Coke Oven Gas generation and usage Apr10

Coke Oven Gas generation and usage...

Coke Oven Gas generation and usage During the carbonization of coking coal in a coke oven battery for the production of coke, around 25-30% of the coal charged is driven off as effluent gases rich in volatile matter and moisture. This gas is known as coke oven gas (CO gas). In the non recovery or heat recovery coke ovens this gas is burnt in the oven itself and provides the required heat for the carbonization of coal. In case of by product battery, the evolved gas is removed as raw gas and is treated in a byproduct plant to give a clean fuel gas. In the byproduct plant, condensable, corrosive and economically valuable components are removed. During the cycle of coking, the gas is produced during majority of the coking period. The composition and rate of evolution of the CO gas changes during the period and the evolution of CO gas is normally complete by the time the coal charge in the battery reaches 700 deg C. The final yield of clean coke oven gas after treatment in the byproduct plant is around 300 N Cum per ton of dry coal. The yield of gas is dependent upon i) volatile matter in the charge coal and ii) carbonization condition. The density of CO gas at standard temperature and pressure is 0.545 Kg/Cum. The raw CO gas may contain hydrogen and methane, ammonia, carbon monoxide, carbon dioxide, ethane, ethylene, benzene, oxygen and nitrogen, hydrogen sulfide, water vapor, cyclopentadiene, toluene, naphthalene, hydrogen cyanide, cyanogen, and nitric oxide. The typical composition of the main components in the raw coke oven gas is in Tab Tab 1  Typical analysis of Raw coke oven  gas Component Unit Dry basis Actual composition Water saturated at   80 deg. C Water...