Optical measurement of tars in a fluidized bed gasifier: influence of fuel type and gasification parameters on their formation

Gasification is considered to be one of the most promising ways to use biomass for producing liquid fuels, chemicals, synthetic natural gas, or hydrogen. One of the most important problems during the gasification process is the amount of condensable hydrocarbons (tars) which are produced within the process and create problems in the downstream use of the producer gas for energy and liquid fuel/chemical production. Except for the conventional measurement techniques for the determination of the tar content in the producer gas, innovative optical techniques can also be successfully used. In an effort to improve the already existing tar measurement methods, this scientific work deals with an online and nonintrusive quantitative and qualitative measurement technique for the analysis of tar compounds, which allows the investigation of the influence of different operating conditions on the tar content in the producer gas from a fluidized bed gasifier. The impact of the operating conditions (temperature, pressure, steam-to-biomass ratio) of the gasification reactor as well as of the type of biomass feedstock used on the quality of the producer gas and especially on the tar content is examined and analyzed.