Tar removal with anaerobic fermantation

Tar is one of the major problems of the thermochemical conversion systems such as gasification and pyrolysis. It is composed of aromatic hydrocarbons which cause severe damage in the system. These damages include heat loss, corrosion, soot, deactivation of catalysis and fouling in the pipes and lines. In this study, current literature is searched for present tar removal technics and a new system is designed as a hybrid of biological and thermochemical systems. The experiments are completed in three steps. Firstly, suitable material for the pyrolysis is determined as wood chips among the samples of cow manure, chicken manure, eucalyptus and wood chips pyrolysed at 500-600˚C. Secondly, gravimetric analysis of pyrolysis gas is occured by washing with chemical solvents, aceton and isopropil alcohol (this process also known as Cold-Trapping Method). This method is applied after pyrolysis. Gravimetric analysis results are found as 0.158, 0.194, 0.165 g/l, respectively. According to the results of three experiments, aceton is determined as the ideal solvent. Wave length analysis is carried out at 285 nm. Absorbance values are established as 0.3514, 0.1545, 0.1195, 0.0976 and 0.025 from the 1st bottle to the 5th respectively, with regard to Lambert-beer law. On the 3rd step, fertilizer waste is obtained from Torbalı plant with the capacity of 25 m 3 is added to the system after the pyrolysis reactor. 10, 20 and 30 L syngas is passed through the fertilizer waste and gravimetric tar amounts are observed as 0.159, 0.089 and 0.075 g/L, respectively. According to these results, tar removal yield is calculated 56.09%. Absorbance values are established as 0.3068, 0.2741, 0.2449, 0.1701 and 0.1249 from the 1st bottle to the 5th, respectively. Finally, fertilizer waste which treated by syngas is incubated at 35 ˚C for 12 days. There isn't any gas generation observed. Alkalinity and Ph analysis are applied to fertilizer waste and results are evaluated. Key word: pyrolysis, fertilizer waste, tar, syngas, hybrid system