Characteristic of tar content and syngas composition during beech updraft gasification

This work aims at study the effect of the operating conditions like equivalence ration and temperature on the updraft gasification of beech wood. The main aspects was to analyze the influence of temperature distribution in the reactor and equivalence ratio on the fuel consumption, syngas composition as well as tar formation characteristics during the gasification process. The light tar content and composition were analysed using gas chromatography coupled with mass spectrometry (GC-MS). Experimental results have shown that the amount of air supplied does not affect the parameters of the gasification process linearly. For lower ER value there was high fuel consumption and high bed temperature in the gasifier, which results in high caloric value of syngas. The results showed that tar yield during updraft gasification depends on the temperature and equivalence ratio. With the increase value of ER and the decrease of temperature on the surface of the bed, the total amount of tar yield increased. The highest temperature on the surface of the bed leads to the smallest tar yield, which can be associated with thermal cracking. The results indicate that both light and heavy tar are changing nonlinearly with different operating conditions. In addition, with decreasing temperature and increasing ER values, the amount of phenol and oxidized aliphatic compounds in the tar samples increased while the BTEX amount decreased. The amount of PAHs, in relation to the temperature and ER, was kept low in all cases.