The work presented here characterises the influences of different waste-derived fuels on the combustion process in a microturbine. The two most common types of solid waste are converted into liquids by liquefaction in polyhydric alcohols and by pyrolysis to produce the novel fuels LW (liquefied wood) and TPO (tire pyrolysis oil). Baseline results were obtained with diesel fuel and with raw polyhydric alcohols otherwise used in wood liquefaction process. The original contribution of this analysis is the in-depth comparison of the combustion and emission phenomena of LW and TPO under different operating conditions. The results revealed significantly higher CO (carbon monoxide) and THC (total hydrocarbons) emissions for LW due to its reduced atomisation ability and increased spray penetration in line with the physical and chemical properties of the fuel. The combustion properties of TPO resembled those of diesel fuel in terms of CO and THC. NOx (nitrous oxides) emissions reflected the elemental composition of the fuels. In addition, pronounced soot formation is observed when utilizing TPO, whereas for LW, the opacity measurements are surprisingly low. These results indicate that TPO can be exploited directly in gas turbines, whereas LW requires adaptations in the fuel supply system and a narrower range of operating conditions.
COBISS.SI-ID: 13791003
Presented study investigates the influence of primary air temperature on combustion of innovative lignocellulosic biofuel, obtained through solvolysis of spruce wood in multifunctional alcohols. The combustion conditions are imitating those in typcial microturbine setups, with variation of primary air temperature allowing to emulate two types of micro gas turbine generators i. e. fully recuperated and simple Joule 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 emission formation. For the innovative lignocellulosic biofuel emission trends of CO and THC were found to be significantly higher in simple cycle mode, whereas no influence of operation mode was observed for baseline diesel fuel. NOx emissions of innovative biofuel generally increased in regenerative cycle mode and also became sensitive on turbine inlet temperature, with similar trends being observed with diesel fuel. In the case of innovative fuel, deposits of char and polymerized fuel were observed on the combustor walls after operation in simple cycle mode, whereas in regenerative cycle mode, only small amounts of ash deposits were found on hot path surfaces, indicating beneficial influence of high primary air temperatures on combustion efficiency of innovative fuel.
COBISS.SI-ID: 13804059
Presented study focuses on emission evaluation of different types of liqueified wood during combustion in a laboratory scale gas turbine. Tested fuel types were: basic formulation (pH 2,5 and 25% biomass content), formulation with increased wood content (pH 2,5 and 33% biomass content) and partially neutralized formulation (pH 5,5 and 25% biomass content). The formulations therefore represent a step towards fuels with increased techno-ecnomic value. The results suggest that strong biomass content on CO and THC emissions is present, with higher biomass content leading to higher CO and THC emissions. The reason for this lies in specific molecular composition and higher molecular mass of formulation with 33% biomass content which increases the viscosity of the product and influences the spray formation phenomena. This in turn leads to higher CO and THC emissions. On the other hand, partially neutralized formulation exhibits same values of CO and THC as basic formulation with 25% biomass content. The influence of partial neutralization is visible only through increased NOx emissions, which are roughly 30 ppm higher over entire operating range. The reason for this lies in 0,71% addition of ammonium hydroxide with which additional 0,1 mol/L of nitrogen is added to liquefied wood. The elevation of NOx emissions can therefore be attributed to increased share of FBN in the fuel. Contrary, emissions of NOx with fuel with 33% of biomass content are slightly lower, which can be attributed to slightly lower primary zone temperature.
COBISS.SI-ID: 13392411