Lifecycle analysis for liquid biofuels: science, policy and politics

Liquid fuels from renewable biomass can make an important contribution toward decreasing carbon dioxide emissions from fossil petroleum, especially for end uses in the transportation and industry sectors where direct electrification is not yet feasible. However, industrial-scale production of biofuels within an energy economy still dominated by fossil fuels implies that substantial greenhouse gas emissions inevitably remain. In this presentation, we will consider key elements that determine the lifecycle carbon emissions associated with biofuel manufacturing, with particular focus on renewable diesel production in British Columbia and West Coast US states that have enacted aggressive low carbon fuel standards (LCFS).

LCFS laws in these jurisdictions have been remarkably successful in incentivizing substitution of petroleum diesel with biomass-derived renewable diesel, but this very recent progress has already begun to raise questions regarding the future of the industry. In particular, limitations in feedstock supply and financial incentives to expand production will increase pressure to convert food crops to energy production, amplifying challenging questions around the issues of indirect land use change and social equity. Careful dissection of the components of the LCA for renewable diesel sheds light on the key tradeoffs implicit in further growth of the industry, including the "food vs. fuel" debates that so often influence the development of agricultural policy in the US and abroad.