The Pyrolysis of Refuse Components

During the heating of organic refuse out of contact with air, water, gases and liquids are evolved, leaving a char residue. Ten refuse components from domestic waste were distilled on a laboratory scale, the gaseous products were analyzed and the yields determined. The gases included mainly CO2, CO, H2, CH4, with mixture calorific values of 300 400 Btu per standard cu ft. The yield weights were roughly equally divided among water, gas, organic liquids and char. The rate of heating affected the yields. In­ creased heating rates decreased the char, water and carbon dioxide, and increased carbon monoxide. The highest gas yields may be expected from flash heating. The economical disposal of municipal and industrial refuse is a challenge of growing proportions. The quantity of waste paper, wood, textiles, garbage, metal and glass is over 150 million tons a year in the United States alone, and is increasing faster than the population. The common open dump is being outlawed. Sanitary landfilling requires acreages that are usually not available near large urban centers. Compbsting reduces the organic matter only partially and is otherwise seldom economical. Incineration is a grow­ ing method of disposal, but is an expense. The conversion of refuse to useful products with economic value is attractive because, 1) the raw material is available at negative cost, 2) it is available in large quantities at urban centers where markets for products and energy also exist, 3) the organic matter can readily be converted by heat to gas, liquids, char, ceramic aggregates and metal. The yields of gas, liquid and char could be varied over a range depending on the method and rate of heating. This paper reports on exploratory laboratory tests of destructive distillation of organic wastes, and the prospects for complete gasification of the orga,nic matter. The objective is to determine the quantity and quality of the product gas that might be produced for use as a hot, raw boiler fuel, and possibly for chemical manufacture. COMPOSITION AND ANALYSIS OF REFUSE The major class of refuse is that from house­ holds, and is about 3 lb. per capita day. It consists primarily of paper products, with less than 10 per­ cent each of glass, metal and garbage, and less than 5 percent each of textiles, wood, plastics and dirt. A fairly typical chemical analysis of mixed refuse: Presented at the 60th Annual Meeting of the American Institute of Chemical Engineers, November 26-30,1967.