H2S SELECTIVE ABSORPTION WITH ALKANOLAMINE SOLUTION

• Main Author: Ruth Dorkas, Gabrielle
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/65498
• Institution: Institut Teknologi Bandung

Natural gas is a type of fossil fuel and is widely used for individual usage, transportation, and industry. Acid gas, such as CO2 and H2S, contained in freshly obtained natural gas from the well needs to be removed because it is corrosive, toxic, can reduce the heating value of natural gas, and can damage the environment if it is freely disposed. Removal of acid gas is conducted in the Acid Gas Removal Unit (AGRU). The acid gas will be processed in the Sulfur Recovery Unit (SRU) to convert the toxic H2S to valuable elemental sulfur. Prior to the recovery process, it is required to increase concentration of H2S in the acid gas in the Acid Gas Enhancement Unit (AGEU) commonly using alkanolamines. This research aimed to compare the selective absorption to H2S of several alkanolamines and to determine the optimum flow rate ratio of solvent to gas (L/G). Criteria that are evaluated are H2S removal ability, CO2 slip, absorption selectivity factor to H2S, and regeneration performance. The types of solvent used were MDEA 47%-w, aMDEA 45%-w (MDEA 40.5%-w + Piperazine 4.5%-w) dan mixed of MDEA 48.5%-w + H2S Activator 1.5%-w. The solvents were fed at 0.232 L/min according to the column hydrodynamics limitation, meanwhile the gas flowed at 4 - 5.4 L/min with 0.5%-mole H2S and 50%-mol CO2. Absorption was conducted in an atmospheric condition and temperature of 25°C. In this research, MDEA 48.5%-b + H2S Activator 1.5%-b at the L/G 0.0579 can be applied in the Acid Gas Enrichment Unit (AGEU) due to its H2S removal of 95%, slip CO2 38%, and selectivity factor of about 1.263. On the other side, MDEA 47%-b and MDEA 40.5%-b + PZ 4.5%-b solvent gave inferior selective performance with the optimum selectivity factor of 1.025 and 1.000, respectively, because of the high number of CO2 absorbed, so they are more suited to be applied in the AGRU. Optimum regeneration temperature is studied and obtained at 115°C resulting in CO2 mole fraction in lean amine if 0.0001 and regeneration efficiency of 100%.