THE CATALYST ACIDITY EFFECT TOWARD ACTIVITY AND SELECTIVITY OF Co/γ-Al2O3 BASED FISCHER-TROPSCH CATALYST: POTASSIUM AND MANGANESE LOADING

• Main Author: HAFIZAN RESHA - NIM: 23015035 , AHLUL
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25153
• Institution: Institut Teknologi Bandung

<p align="justify">Indonesian fuel consumption has increased 4% while production has fallen down 2.7% which forced Indonesia to import 33,565.89 tons of oil equivalent (toe) of petroleum every year. On the other hand, Indonesia’s annual production excesses relative to consumption of natural gas and coal, 31,779.38 toe and 160,734.12 toe respectively. Therefore, a technology should be performed to convert excessed natural gas and coal into fuel, namely Fischer-Tropsch synthesis (FTS). <br /> <br /> Fischer-Tropsch synthesis converts syngas (H2 and CO), which can be generated from natural gas and coal, into hydrocarbons through catalytic process. An invented catalyst for FTS is Co/&#947;-Al2O3, but it has to be enhanced to get higher conversion and selectivity. The addition of electronic promoters, such as manganese (Mn) and potassium (K), enhances the performance of cobalt catalysts. This modification can be evaluated by alteration of the catalyst acidity. Mn is an acidic promoter, whereas K is an alkaline promoter. Therefore, the addition of Mn and K as single and double promoters can be applied to enhance Co/&#947;-Al2O3 catalyst performance. <br /> <br /> Co-K/&#947;-Al2O3, Co-Mn/&#947;-Al2O3 and Co-K-Mn/&#947;-Al2O3 were prepared by incipient wetness impregnation. K or Mn loading for single promoted catalysts were varied into 0.5%, 1% and 1.5% w/w. The loaded amount of K and Mn on Co-K1.5-Mn0.5 catalyst were referred to the largest &#945; respectively, while at Co-K1.2-Mn0.8 was based on the largest C5+ yield. The XRD results showed the crystallites size of Co is in the range of 8.01-10.22 nm. Mn addition decreased Co crystallites size. BET and BJH method exhibited the impregnation process reduced surface area and pore volume. Pore size of the entire catalysts was 6.72 ± 0.06 nm. TPD results confirmed K decreased the total amount and strength of acid sites of the catalyst, whereas the addition of Mn only increased the acidity of the catalyst. Activity test has been performed at fixed-bed reactor on 250°C, 20 bar and syngas flow rate 1500 mL/h. The C5+ yield of Co-K1.2-Mn0.8 catalyst was 0.199 g/(gcat.h).<p align="justify">