Utilizing Animal Tissue Biomass in Coal-Fired Boilers: A Step Closer Towards Implementation?

摘要

Livestock deaths pose daunting carcass-disposal challenges regardless of the cause -accidental disease entry, typical animal-production mortality, natural disaster, or an act of terrorism. Effective means of carcass disposal are essential regardless of the cause of mortality but are perhaps most crucial for disease eradication efforts. In addition, with the identification of the first case of bovine spongiform encephalopathy (BSE) in the United States in December 2003 regulatory changes are being promulgated to ensure confidence in the safety of the food supply. These regulations may require the removal of cattle mortalities and specified risk materials (SRM) from being utilized in the production of rendered animal feed, thereby increasing the quantity of material that must be disposed. There are several disposal technologies being considered by industry and regulatory agencies including burial, incineration, composting, rendering, lactic acid fermentation, alkaline hydrolysis, anaerobic digestions, and novel technologies. Taylor Packing Company-Cargill Meats Solutions (Taylor-Cargill), with the assistance from Penn State, has been exploring the possibility of cofiring animal-tissue biomass (ATB) in coal-fired boilers as an additional disposal option. In July 2004, Penn State, Taylor-Cargill, and McDonalds Corporation hosted a workshop at Penn State to discuss and develop strategies to utilize ATB as a fuel in industrial and utility boilers, brainstorm on the development of a national infrastructure that could utilize ATB as a fuel on both a routine and large-scale emergency basis, and stimulate public-private collaboration. Representatives from federal and state government, meatpacking and rendering industries, food industry and service, banking, equipment supply, cogeneration companies, fluidized-bed boiler manufacturing, and academia attended the workshop. The workshop consisted of presentations that outlined the issues of carcass and tissue disposal and provided overviews of the technology of energy generation from fluidized-bed boilers, followed by breakout sessions that addressed the issues of concept-to-commercialization, logistics, and economics and incentives. This paper summarizes the findings from the workshop, which were also submitted to the Food and Drug Administration (FDA) in response to an advanced notice of public rulemaking for comments on economic and environmental issues associated with the disposal of animal tissues. The feasibility of the technology is discussed as well as pilot-scale tests that are underway to demonstrate the handling, combustion performance, and emissions when cofiring ATB and coal in a fluidized-bed combustion system. Penn State's Energy Institute is performing the testing with technical assistance from fluidized-bed boiler vendors such as The Babcock & Wilcox Company and Foster Wheeler North America Corporation. The National Cattlemen's Beef Association (NCBA) is providing the funding for the testing with Taylor-Cargill also providing financial support and the ATB.