SPRAY COMBUSTION AND EMISSIONS OF A HYDROTHERMAL LIQUEFACTION BIOFUEL FOR GAS TURBINE APPLICATIONS

Biomass liquefaction oil (BLO), obtained from biomass resources through thermochemical processes like fast pyrolysis (FP) or hydrothermal liquefaction (HTL), is widely regarded as one of the most economically feasible energy solutions in our future sustainable energy mix. However, the utilization of BLO as a drop-in fuel in the current in-line gas turbines has encountered several challenges due mainly to the difficulties in atomization and ignition, originating from the fuel's chemical composition and physicochemical properties. The present study compares the combustion performance and gas- and solid-phase emissions of a HTL oil (also called biocrude), as well as its diesel blends, with those of a conventional FP oil (also called bio-oil). Considering diesel as a baseline fuel, the properties and combustion performance of the HTL oil compare favorably with those of the FP oil. An anchored spray flame using the 100% HTL oil is achieved in the experiments with much smaller degrees of fuel coking and nozzle clogging problems and a lower amount of particulate matter (PM) emissions. However, its CO and NO emissions are measured higher by more than two times. The insights drawn from the present study indicates the potentials of high quality HTL oils as sustainable fuels to replace fossil fuels in gas turbines and other energy conversion systems.