A new study by researchers with the University of Pennsylvania provides a comprehensive analysis of the current state of industrial heating, and discusses the possibilities and limitations of decarbonization.
While personal efforts toward decarbonization, like switching from a gasoline-fueled vehicle to an electric vehicle, are beneficial in that goal, efforts to decarbonize major industries will have a much larger impact. One industry, according to the Penn report, is uniquely suited to make an attempt at decarbonization, but serious economic challenges must be overcome for viability.
The report analyzes heating processes used in the cement industries of California and Pennsylvania, which are major hubs of cement production, and argues that they are uniquely suited to adopt decarbonization strategies.
Cement-making is a highly emissive process. Carbon dioxide and other greenhouse gases (GHGs) are released not only from the fueling of furnaces to heat kilns needed for cement production, but also from the materials heated within those kilns. According to the study, emissions from cement production reached 40.3 metric tons of carbon dioxide equivalent (MtCO2eq) in 2018. Though less emissive than other heavy industries like steelmaking and coke production, decarbonizing the cement industry alone would abate a significant amount of GHGs from entering the atmosphere.
Two decarbonization technologies presented in the report that can apply to cement processing tackle emissions from both previously mentioned processes. To abate emissions generated from the burning of fossil fuels needed to heat the kilns used in the process, the authors present the use of oxygen as a fuel, or oxyfuel. An oxyfuel system replaces the air within a kiln with pure oxygen, which is more efficient in heating than atmospheric air. The emissions released through the oxyfuel process are collected, and can be used as a feedstock for other kilns, thus reducing or eliminating emissions from the kiln-firing part of the process.
For other emissions within the cement industry, the authors suggest the use of carbon capture and sequestration (CCS). CCS is an umbrella term that encompasses several different technological processes to capture and store atmospheric carbon. In this case, carbon emissions would be harvested before it can be released into the air, and then stored in deep underground geological formations. California and Pennsylvania are uniquely equipped to develop CCS, according to the study, due to the geological formations beneath each state.
Though possible, adoption of such technologies are unlikely without economic incentives for the industry to do so given the current costs associated with the transformation. The federal infrastructure bill approved last year contains funding for carbon capture development, as well as development of hydrogen as a clean energy source for heavy industry, such as cement and steelmaking. Rapid advancements and scaling of the technologies will be needed in order for them to be adopted as cost-effective alternatives.