Fluid-bed pyrolysis of solid-waste materials

Pyrolysis is the thermal decomposition of carbonaceous materials in the absence of oxygen. The yields of gases, liquids, and solids are based on the chemical structure, size, and shape of the material to be pyrolyzed, the temperature for decomposition, and the heating rate. The pyrolysis products can be burned in the presence of oxygen, to form carbon dioxide, water, and heat. Kaiser et al., used simple retont apparatus to pyrolyze the individual components found in municipal refuse at atmospheric pressure and 1500 deg F. Typical waste analysis included paper, plastic, leather, rubber, food wastes, grass, tree leaves, wood, textiles, glass, ceramics, stones, and metals. Municipal solid waste was found to have a high H/C ratio and is potentially attractive for the production of fuel gas. High conversions of wastes to low molecular weight gases could be achieved in a fluidized bed. Municipal solid wastes do not need pretreatment. (MCW)