A Combined Cycle Power Generation/Alfalfa Processing System: Part 1 — Development and Testing

The Minnesota Valley Alfalfa Producers (MnVAP), a farmer owned cooperative, is developing a 75 MW combined cycle power plant integrated with alfalfa processiag facilities in southwestern Minnesota. The Minnesota Agri-Power (MAP) project is supported by the U. S. Department of Energy and a project development team that includes Stone & Webster, the University of Minnesota, United Power Association, Carbona Corporation/Kvaerner Pulping Inc. and Westinghouse. Alfalfa processing facilities separate the fibrous stem material from the protein-rich leaf fraction. The resulting alfalfa leaf meal (ALM) is further processed into a variety of valuable livestock feed products. Alfalfa stem material is gasified using air-blown fluidized bed technology to produce a hot, clean, fuel gas. The fuel gas is fired in a combustion turbine and the exhaust heat is used to produce steam to power a steam turbine. At base load, the electric power plant will consume 1000 tons per day of biomass fuel. This paper briefly describes the project development activities of the alfalfa feed trials and the combined cycle power plant. This commercial scale demonstration represents an important milestone on a continuing pathway towards environmentally and economically sustainable energy systems.