Sustainable biomass energy production and rural economic development using alfalfa as feedstock

Alfalfa is a well-known and widely-planted crop that offers environmental and soil conservation advantages when grown as a 4-year segment in a 7-year rotation with corn and soybeans. Alfalfa fixes nitrogen from the air, thereby enhancing soil nitrogen and decreasing the need for manufactured nitrogen fertilizer. With alfalfa yields of 4 dry tons per acre per year and with separate alfalfa leaves being sold as a high-value animal feed, separated alfalfa stems can be economically viable fuel feedstock for a gasifier combined cycle power plant. This paper reports on a feasibility study for an integrated biomass power system, where an energy crop (alfalfa) is coupled to a processing plant and a power plant (integrated gasification combined cycle with hot gas cleanup) in a way that benefits the joint venture of an alfalfa producers cooperative and a utility entity. The sale of a mid-level protein animal feed co-product and electricity both support the production cost of alfalfa. The co-product/fuel processing operation uses a common train of equipment, thereby requiring neither product to carry the total cost. The power plant provides an important continuous demand for the feedstock and results in continuous supply of leaf product to provide a reliable supply neededmore » for the leaf meal product.« less