CO2 capture in industries and distributed systems: possibilities and limitations

Abstract

CO2 capture and storage (CCS) is considered an important option to reduce greenhouse gas emissions. Large scale centralized power plants have been the main research focus of CCS, but the potential of CCS in the industry and petroleum refineries is also significant. Moreover, a large transition from centralized power generation to distributed generation (DG) may be seen in the future. If stringent CO2 emissions reduction is needed, DG systems will have to consider options that enable large CO2 emissions reduction, such as CCS. In this context, this thesis investigates the technical and economic performance of CO2 capture in industries and distributed energy systems for the short-mid term future (ST/MT) and the long term future (LT). The techno-economic assessment and comparison of CO2 capture technologies was performed for iron and steel, cement, and refineries and petrochemical sectors. The assessment is based on an extensive literature review, covering studies from both industries and academia. Key parameters, e.g. capacity factor, energy prices, interest rate, economic plant lifetime, CO2 compression pressure, and grid electricity CO2 intensity, were standardized to enable a fairer comparison of technologies. In the iron and steel sector, the results indicate that a cost of 40-65€/tCO2 avoided at a CO2 avoidance rate of 0.7-0.8tCO2/t hot rolled coil (40-45% of the total carbon input to the plant) are possible in the ST/MT. In the LT, advanced add-on capture technologies may not offer significant economic advantages over conventional ones. Instead, advanced steelmaking technologies will incorporate CO2 capture as part of production efficiency improvement while achieving significantly lower steel production costs compared to existing technologies. In the cement sector, 65-70€/tCO2 avoided at a CO2 avoidance rate of 0.6tCO2/t clinker (60% of onsite emissions) are possible in the ST/MT. In the LT, the costs may be reduced to 25-55 €/tCO2 avoided, but the CO2 avoidance rate may be somewhat lower. For petroleum refineries and petrochemical sectors, 50-60€/tCO2 avoided at CO2 avoidance rate of about 80% can be achieved in the ST/MT. In the LT, advanced oxyfuel CO2 capture with an integrated power plant may enable 30€/tCO2 avoided or lower. Regarding CO2 capture in distributed energy systems, the energy efficiency reduction due to CO2 capture (energy penalty) in the ST/MT vary significantly by fuel type, energy system type and its application, ranging from 11% to 33%. CO2 avoidance costs are around 40-140€/tonne for systems larger than 100 MWLHV (fuel input) and 50-160 €/tonne for 10-100MWLHV. In the LT, the CO2 capture energy penalty may be reduced to around 4-9%. CO2 avoidance costs are around 10-90 €/tonne for systems larger than 100MWLHV, 25-100€/tonne for 10-100MWLHV and 35-150€/tonne for 10MWLHV or smaller. CO2 compression and distributed transport costs may become a bottleneck mainly at smaller scales (more than 50€/tCO2 transported for systems with 1MWLHV natural gas input or smaller). The results indicate that any industrial and distributed CO2 emission sources should be included for the consideration of CCS both in the short and the long term, but the technical and economic feasibility is more case-dependent than in the centralized power sector.