Waste gasification process producing quench-granulated, anti-leaching slag

摘要

The new method puts residual waste materials (1) to environmentally-friendly use. Bio-mechanical treatment precedes gasification to a product rich in hydrogen and carbon dioxide. In the new process, waste is comminuted (2) and freed (3) of metals (4) and tramp waste (5), for composting (7). The volume-reduced and water reduced output is screened. Fines (11) are briquetted (12). Briquettes (13) and oversize (14) are fed down through pyrolysis (16), the char migrating downwards, conditions changing smoothly from pyrolysis to gasification (17), the solids flowing in countercurrent to an oxidant gas (18). Gaseous product is partly withdrawn, to form a source of energy or material, for further application. The remainder is recycled for heating and pyrolysis in countercurrent to the solids, picking up volatiles before withdrawal. This gas is burned in oxygen and/or air in a reaction chamber below the trickling bed. The gas, thus heated, is supplied as the gasification medium, oxygen rich, to the gasification stage, from below. The temperature and composition of the reaction gas may be varied as a function of the oxidant proportion and/or by changing the oxygen content of the oxidant.