| dc.description.abstract | As a step towards net-zero emissions in the future, a CO2 capture facility is under construction at the cement plant Norcem in Brevik. This will reduce emissions by 400 000t/yr. To utilize waste heat from the cement production a waste heat recovery unit will be installed in the raw meal department, utilizing the available waste heat from the kiln preheater. With altered temperatures and flow rates, this report will seek to find the impact of these changes on the production capacity.
For normal WHRU operation, the production capacity should not be affected since the needed temperatures and flow rates are available. The challenge will be in controlling the pressures to reach the desired flow rates and the corresponding temperatures.
With the reduced water content in the flue gas from the preheater, the saturation temperature will be reduced. This will in turn allow for a reduction in the mill inlet temperature and recovery of an additional 1.92MW of heat. This is dependent on sufficient residence time for the raw materials to reach complete evaporation of water.
Further, the work has investigated the impact of ambient air leaking into the process and how the removal of this would impact the system. Results indicate that complete will cause a hot gas deficit and is therefore not an option. Partially sealing the system will allow for an additional 2.4MW of heat recovered during LA production. For STD the sealing will only cause increased outlet temperatures and no further heat recovery will be possible. | |
