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Show 1. INTRODUCTION Livestock and poultry confined feeding operations produce 52 million dry tons of economically recoverable manure each year (Van Dyne, et al., 1978). These animal wastes must be properly managed to prevent water and air pollution problems (Fu, et al., 1974). Most of the manure is utilized on agricultural lands as fertilizer. Other uses of manure include feedstuffs and feedstock for both biological and thermochemical processes. Manure solids can be pyrolyzed and gaseous and liquid products may be used as an energy source. The pyrolyzed manure sol id can be used as a carbon black substitute and as a filler material (Dunn, et al.). An efficient way is to combust manure directly and extract the energy near the feedlots. The annual fuel cost for Texas cattle feedlots is about $6 to 8 per head of cattle on feed. Most of this fuel is consumed to process the feedstuffs at the feedlots (Sweeten, et al., 1980). Direct combustion of all manure collected at cattle feedlots in Texas could produce six times more energy in the form of steam and electricity than is required for feed processing, thus the excess energy can be fed into the general electrical network. Feedlot manure is a low grade fuel due to the high moisture and ash content (Sweeten, et al., 1980). Also, emissions of sulphur, nitrogen oxides, and particulates may exceed air quality standards set up by the U.S. Environmental Protection Agency. Most of the previous research has dealt with pyrolysis and gasification or partial oxidation (Walawander, et al., 1973; Huffman, et al., 1978; Kreis, et al., 1979; Raman, et al., 1982). Walawander 2.4.2 |