Qualitative analysis of tar based on tar sampling conditions for empty fruit bunch gasification

The generation of tar during biomass gasification is a common phenomenon. Tar is a heavy hydrocarbon material that must be controlled; otherwise, it can damage the gasification process. Thus, the knowledge related to tar composition is crucial for the proper design of the syngas cleaning unit of a gasification process. Several studies have been conducted on tar sampling and analysis by using the cold solvent trapping (CST) method to date. However, these studies have not focused on the specific sampling parameters such as flow rate, total flow for producer gas sampling, and sampling time. Therefore, in this study, biomass gasification was conducted on a lab-scale fixed-bed gasification process using empty fruit bunch (EFB) to assess the effect of different sampling conditions on tar composition and quality. Besides, the applicability of energy conversion from EFB in form of syngas was also assessed in this study. The results showed that gasification efficiencies in this process were similar to typical gasification processes, with cold gas efficiency of about 60% and carbon conversion efficiency of about 50%. Regardless of the sampling conditions, benzene was found to be the main composition of tar generated by EFB gasification with an average concentration of 88 vol.%. Therefore, it is suggested that the syngas cleaning unit should be designed by focusing on benzene control. Moreover, it can be proposed that for reliable tar sampling results, the sampling time should be at least 20 min, the flow rate should be at least 2 L/min, and the total flow should be a minimum of 60L. However, these suggested values are not perfect and can vary depending on site conditions.