THERMOCHEMICAL CONVERSION: A PROSPECTIVE SWINE MANURE SOLUTION FOR NORTH CAROLINA

The growth of North Carolina's swine industry in recent decades has led to a subsequent increase in the production of swine manure. This manure represents a potential threat to environmental and human health, as well as an opportunity to add value to pork production. Technologies for treating swine manure safely while generating products to offset costs are part of an expanding field of research centered on sustainable food production for our growing population. Thermochemical conversion processes use heat to degrade organic feedstocks and drive chemical reactions, which generate valuable products. The high moisture content of swine manure is prohibitive for most thermochemical processes, but gasification and hydrothermal carbonization may be more accommodating. Gasification, a time-tested thermochemical conversion process, yields a combustible gas through a series of endothermic reactions, and hydrothermal carbonization yields a solid, coal-like char that can be used as a fuel or chemical precursor. Advances in thermochemical conversion processes have indicated the potential for yielding valuable products from swine manure, but viable scalable processes are still under development, requiring further research to apply these processes to swine manure management and evaluate the usefulness of their products. This review (1) describes, generally, thermochemical conversion via both hydrothermal gasification (HTG) and hydrothermal carbonization (HTC), (2) shows the usefulness of each conversion process for biomass, and (3) discusses the potential of HTG and HTC of swine manure to enhance the value of pork production.