- Oxygen Combustion in Cement Production

Abstract

Concrete is almost literally the backbone of society. Most infrastructure projects depend directly on concrete, making it the largest commodity, globally, after water. Cement, the binding agent in concrete, is produced in a high-temperature pyroprocessing facility and consumes a significant amount of heat as well as releasing large amounts of carbon dioxide (CO2). Ongoing scientific research into the effects of anthropogenic CO2 emissions has the potential to create a net zero carbon economy before the end of the century. Over decades, the rate of emissions should start to drop and gradually trend to less than 30% of current global emissions. In the near term, the focus of any emission reductions will be directed toward large, point source emitters, most prominently coal-fired power plants. Cement plants are included in this group and are the largest industrial emitter in terms of the number of facilities and total greenhouse gas emissions. The Intergovernmental Panel on Climate Change (IPCC) special report on Carbon Capture and Storage (CCS) estimated that cement manufacturing produces 932 Mt CO2 per year from fossil fuel use at 1175 facilities (Table TS.2, IPCC 2005).1 It should be noted that the IPCC only considered emitters in excess of 0.1 Mt of CO2 per year and does not include CO2 generated from the calcination of the raw meal (a mixture of calcite, silica, and oxides of iron and aluminum). The threshold is equivalent of a 300 t/day (tpd) clinker kiln, which is smaller than the vast majority of existing kilns.