MODIFYING ZEOLITE INTO CATALYST FOR TAR CRACKING PROCESS

• Main Author: (NIM: 23015015), ASLAMIAH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25860
• Institution: Institut Teknologi Bandung

<p align="justify">Producer gas from gasification process still has many impurities and among these impurities, tar has been identified as a major problem in the gasification process. Tar buildup can cause tool blockage, corrosion, catalyst deactivation and its carcinogenic properties. This can result in serious operational and maintenance problems. Catalytic tar cracking can be done using natural zeolite catalysts. The availability of natural zeolites in Indonesia is very abundant and low in price. Zeolites have much better stability and selectivity than other catalysts. However, natural zeolites still contain many impurities (Na+, K+, Fe3+, Mg2+, Ca2+) and has poor crystallinity. This deficiency makes natural zeolites need to be modified first to remove impurities and increase their crystallinity so that their activity increases. <br /> <br /> <br /> This research is aimed at studying the modification of natural zeolite into catalysts and their characterization, studying the activity of catalysts and tar conversion by using tar model compounds, toluene, and studying the effect of catalyst modification treatment. Modification of natural zeolite from Sukabumi was carried out through calcination process at 550oC for 12 hours, ion-exchanged with 2M NH4NO3 solution for 2 hours and acid leaching with 6M HNO3 solution for 3 and 6 hours at 90oC respectively, with a ratio of 1 g zeolite and 20 mL of solution. In addition, this study also investigated the process variables namely catalyst modification treatment. Modified catalysts were then characterized to determine the catalyst crystallinity using XRD, zeolite composition (Si/Al ratio) using XRF, and pore surface area using the BET method. Modified zeolite is used for cracking process with toluene as tar model and steam using a fixed bed reactor with S/T ratio 10 and GHSV 5100/h for 8 hours. Operating conditions are carried out at a temperature of 750oC and atmospheric pressure. The parameter that is used as a benchmark for the success of tar cracking is the conversion of the decrease in toluene produced which is analyzed by Gas Chromatography (GC). <br /> <br /> <br /> Sukabumi zeolite has 63.3% crystal structure which is dominated by the mordenite phase and the rest is amorphous. The use of NH4NO3 as an ion-exchange agent works quite well, although the ion that can be taken is still limited. The use of HNO3 in addition to stirring time also did not have a significant effect on toluene cracking. The Si/Al ratio obtained did not experience significant changes. Pore surface area increased along with catalyst modification treatment with the highest gain achieved by catalyst KS.GN.63 which was 208.4 m2/g. However, the catalyst KS.GN.66 has decreased which is 5.5 m2/g. This is because the acid concentration is too high due to the long stirring time which causes the mesopores in the catalyst to collapse and form new micropores. The highest toluene conversion was obtained in the KS.GN catalyst which was 90.29% with a pore surface area of 20.8 m2/g. <br /> <p align="justify">