Design of Contactor Vessel for CO2 absorption from Natural Gas at Reserves using FLUENT

Natural gas (NG) is the most important energy source in various sectors and industries not only for power generation, but also as a primary feedstock for chemicals, plastics and fertilizers. Due to high demand of natural gas as an energy source, the explorations of natural gas that contain more than 30 percent of CO2 become necessary. As CO2 has been the major global warming contributor to the earth which also degrades the quality of natural gas and causing corrosion in refinery, this project aims to propose a new absorption system that uses methyethanolamine (MEA) to pre-treat at the source and lower the CO2 content before it enters the refinery. CO2 is treated with MEA along the height of contactor vessel and the absorption rate is measured at temperature of 30oC with the pressure range from 1 to 80 atm. This new absorption system is developed to remove 6 to 10 percentof CO2 from natural gas stream i.e. the CO2 content is reduced to 20% before transporting the natural gas to the amine treating unit. The work investigates the effect of operation pressure and gas and solvent velocities on CO2 concentration. The pressures used are 1, 10, 50 and 80atm and the velocity of gas are 6 and 28m/s with solvent superficial velocity of 0.016 and 0.055m/s. Studies shows that with the increase in operation pressure and solvent velocity directly increases the CO2 removal efficiency. This work introduces a feasible integration of an absorption system to remove CO2 at the NG reserves.
Keyword: computational fluid dynamic (CFD), reactive absorption, immobilized aminated resin, contactor design, CO2 absorption