Comparative assessment of industrial energy systems with negative CO2 emissions : Black liquor-based CHP with CO2 removal

This paper investigates power production and CO2 reduction potentials of alternative systems for black liquorbasedcombined heat and power production (CHP) in pulp mills. The impact of incorporating CO2 removal inthe CHP systems is analysed. Spent cooking liquor in chemical pulp mills is an important source of bioenergy.Biomass energy with CO2 removal and disposal can yield negative CO2 emissions because the CO2 disposedof comes from biomass - i.e. CO2 can be removed from the atmosphere on a net basis while energy needs aresustained. We compare heat, power, and CO2 balances of systems with (1) alternative CO2-removal options(2) different systems for CHP. In relation to (1) we study CO2 removal with or without enhancing the CO2removal through reacting carbon monoxide with water (water-gas shift). The study reveals that black liquorgasification CHP with CO2 removal and disposal is an effective approach for CO2 reductions from bothenergy and environmental points of view.QCR 20231113