Advanced Mineral Carbonation: An Approach to Accelerate CO₂ Sequestration Using Steel Production Wastes and Integrated Fluidized Bed Reactor

Abstract

Industrial pollution is the major source of global warming through emissions of greenhouse gases (GHG’s) like CO₂, CH₄, and NO₂, causing noticeable increasing in the world’s temperature. Mineral carbonation is a method of carbon capture and storage (CCS) through which CO₂ is sequestered with advantage of permanent sequestration and no need for post-storage surveillance and monitoring through stabilizing the reactive mineral wastes released from metal industries. This paper applied a simple and an inexpensive hydration process as a pre-treatment step for the carbonation of Ladle Furnace (LF) slag, one of the steel production by-products in UAE, followed by direct gas-solid carbonation in a new designed integrated fluidized bed reactor (FBR). About (10–15)% by weight of produced steel, alkaline solid residues were generated, based on the characteristics of the manufacturing process. The integrated FBR was designed to control the flow rate up to 50 l/min with step accuracy of 0.1 l/min, and temperature up to 200 °C through a double jacket electrical heater. Operating pressure can be adjusted up to 6 bars. All parameters are monitored by SCADA system. A mixture gas of 10% CO₂, balanced with air, was used to perform the carbonation process and evaluation the carbonation efficiency as well. A gas analyzer installed at the outlet of FBR was used to measure unreacted CO₂ gas after leaving the reactor, and calculate the amount of CO₂ captured accordingly. Results of analytical techniques like TGA and XRD emphasized the sequestration of CO₂ and show a high efficient carbonation process.