Fixed bed gasification process

摘要

Gasification is performed under pressures in the range from 5 bars to 150 bars with oxygen, steam and/or carbon dioxide as gasifying agents. Pellets are fed to the top of a fixed bed in the gasification reactor. The gasifying agents are introduced into the fixed bed from below. Mineral constituents are withdrawn as solid ash or liquid slag from the lower end of the fixed bed. The pellets are made from fine-grained hard coal which has a particle size below 1 mm and contains 3 to 10 wt. % of fines having particle sizes not in excess of 2 micrometers and 70 to 80 wt. % of particles not in excess of a fraction not in excess of 63 micrometers. The fine-grained hard coal is mixed with bentonite to obtain a mixture which contains 1 to 8 wt. % bentonite. With an addition of water, the mixture is shaped to form pellets which contain 15 to 25 wt. % water. The pellets are fed in an undried, moist, plastically deformable state to the top of the fixed bed.