| dc.description.abstract | Using CO2 capture to extract CO2 from large point sources (like iron-steel industries, coal-fired power plants, etc.) is a promising way to cut CO2 emissions. In general, the CO2 capture process is thought to be a remedy for the global emission issues that the world is currently experiencing.
The use of potassium carbonate (K2CO3) as a solvent to extract CO2 from flue gas is investigated in this work. Fortum's waste-burning plant in Klemetsrud, Norway is used as an example in this study. A customized model was created using Aspen HYSYS V.14 to fit the specific features of the supplied flue gas. Cost estimation and dimensioning were based on this model.
One of the key objectives was to compare the K2CO3-based model with a previously developed MEA (monoethanolamine) model from a group project, both targeting a CO2 removal efficiency of 90%. Cost estimations for base case were conducted using the Aspen In-plant Cost Estimator and the EDF method.
To assess the effect of different flue gas inlet pressures on the process performance and expenses, a sensitivity analysis was carried out. Operating expenditure (OPEX) was automatically computed by modifying equipment sizes within the simulation's OPEX spreadsheet, whereas capital expenditure (CAPEX) was determined based on the total equipment costs. The annual CAPEX and OPEX were approximately 25.4 and 35 million EURO per year, respectively.
Compressors were found to be the costliest piece of equipment in the base case, accounting for 87% of the annualized CAPEX. Around 84% of OPEX was attributed to electricity consumption, with compressor usage accounting for the 98% of the electricity cost.
According to the sensitivity analysis, there was a decrease in CAPEX, and OPEX when the inlet pressure was lowered from 26 bar to 18 bar. Nevertheless, this also resulted in a marginal drop in CO2 capture costs from 148 euros per ton of CO2 to 147 euros per ton of CO2, as well as a decline in CO2 removal efficiency from over 90% to roughly 85%.
A comparison between the K2CO3 process and the MEA process revealed that the K2CO3 process, with compression stages included, is significantly more expensive. This is in line with results from literatures. However, if high-pressure flue gas is available, eliminating the need for compression, the annualized CAPEX and OPEX could be significantly reduced, making the K2CO3 process a more cost-effective option. | |
