( A ) Ash Zone
An exchange of heat takes place from hot ash to the entering air and water vapour and thus the hot process air enters the oxidation zone and the cooled ash leaves the system at the bottom to the water seal, generally maintained at about 600 m.m.w.g.

( B ) Oxidation Zone
It is a thin zone having the highest temperature (950⁰C – 1100⁰C) in the reactor due to the exothermic reaction.

( C ) Primary Reduction Zone
The heat released by the oxidation zone below is cooled down by the endothermic reactions in this zone with the formation of CO, H2 and CO2 by the interaction of C present in the fuel with O2 and H2O present in the process air.

( D ) Secondary Reduction Zone
It reduces further the temperature of the gas coming out of the zone below it due to the endothermic reactions with the production of CO by the interaction of C with CO2 and simultaneous water gas reaction.

( E ) Distillation Zone
The heat of the up moving gas from the secondary reduction zone helps the distillation of the volatile matters present in the fuel with the evolution of high volatile hydrocarbons which combine with the gas to enrich it in its calorific value and the temperature of the gas goes down further.

Though for different biomass fuels, there may be little variation in gas composition as well as the heating value, the gas composition and calorific value in general are as follows :

CO2 = 8 ~ 10% O2 = Less than 1.0%

CO = 24 ~ 26% CH4 = 1.5 ~ 2%

N2 = 54 ~ 56% H2 = 10 ~ 12%

CV. (Gorss) = 1200 ~ 1250 K.cal / Normal cubic meter.
Sp. Gravity = 0.92
Yield of Gas = 1.70 ~ 1.90 Normal cubic meter per kg. of biomass.

GEL Wood Therm Plants are already in use for considerable period of time for power generation as well as for various industrial thermal applications, viz. firing of boiler, tunnel kiln, chemical furnace, thermid fluid heater, bakery oven, food grain dryer etc.  

GEL Plants are highly economically viable in Bakery industries, where oil is presently used for baking of bread. 5 kgs. of wood or 6 kgs. of rice husk (moisture content not exceeding 20%) can replace a litre of oil.

Specific advantages of GEL Wood Base Thermal / Heat Energy Systems are highlighted below for ready reference :-

( A ) Continuous Operation
GEL Wood Therm Plants is designed for continuous operation of 24 hours a day and at least upto 350 days at a stretch, after which a brief shut down of 15 days is recommended for annual maintenance. The plant may again be put to operation there after. On-line stand-by for all mechanical items like blower, motor, pump etc. are provided for this purpose.  

( B ) Higher Flexibility
It is a multi-fuel system. The plant can run with any one of the biomasses from a wide range, whichever available locally. Beside rice husk, the same plant may also run with wood block, saw dust, wood bark, sun flower seed husk, ground nut shell, coconut shell, corn cob etc.

( C ) Unique Gas Cleaning System
GEL Wood Therm Plants is coupled with a unique Gas Cleaning System to clean and cool the gas in TEN STAGES to ensure virtually tar-free gas for the engine.  

( D ) Uninterrupted Power Supply
The modified diesel generating set, which normally runs with dual fuel i.e. gas and diesel oil, can also run with 100% diesel oil in absence of gas just by changing a knob. Hence, uninterrupted power supply is assured even when plant is shut down for any reason.

( E ) Low Cost Power
The capital investment as well as the cost for generation of power are very low in comparison to any other system.

( F ) True value for Investment
Great care has been taken for plant for safety and longer life; GEL Wood Therm Plants is designed to have a life of at least 15 years.