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.