Liquid Bio Fuels for Gas Turbines

Abstract: In this study the different liquid biofuels that could be used as alternative fuels in gas turbines are reviewed. The pre-conditions are biofuel in liquid state, suited for seven specific gas turbines at E.ON Värmekraft that are a part of the disturbance reserve of Svenska Kraftnät. The alternative fuels need to comply with the agreement with Svenska Kraftnät. The most probable candidates are biooil, dimethyl ether, bio-ethanol, Fischer-Tropsch synthesized fuels, straight vegetable oils, fatty acid (m) ethyl esters (FAME, RME, bio-diesel) and hydro-treated (or -genated) vegetable oils (HVO). These fuels are studied and their different properties are listed. Earlier works where these fuels have been used in gas turbines are studied and conclusions are drawn from this. Several issues concerning combustion and emissions with respect to gas turbines are reviewed. The gas turbine fuel consumption regarding alternative fuels is presented and a market research of prices of the alternative fuels is performed. The specific sustainability demands of both the Swedish Energy Agency and E.ON are discussed. An analysis is performed of the alternative fuels, of the earlier work and how this will affect the issues with combustion and emissions. Some specifics concerning the use and storage of these alternative fuels are also analyzed. An economic analysis is performed calculating the total cost from using these alternative fuels, including cost for fuel and investments and possible subsidies. The conclusion is that it is both technically feasible to use liquid biofuels in gas turbines, and with some requirements, there can be an economical gain in it. Though this requires large investments. Biooil or Pyrolysis oil could, during an estimated time period of 15 years, with subsidies, cover the material investments needed for the conversion. Disregarding economy, there is a relatively new alternative fuel on the market, HVO, that seems very good and it is in some aspects better than the current fuel. The price on this fuel is on the other hand very high due to the fact that it can substitute diesel fuel for vehicles.