Large scale application of carbon capture to process industries – A review

Carbon capture (CC), along with the efforts to reduce carbon emissions at the source, is a major action toward the mitigation of climate change and global warming due to emissions of greenhouse gases (GHGs). Carbon emissions amount to 36.3 Gt-CO₂ in 2021 from 31.5 Gt-CO₂ in 2022, with a drop of about 1.5 Gt-CO₂ in 2020 relative to 2019 due to the COVID-19 pandemic. The carbon emissions originate from heat and power, transportation, process industries, and residential activities constitute 47.7, 24.9, 18.9, and 8.5% of the total emissions, respectively. The process industries represent the second large-scale point-source of carbon emissions next to heat and power. Additionally, the process industries have high-intensity carbon emissions up to 0.6–0.8 t-CO₂/t-cement, 1.4–2 t-CO₂/t-steel, and 2.7–99.2 kg CO₂/bbl, with flue gas streams having high CO₂ concentration up to 30%. In comparison to 0.4 t-CO₂/MWh and 3–16% CO₂ in the flue gas from heat and power facilities, these process industries present a highly effective target for CC application. This work reviews and critically discusses the large-scale application of CC to different process industries, namely, cement, iron and steel, oil refinery, and chemicals. CC can be achieved by three main approaches, i.e., post-combustion, pre-combustion, and oxyfuel combustion. Post-combustion and chemical-looping are the common CC approaches utilized in process industries, with the first being widely applied due to its ease of incorporation, and the latter is commonly used in the cement industry. CC with the capacity in the range of 0.4–2 Mt-CO₂/yr is planned for cement plants relative to current capacities of 75 kt-CO₂/yr. Similarly, CC capacity up to 0.8 Mt-CO₂/yr has been integrated into iron and steel plants, in which captured CO₂ is utilized for enhanced oil recovery (EOR) applications. In the oil and gas industry, CC has been widely utilized, in the context of gas purification, being an essential gas processing unit, with CC capacities up to 1.4 Mt-CO₂/yr, and plans to reach 4 Mt-CO₂/yr. CC cost is the main challenge for the widespread implementation of CC in process industries with a wide range of reported costs of USD9.8-250/t-CO₂ depending on the process industry and the CC technology used.