The effect of alternative fuels on calcium-looping

Abstract

Calcium-looping (CaL) is a promising post-combustion CO2 capturing technology, showing high compatibility with the cement industry. Nevertheless, this technology is still under development, and its implementation still leads to higher operating costs. Aiming cost reduction, the influence of using alternative fuels, commonly used in the kiln of cement plants, in the CaL calciner was studied in terms of key performance indicators, such as the amount of fuel needed, the carbonator’s heat duty, the air separation unit (ASU) energy consumptions, and the amount of CO 2 captured in the process. Thus, a CaL process was modeled using Aspen Plus, incorporating a carbonator model developed using Python. Different random compositions of petroleum coke, tire chip, waste-derived fuels, olive pomace, dangerous liquid residues, and cork residues were studied. It was concluded that the use of petroleum coke leads to lower fuel consumption and ASU consumption due to its higher heating value. However, the alternative fuels studied have advantages in terms of CO2 capture efficiencies and energy produced in the carbonator due to lower sulfur contents. Therefore, the sorbent flowrates would have to increase to obtain the same capture efficiency using petroleum coke, which would result in a higher process cost. Alternative fuels are promising in CaL and should be a topic for further studies.