A SUPPORTED TITANIUM BASED CATALYST FOR IN-SITU HYDROGEN SULPHIDE DESULPHURIZATION AND CARBON DIOXIDE METHANATION REACTION IN NATURAL GAS

Abstract

Malaysian crude natural gas contains various gases components including methane (40-50%), ethane (5-10%) and propane (1-5%). However, this crude natural gas also contain H₂S (1–5%) and CO₂ (20-30%) which have the ability to corrode carbon steel used in the natural gas pipeline system and material in the processing plant. Fe³⁺/Zn²⁺/Cu²⁺/Ti⁴⁺/Al₂O₃ with the ratio 0.1:0.1:0.8:1 was prepared to produce the best catalyst for in-situ reaction of  H₂S desulphurization and CO₂ methanation. This catalyst was produced via modified sol-gel and impregnation methods and was calcined at 400 °C for 5 hours. The results of catalytic activity testing for the Fe³⁺/Zn²⁺/Cu²⁺/Ti⁴⁺/Al₂O₃ showed H₂S desulphurization percentage of 100% and 0.9% methanation at aworkable plant reaction temperature of 100 °C. This catalyst also had the lowest H₂S adsorption with 1.9% at the range of room temperature to 40 °C and it also could oxidize the highly concentration of H₂S with 94.3% at the low temperature of 40^oC. Importantly, this catalyst could be regenerated via heating at 200 °C for 3 hours under compressed air flow at the rate of 100 mL min^-1. The XRD analysis only showed the present three peaks due to cubic phase of γ-Al₂O₃. The Ti, Cu, Zn and Fe elements present in the catalyst matrix system were presumably to be homogeneously dispersed on the surface of alumina support besides their presence in very low concentration. The SEM micrograph showed that this catalyst had homogeneous size particles.