For consistency in analytical and experimental work, a framework document was established early in the project. This document is a general knowledge basis about cement plant operation with information relevant for CCS related research.
A techno-economic evaluation, as well as a retrofitability analysis, was carried out for the CEMCAP Technologies, i.e. oxyfuel, CAP, MAL and CaL (tail-end and integrated configuration), with MEA as reference. The techno-economic evaluation was based on process simulations, with input from experimental research. The main outcomes of the analytical work were:
• CEMCAP technologies generally outperform MEA regarding energy performance.
• Cost of clinker increases with 49-92% when the technologies are implemented in a reference cement plant under base case conditions. Cost of CO2 avoided (excl. CO2 transport and storage) lies between 42 €/tCO2 (oxyfuel process) which is approximately halved compared to MEA, and 84 €/tCO2 (MAL process), which is on the same level as MEA.
• In the techno-economic evaluation the oxyfuel technology seemed most promising, with the lowest CO2 avoided cost in the base case, followed by the calcium looping technologies. Results however depend on economic parameters, that vary over time and with location.
• Post combustion technologies are the most easy to retrofit – in particular MEA. The more integrated technologies (oxyfuel and integrated CaL) are assessed as more challenging. No retrofit showstopper was identified for any technology.
• The CEMCAP cost evaluation excel model is available online and can be used for plant-specific evaluations.
Post-capture CO2 management options for the cement industry were evaluated. It was found that CO2 utilization (CCU) always should be considered in combination with storage (CCS), as the realistic CO2 fraction to utilize from in a cement plant is expected to be lower than 10%. High added-value products may lead to positive business cases, but the usable amount of CO2 will be strongly limited by the product’s market. Further, the degree of sustainability of CCU (as opposed to CCS) is greatly dependent on the CO2 footprint of the product being displaced by a CO2-derived product.
Experimental research was carried out for three oxyfuel cement kiln components (burner, calciner and clinker cooler) and for CAP, MAL and CaL:
• Results from a downscaled burner tested in a 500 kWth pilot facility under relevant industrial oxyfuel conditions were used to validate models and simulate oxyfuel combustion in a large scale rotary kiln. It was concluded that the tested burner design is suitable for oxyfuel operation.
• Calcination experiments in a 50 kW electrically heated entrained flow reactor indicate that an oxyfuel calcination degree comparable to that of air calcination can be achieved, with temperature increase of around 60 °C.
• An oxyfuel clinker cooler prototype was installed at a cement plant, and clinker cooling under oxyfuel conditions was performed. No negative impact on clinker quality or cement strength was observed.
• CAP pilot-plant tests were carried out for absorber, direct contact cooler (DCC), and water wash units, confirming that the CAP can be adapted to cement plant flue gas capture with only minor process modifications and lower energy penalty than for coal-fired power. SOx levels out of the DCC can be reduced to negligible levels.
• For the MAL, two polymeric membranes were tested in lab, and verified that one membrane complied with the CO2 concentration required for subsequent liquefaction. Pilot-scale testing of CO2-liquefaction verified the efficient separation and purification of a membrane permeate gas.
• For CaL, operational parameters were screened in a 30 kW test facility. Tail-end CaL was demonstrated in industrial relevant conditions in a 200 kW pilot facility. Building on CEMCAP research, the promising but less mature integrated CaL concept is being further developed in the H2020 CLEANKER project.
The CEMCAP website has been continuously updated. CEMCAP has been on twitter (@cemcap_co2), and published newsletters and blog posts.
Three joint CEMCAP/ECRA workshops were arranged with focus on knowledge transfer between the consortium and the cement industry. The third workshop, co-organized with the CLEANKER project also included knowledge transfer towards policy makers and NGOs.
