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.