INNOVATIVE ANIMAL MANURE TREATMENT TECHNOLOGIES FOR ENHANCED ENVIRONMENTAL QUALITY
Location: Coastal Plain Soil, Water and Plant Conservation Research
Title: Livestock waste-to-energy concepts
Submitted to: Air and Waste Management Annual Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2007
Publication Date: September 16, 2007
Citation: Cantrell, K.B., Ro, K.S., Hunt, P.G. 2007. Livestock waste-to-energy concepts. In: International Symposium on Air Quality and Waste Management for Agriculture, 16-19 September, Broomfield, Colorado. 8 p. 2007 CDROM.
Currently there is interest in energy-value-added products from thermochemical conversion processes using agriculture wastes, namely animal manures. Our objective was to review the application and integration of gasification technology for the treatment and energy conversion of animal manures. Conceptual designs that incorporate under-developed gasification technologies using dry and wet manures as feedstocks were presented. Dry wastes like poultry litter and feedlot manures can be processed directly via dry or steam gasification technology. Aqueous waste streams can undergo wet gasification processing directly to obtain a fuel gas that can be combusted or upgraded to liquid fuels and alcohols. Even still, integration of gasification is possible with current waste treatment systems utilizing solid-liquid separation processes and anaerobic digestion. The separated solids can be completely converted into a mixture of both bio-oil, methane–rich bio-gas, and synthesis gases. In addition to the energy products, wet feedstock gasification techniques provide a means to treat and clean the waste water, thus, creating a closed-loop water recycle. All of the gasification systems discussed provide an environmentally friendly method of manure disposal by eliminating pathogens and nuisance compounds and drastically reducing the land disposal requirements for manure. The major roadblocks for implementing these processes are: 1) perfecting continuous operation of modular units; 2) developing cleaning pretreatments of the manure to remove sulfur and minerals; and 3). establishing standard methods for consistently producing a uniform product.