Polygeneration system with CO2 capture integrated with black liquor gasification in pulp and paper mills to produce methanol and power

Based on the KAMa reference pulp and paper mill, polygeneration systems integrating a black liquor gasifier with CO2 captured by means of oxygen-fuel combustion and Selexol pre-combustion are introduced and studied. Compared with the reference system the polygeneration system produces additional 73.5MW methanol while reducing electricity product of 11.2MW with the investment incremental of 8.6%. The energy penalty due to CO2 capture and compression is 0.46 MJ electricity per kg CO2 avoided for oxygen-fuel method at a cost of 25.9$ /tonne CO2. However, the energy penalty can reach 1.33 MJ Methanol per kg CO2 avoided in the Selexol pre-combustion CO2 capture process at a cost of 48.6$ /tonne CO2.