Motor fuel production integrated with pulp mills – CO2 balance and oil use reduction for solid biomass gasification and black liquor gasification alternatives

We study biomass-based motor fuel production integrated with pulp and paper mills and calculate oil use and CO2 emission balances. We compare two different processes – (1) integration of solid biomass gasification and FT diesel synthesis with a mill and (2) black liquor gasification (BLG) and methanol synthesis. CO2 emission and oil use balances are calculated and compared to alternative uses of biomass. We conclude that motor fuel production integrated with pulp mills is a more efficient option than stand-alone production of motor fuels. However, CO2 emissions can be more efficiently reduced if biomass replaces coal. BLG and solid biomass gasification have high system efficiencies. In a modern mill with low steam demand, the integration potential for solid biomass gasification is limited. If the studied systems are expanded with stand-alone production of fuel, so that the systems produce the same amount of motor fuel per t pulp, the BLG system has higher system efficiency due to the larger integration potential per t pulp.