The raw hot gas from producer can be delivered through insulated mains as such to the furnaces and plants nearby. So that both potential energy of gas (CV) and sensible heat can be utilized. A more prevalent practisc is to cool the gas and purify it to remove deleterious constituents, for example H2S and then distribute to plants.
Normally following efficiency values are reported in the literature:
Cold gas efficiency ≈ 60-80%
Hot gas efficiency ≈ 90%
Losses ≈ 9%
Illustration
Determine Material and heat balance of a gasifier and calculate efficiencies. The analysis of various inputs and outputs are given. Temperatures of input and outputs are also given.
Figure 37.2: |
Material balance diagram |
Basis 1 Kg coal.
Volume of producer gas(fuel gas)
Let Y Kg mole producer gas
C in coal = C in producer gas + C in ashes
0.791/12 = (0.07 + 0.21 + 0.025) Y + (0.09 – 0.061)
Y = 0.208 Kg mole or = 4.66 m3/Kg coal (1 atm, 273K)
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