Multi-aspect evaluation of integrated forest-based biofuel production pathways: Part 2. economics, GHG emissions, technology maturity and production potentials

Abstract

Promoting the deployment of forest-based drop-in and high blend biofuels is considered strategically important in Sweden but many aspects of the overall performance of the foremost production technologies are as yet unexamined. This paper evaluates the technology maturity, profitability, investment requirements, GHG performance and Swedish biofuel production potential of six commercially interesting forest-based biofuel production pathways.Significant heterogeneity in technology maturity was observed. Lack of technical demonstration in industrially representative scales renders the liquefaction-hydrotreatment route for drop-in biofuels less mature than its gasification-catalytic upgrading counterpart. It is a paradox that short-term priority being accorded to pathways with the lowest technology maturity. Nth-of-a-kind investments in (a) gasification-based methanol, (b) hydropyrolysis-based petrol/diesel, and (c) lignin depolymerization-based petrol/diesel were profitable for a range of plant sizes. The profitability of pulp mill-integrated small gasification units (<100 MW) goes against the common perception of gasification being economically feasible only in large scales. New low-cost options for debottlenecking production at recovery boiler-limited kraft mills appear worth investigating. GHG emission reductions ranged from 66 to 95%; a penalty was incurred for high consumption of natural gas-based hydrogen. Swedish biofuel production potentials ranged from 4 to 27 TWh/y but a more feasible upper limit is 12–15 TWh/y.