CO2 Capture from Flue Gas by Amine Absorption; using HYSYS A Technical and Economical Analysis

Abstract

Global warming due to the emission of greenhouse gases from different sources; mainly from industrial sector is a severe environmental issue in this modern world. CO2 is the main constituent of greenhouse gases emitted from industries and playing a significant part in raising the atmospheric temperature. In developing countries emissions are expected to grow rapidly in next 15 years and surpass emissions of industrialized countries near 2018. Power plants are considered to be the major source for CO2 emission. In addition to power plants, industrial sources like cement plants, oil refineries, iron and steel plants, ammonia & hydrogen production plants, and natural gas processing facilities are also being considered for application of CO2 capture technologies. Active research work is being carried out and efforts are being made to establish and optimize the processes to capture CO2 from flue gas. Presently; amine absorption process has been reported as the most feasible and effective process for CO2 capture at large scale. By employing this process acid gas can be recovered efficiently with required purity. Choosing the right solvent is important because, the lower temperature for solvent regeneration lowers the energy cost of CO2 capture. In this research work amine absorption process for removal of CO2 from flue gas emitted from coal fired plant containing about 13% CO2 has been simulated and optimized using Amine Package in HYSYS 3.2. Optimization study has been carried out by simulating number of cases by varying pressure of solvent and feed gas. DEA as a solvent has been selected for use in comparison to MEA, since MEA is more corrosive and degradable solvent than DEA. Economical analysis has also been carried out according to standard methods and procedures described in literature. With CO2 removal of ≥ 90%, heat consumption is calculated to 3.57 MJ/kg CO2 removed, close to a literature value of 4.0 MJ/kg CO2. Calculated value of gas capturing cost is 1.60 $/MSCF or 30.70 $/ton of product. These values are well with in the range as reported in established processes for CO2 capture and also align with the relevant literature and research work.