HIGH EFFICIENCY ON CO2 REMOVAL IN NATURAL GAS WITH UCARSOL™ SOLVENTS

The present work evaluated a gas sweetening plant using amine solvents to remove CO2 in natural gas in order to get a sweet gas in ppm levels. The work was conducted using Dow Chemical’s proprietary simulator PROCOMP™. At this specific case study CO2 concentration is around 13% and the maximum specification limit is 100ppm. This very rigorous CO2 specification in treated gas is often required for liquefaction process, where gas must have all impurities removed prior to cooling. More specifically, carbon dioxide and water must be extracted upstream of liquefaction or they would cause damage to liquefaction facilities by freezing. The cooling of natural gas to -160o C allows it to be transported economically by reducing the volume by 600:1. The conversion of natural gas to its liquefied form allows for the transport of greater quantities. The simulation is conducted with a commodity solvent, Methyl diethanolamine and also with a formulated solvent UCARSOL™ AP-814 in order to check the performance in terms of CO2 removal, rich and lean loadings in the amine stream, and considering the same operational conditions like recirculation rate and heat duty in regeneration. Based on the results got for same conditions applied in both solvents, UCARSOL™ AP 814 removed most of the CO2, letting the sweet gas with 2.67 ppm of CO2 (molar fraction). Results obtained for MDEA generated a sweet gas with 2.8% of CO2. The removal of CO2 using UCARSOL™ AP 814 was 10,000 higher comparing to regular MDEA and proves the high selectivity for CO2 removal.