Evaluating CO2 capture technologies for retrofit in cement plant

摘要

The retrofitting of two different CO2 capture technologies to an existing cement plant has been evaluated technically. The two technologies considered are amine based post-combustion and oxy-combustion. These two technologies are chosen because amine based capture is considered to be closest to commercialization, while oxy-combustion is considered to be a possible future path for the cement industry. Amine based post-combustion CO2 capture is an energy demanding process, therefore different energy supply options were considered. This included utilization of waste heat from the cement exhaust gas and the addition of a dedicated natural gas fired energy plant. The energy plant generated more CO2 which also had to be captured resulting in a larger CO2 capture plant compared to one where only the CO2 from the cement is captured. Evaluations of the electricity consumption of oxy-combustion technologies identified the CO2 compression and purification unit (CPU) as a major consumer. The amount of air in-leakage becomes an important factor for the CPU performance. Air in-leakage should be kept to a minimum to ensure effective CO2 capture when retrofitting the cement plant with oxy-combustion CO2 capture.