Completed Research
TEA of the CO2 Capture in Post-combustion Applications Using Chemical Solvents and the Blue H2 Production in the SMR-CCS Process Using Physical Solvents.
Rui Wang, PhD, 2024
(Thesis: University of Pittsburgh ETD)
As a greenhouse gas (GHG), CO2 has become one of the chief drivers of climate change primarily due to combustion of fossil fuels. Increasing CO2 emissions into the atmosphere is raising global temperature, leading to detrimental impacts on humans and the environment. These include, increasing frequency and intensity of extreme heatwaves, hurricanes and floods, rising sea levels, increasing conflicts among nations due to migration arising from resources scarcity, and deteriorating human physical and mental health. Therefore, reducing CO2 emissions is the most crucial step in mitigating the catastrophic impacts of climate change. Existing technologies for CO2 capture from energy systems and industrial sectors include post-combustion, pre-combustion and oxy-combustion.
The objectives of this study were to develop models in Aspen Plus V.12.1 and perform techno-economic analysis (TEA) for the CO2 capture process in two post-combustion industrial power plants (Longview, WV and Wolverine, MI) using five chemical solvents; and for a novel steam methane reforming-carbon capture and storage (SMR-CCS) process to produce blue hydrogen using thirty-six physical solvents. To achieve these objectives, the overall process block flow diagrams and constraints were created and the solvents’ physico-chemical properties, reaction kinetics and rates, and water retention were determined. The process hydraulics and mass transfer characteristics were also calculated. For the post-combustion processes, the capital expenditure (CAPEX), operating expenditure (OPEX) and the levelized cost of carbon capture (LCOC) were calculated for five chemical solvents. For the novel SMR-CCS process, the CAPEX, OPEX and LCOC of the CO2 capture unit and the levelized cost of blue hydrogen production (LCOH) were calculated for thirty-six physical solvents.
The Aspen Plus V.12.1 simulation results indicated the following: (1) Potassium glycinate was the most economically feasible chemical solvent for the post-combustion CO2 capture at LCOC of $26.53/ton CO2 captured, due to its unique ability of phase separation and the formation of potassium bicarbonate (KHCO3) nanomaterials which were sold to offset the overall process cost. (2) 1AB-DECAM was the most economically feasible physical solvent for SMR-CCS process at LCOH of $0.93/kg H2 produced, due mainly to its high CO2 solubility at low partial pressures (< 5 bar).