Hydrothermal Extraction and Gasification Process for Low Rank Coal Conversion

The present study primarily focuses on hydrothermal Extraction and Gasification of Low-Rank Coal with Catalyst Al2O3 and Pd/Al2O3. Increasing the efficiency of the conversion of the coal gasification process can be done by adding a catalyst. Potassium carbonate (K2CO3) is a catalyst capable of increasing the rate of reaction in the coal gasification process. This research attempts to increase the quality of low-rank coal using a hydrothermal process with hot compressed water (HCW) at 200ºC and 3 MPa. The products from this process were solid residue and liquid filtrate with organic components. Synthetic gas was the byproduct of the filtrate's gasification. The outcome shows that a higher water flow rate may cause the filtrate's organic component to increase. Using a catalyst sped up the extraction process and increased the amount of organic matter in the filtrate while decreasing its content in the residue. FTIR (Fourier transform infrared spectroscopy) research showed that Pd/Al2O3 catalyst enhanced the efficacy of HCW coal extraction. Increasing the process temperature will increase the amounts of CO and H2 gas. In this research, the highest net heating value at 800oC using K2CO3 solution and Pd/Al2O3 catalyst was 17,774.36 kJ/kg. The highest cold gas efficiency was 91.29% and the best carbon conversion was 34.78%. The addition of the catalyst can increase the rate of the degradation processes of the organic compounds. Hydroxyl groups of the solid product were found to be reduced based on the FTIR results, with absorbance unit decrease from 45% to 25%.