The Flash Pyrolysis of Solid Wastes

During the last three years the Garrett Research and Development Company has developed an integrated resource recovery system for the recycling of municipal solid waste. Magnetic metals and a very high purity glass are recovered, and the organic components are converted to good quality fluid fuels. The heart of the process is a proprietary flash pyrolysis technique which enables more than one barrel of low-sulfur oil to be obtained from each ton of raw, wet municipal refuse. The reactor operates at modest temperatures and pressures only a few pounds above atmospheric, and requires no costly supplies of catalyst or hydrogen. The process is highly versatile. Such diverse feedstocks as coal, packer truck waste, tree bark, rice hulls, sewage sludge, cattle feedlot waste, and used rubber tires have all been converted to gas or oil in a laboratory reactor or at a 4-ton/day pilot plant. Combustion tests on the oil produced from municipal waste have shown it to be a perfectly acceptable substitute for the No. 6 oil burned by electric utilities. Activation of the chars from municipal and agricultural wastes is being pursued. If successful, a cheap, throwaway form of powdered activated carbon would be available for the treatment of secondary effluent at sewage plants. The pyrolytic char from used tires shows good potential as a replacement for general furnace black. The economics projected for a plant capable of recycling 2000 ton/ day of municipal refuse shows that, under municipal ownership, revenues from the sale of oil, glass, and magnetic metals would slightly exceed operating costs.