TARs are a mixture of heavy and light hydrocarbons produced from pyrolysis and gasification of biomass and waste, as condensable volatiles in the syngas. Given their relatively low dew point, they are usually removed from syngas to avoid condensation and fouling of engines and equipment. Vegetable oil scrubbing compared to water scrubbing yields oil tar mixtures which is a renewable fuel and may be useful successfully to power a gas turbine. The feasibility of burning TAR, blended vegetable oil, in a combustor of a turbine is investigated. Computational simulations with a CFD software were performed to analyze evaporation and combustion processes of vegetable oil-tars mixture compared with pure vegetable oil and diesel, in terms of residence time, temperature distributions, inlet turbine conditions.
The results show difficulties in evaporation of both vegetable oil and vegetable oil-tar mixture compared to diesel, with consequences in the combustion in terms of temperature distributions and higher NOx emissions. Preheating of vegetable oil and vegetable oil-tar mixture improves their evaporation approaching the results to those of the diesel case.