The system produces coal gas in two stages.
The UPSTAGE GAS is produced when the coal in the gasifier upstage is dried and preheated making the volatile matter in the coal to evaporate into coal gas. This gas has a temperature of around 100-120 �C.
The DOWN STAGE GAS is made by a mixture of steam and air, which goes through red-hot fixed burning bed. The oxygen content in the air and steam react with the carbon in the fuel; generating the producer gas
Reaction of steam and carbon is endothermic reaction:
C + H2O= CO + H2
When oxygen and carbon react, and then heat output:
2C + O2 =2CO ; C + O2 = CO2 ; CO + H2O = CO2 + H2
In the reducing zone, quick reaction is occurred when the temperature is below 1200 Celsius degree
CO2 + C = 2CO and H2O + C=H2 + CO
When the coal gas goes through the reducing zone, flammable gas content raises rapidly, carbon dioxide and steam content decrease. Across the reducing zone, this part of coal gas is withdrawn through a series of vent in the gasifier walls and taken out through its outlet. Its temperature is around 300-400 Celsius degree and container dust and ash particles.
COOLING AND CLEANING
Step 1: The upstage gas is passed into electric detarrer which is a specially designed ESP (Electro Static Precipitator) to remove tar. Tar come from the bottom of electric detarrer is sent to the tar tank.
Step 2: The down stage coal gas is passed by cyclone separator to remove dust particles that it may contain.
Step 3: Then down stage coal gas is cooled indirectly in a heat exchanger with water to cool it by 100-120 �C.
Step 4: Then down stage coal gas is passed through a indirect air cooler to cool it by 100-150 �C.
Step 5: The Upstage and downstage coal gas are mixed in the entrance of indirect cooler, the temperature after mixing and cooling in the indirect cooler is 35-40 Celsius degree.
Step 6: Then the mixed gas goes through electric de-oilier to remove dust and light oil.
The coal gas pressure adder increases the pressure of the coal gas to the desired value and then connects to the transmitting coal gas pipelines which take the gas to the equipment.
|COAL GAS PARAMETERS
||>1400 Kcal / Nm3
||ANY PRESSURE ( 1 Kpa to 300000 Kpa )
||Ambient ~ 45 - 50 � C
||< 40 mg / Nm3
||< 40 mg / Nm3
||< 40 mg / Nm3
||NON STOP AVALIABLITY OF SYSTEM
||~ 500 �E600 days
||PIPELINE DISTANCE FROM USAGE
||Any distance ( up to 3 Km )
COAL GAS OUTPUT *1(Nm3/hr)
3500 – 4500
5000 – 6250
6000 – 7000
6750 – 7800
HEAT OUTPUT ( M cal / hr)
48 – 60
67 – 85
81 – 94
9.1 – 10.5
ENERGY OUTPUT ( Kwh )
5480 – 6970
7780 – 9870
9400 – 10900
10580 – 12250
B GRADE COAL ( > 5200 Kcal/Kg)
• Latest Technology with 6 step cleaning and cooling with no direct water contact of coal gas
• Highest gasification efficiency of > 87 %
• Lowest gas producing and running cost per Kcal of output
• High Constant GCV of coal gas > 1400 Kcal / Nm3
• Clean Gas quality with tar and dust < 80 mg / Nm3
• Zero water discharge with the use of closed cycle cooling including air cooler and indirect cooler
• 100% Phenolic water reuse
• Tar produced is low-temperature with < 3% moisture and GCV > 11000 Kcal / kg.
• Tar sale can offset up to 25 % of coal cost.
• 100% automation with PLC and SCADA systems
• Online Gas analysis
• Desulphurization for removing sulphur
1. Steel Reheating Furnaces with 100% automation
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4. Annealing furnaces
5. Ceramic tiles kilns
6. Sanitary ware Kilns
7. Bone china units
8. Refractory plants
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10. Lime kilns
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