CO-FIRING STEAM GENERATORS: MODIFYING EQUIPMENT AND OPTIMIZING OPERATIONS

Abstract

According to the US Energy Information Administration, steam turbines generated 70.5% of the U.S. net generation of electricity for all sectors in 2012, but only 2.02% of the electricity generated from steam turbines is attributed to wood or waste as the fuel. The opportunity to integrate biomass at existing coal power plants potentially reduces costs and emissions from coal-fired generation operations while increasing revenues through renewable energy credits (RECs) generation. By examining hourly data from a plant experimenting with different fuel mixes of wood and wood waste biomass, tire-derived fuels, coal and petroleum coke, this study aims to identify profitable opportunities to modify existing coal power plants to co-fire their facility with REC eligible fuels. Do the cost-savings and revenues offset the capital expenses of modifying equipment? Is this a long-term solution to improve emissions and meet regulations? This masters project aims to improve the public’s understanding of the upfront investment and the ongoing operational adjustments required to co-fire biomass at existing coal-fired power plants. As a method to acquire renewable energy credits (RECs) in states and districts with renewable portfolio standards (RPS), plant management may leverage co-firing as a way to meet emission standards without installing expensive control systems. Efficient public policies and regulations should account for the entire costs and benefits of biomass co-firing initiatives, and this report aims to present the complexities of the variables involved in an accessible format. Existing research focuses on the chemistry involved in co-firing, the costs of installments, the efficiencies of boilers and the impacts on emissions independently. This text brings together these related topics in a cohesive manner. By evaluating the operations of a plant testing fuel mix ratios, this report makes recommendations about conditions that create high value outcomes. By applying those findings to a coal-fired power plant in Colorado with similar characteristics, the report recommends that the plant should integrate biomass co-firing to resolve current challenges.