Liquefied wood was tested in an experimental turbine engine with different primary air temperatures. Variation of primary air temperature was used to emulate two types of micro gas turbine generators – fully recuperated and simple cycle setups resulting in different temperatures of combustion chamber intake air. Results indicate that different temperatures, velocities, and flow conditions in primary zone of combustion chamber strongly influence droplet penetration depth and rate of mixture formation as well as emissions formation. Emission trends of CO and THC were significantly higher in simple cycle mode, generally indicating insufficiently stable combustion process, whereas in case of high primary air temperatures only NOx emissions of liquefied wood were slightly elevated and CO and THC emissions significantly reduced, indicating good combustion efficiency. With low primary air temperatures, also notable amount of charred deposits were found on injection nozzle and combustion chamber walls.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 13881883Presented study deals with combustion analysis of two different fuels – liquefied wood and tire pyrolysis oil in a experimental gas turbine. Combustion properties are compared to those of diesel fuel and mixture of glycerol and diethylene glycol which serves as a basis for liquefaction of wood. The original contribution of this analysis is the in-depth comparison of the combustion and emission phenomena of both investigated fuels under different operating conditions. The results indicate significantly higher CO (carbon monoxide) and THC (total hydrocarbons) emissions for liquefied wood Emissions of tire pyrolysis oil closely resemble diesel fuel with the main difference being NOx emissions due to high share of fuel bound nitrogen. The opacity measurements are very high for liquefied wood due to its oxygen content , while tire pyrolysis oil contains high share of soot precursors and has thus high smoke number (low opacity). These results indicate that tire pyrolysis oil can be exploited directly in gas turbines, whereas liquefied wood requires adaptations in the fuel supply system and a narrower range of operating conditions.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 13882139The goal of the study was to estimate the feasibility of a microturbine engine (MGT) to be operated with innovative energy carriers with specific focus on liquefied lignocellulosic biomass. The data is first used to obtain a reference for operating conditions on an experimental microturbine engine stationed in University of Ljubljana. Secondly, the possibility to perform further experiments with liquefied wood on a MGT, stationed in VUB is evaluated and discussed based on construction, control system design and key operating parameters of MGT. The results suggest that fuel system in University of Ljubljana has sufficient capacity and operational stability to feed the T100 turbine. Required adaptations are linked first to adaptation of T100 on liquid fuels, with specific solutions required for high carbon residue in high viscosity fuels. The preliminary solution is suggested with incorporation of new combustion chamber, developed at University of Ljubljana. The control system of T100 will most likely require pilot flame, lit by natural gas to keep the closed-loop fuel flow control functional. In terms of energy share, the pilot fuel would account up to 10% of total energy delivery.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice
COBISS.SI-ID: 14558235