CO2 Capture in Pulp and Paper Mills – Opportunities for Chilled Ammonia Absorption

Other conference contribution, 2008

Capturing CO2 from flue gases using the chilled ammonia absorption process shows much promise due to the low energy demand for the regeneration of the absorbent. One of the key features in the original process is the high pressure in the regenerator. In this paper it is investigated how the pressure in the regenerator can be varied in order to facilitate the use of excess heat from the mill for the regeneration. However, a lower pressure causes an increase in the electricity consumption. Several configurations for both market pulp mills and integrated pulp and paper mills are investigated here. The effect on the fuel and electricity balance is examined and the avoidance cost is calculated for each configuration. The results show that in market pulp mills the use of excess heat does not lead to a reduction in avoidance cost, since the energy savings are compensated by the increase in electricity consumption. For the integrated pulp and paper mill configurations the integration is more advantageous. The avoidance cost can be reduced by up to 15-20 %.