2. Overview of CO₂ Capture Technology

Until cost-effective alternative energy sources are available, it is necessary to capture harmful waste gases at the source (i.e., smoke stacks). CO₂ gas can be captured prior to combustion, through an oxyfuel combustion stage, or after combustion. Currently, the most common way to separate carbon dioxide gas is through an amine-scrubbing system in post-combustion scenarios; however, this method can be costly and byproducts are harmful to the environment. For this reason, absorbents, adsorbents, membranes, gas hydrates, and chemical looping processes are considered as methods for CO₂ gas capture. Industries such as iron and steel and cement industries can also incorporate CO₂ separation and capture technologies. Once CO₂ is captured, it can be transported through pipelines and stored in geological formations and ocean reservoirs.