Absorption and Simulation of Carbon IV Oxide Recovery Plant with Monoethanolamine Solvent using Aspen HYSYS

Abstract

Carbon IV Oxide (CO₂₎ was extracted from a natural gas (NG) stream containing 8.7% carbon dioxide, 17.8% water, 73.4% nitrogen, 0.1886% oxygen, 0.0017% sulfur dioxide, and 0.0097% nitrox using monoethanolamine (MEA) solvent. The CO₂ is an acidic and greenhouse gas which may cause corrosion attacks on the pipelines, vessels and global warming when the concentration is accumulated appreciably, hence the need to free the natural gas from it. The process parameters were 500 tons per day flow rate, 150⁰C temperature, and 101.6 kPa pressure. Using ASPEN HYSYS, an optimization and technical parameter study was conducted for a CO₂ recovery process from mixture of gas of a natural gas liquefaction plant at different percentage recoveries (75%, 80%, 85%, 90%, 95%, and 99%). The procedure was based on the use of MEA solutions in an absorption/desorption process. Recovering more CO₂ from the NG than was initially present is the aim. Deviations of 3% and 10% and root mean square error of 0.5 and 1.5 from the validation of the simulation result with plant data show that, in contrast to earlier research, the simulation using Aspen HYSYS of V8.8 was able to extract 99% of the 8.7% CO₂ from NG. The models showed that CO₂ recovery was possible once pumps were installed inside the facility. The simulation result further showed that the overall cost of the recovery CO₂ plant including the cost of utilities, was obtained to be $19.629m.