Liquid biofuels utilization for gas turbines: A review

The global demand for utilization of renewable fuels in gas turbines has been on the increase to secure a sustainable, and pollution free environment. In this paper, the reviewed studies were on different liquid biofuels production methods such as the catalytic conversion of biomass, gasification, pyrolysis and transesterification. The review also included different studies on directly fired gas turbine (DFGT) and externally fired gas turbine (EFGT) utilizing biomass and liquid biofuels. Furthermore, this study elucidated the use of biofuels in clean combustion methods scalable to gas turbines such as colourless distributed combustion (CDC), high temperature air combustion (HiTAC), moderate or intensive low oxygen dilution (MILD) combustion and catalytic combustion. The discussion included the effect of different input parameters associated with the clean combustion systems that have influence on the attainment of ultra-low emissions of NOx and CO under premixed and non-premixed modes. As for the fuel types, biodiesel is one of the most studied biofuel in gas turbine especially in small-scale micro gas turbine (MGT) engines. The materials for the path of hot gas, types of fuels, heat recovery and cogeneration techniques are the variables, found to be affecting the performance of the DFGT. As for the EFGT, the high temperature heat exchanger with its lower turbine inlet temperature of 700-900 °C is generally the main limiting factor for this technology. The paper concluded by highlighting relevant and recent findings, thereby proposes a further research to improve the versatility in the utilization of liquid biofuels in gas turbines.