Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2008
Publication Date: 4/28/2008
Citation: Cantrell, K.B., Ducey, T.F., Ro, K.S., Hunt, P.G. 2008. Livestock waste-to-bioenergy generation opportunities. Bioresource Technology. 99:7941-7953.
Interpretive Summary: Animal waste can be converted into alternative energy products such as gases and liquid fuels. We reviewed the technologies that can process animal waste biologically or with high temperatures and turn the waste into gas or liquid fuels to be used for heat and power generation or transportation fuels. From this review, we present a conceptual design of a combined system that uses algae to capture the carbon dioxide from these systems and generate algal biomass. The algal biomass can be converted in alternative energy products using the same systems reviewed. The combined system allows for future farming sustainable and have little environmental impact.
Technical Abstract: The use of biological and thermochemical conversion (TCC) technologies in livestock waste-to-bioenergy treatments can provide livestock operators with multiple value-added, renewable energy products. These products can meet heating and power needs or serve as transportation fuels. The primary objective of this work is to present established and emerging energy conversion opportunities that can transform a livestock waste treatment from a liability to a profit center. While biological production of methanol and hydrogen are in early research stages, anaerobic digestion is an established method of generating between 0.1 to 1.3 cubic meter per treatment volume per day of methane-rich biogas. The TCC processes of pyrolysis, direct liquefaction, and gasification can convert waste into gaseous fuels, combustible oils, and charcoal. Integration of biological and thermal-based conversion technologies in a farm-scale hybrid design by combining an algal CO2-fixation treatment requiring less than 270 square meter of treatment area with the energy recovery component of wet gasification can drastically reduce CO2 emissions and efficiently recycle nutrients to make future farming sustainable and environmentally benign.