Near-term deployment of carbon capture and sequestration from biorefineries in the United States.

Abstract

Capture and permanent geologic sequestration of biogenic CO₂ emissions may provide critical flexibility in ambitious climate change mitigation. However, most bioenergy with carbon capture and sequestration (BECCS) technologies are technically immature or commercially unavailable. Here, we evaluate low-cost, commercially ready CO₂ capture opportunities for existing ethanol biorefineries in the United States. The analysis combines process engineering, spatial optimization, and lifecycle assessment to consider the technical, economic, and institutional feasibility of near-term carbon capture and sequestration (CCS). Our modeling framework evaluates least cost source-sink relationships and aggregation opportunities for pipeline transport, which can cost-effectively transport small CO₂ volumes to suitable sequestration sites; 216 existing US biorefineries emit 45 Mt CO₂ annually from fermentation, of which 60% could be captured and compressed for pipeline transport for under $25/tCO₂ A sequestration credit, analogous to existing CCS tax credits, of $60/tCO₂ could incent 30 Mt of sequestration and 6,900 km of pipeline infrastructure across the United States. Similarly, a carbon abatement credit, analogous to existing tradeable CO₂ credits, of $90/tCO₂ can incent 38 Mt of abatement. Aggregation of CO₂ sources enables cost-effective long-distance pipeline transport to distant sequestration sites. Financial incentives under the low-carbon fuel standard in California and recent revisions to existing federal tax credits suggest a substantial near-term opportunity to permanently sequester biogenic CO₂ This financial opportunity could catalyze the growth of carbon capture, transport, and sequestration; improve the lifecycle impacts of conventional biofuels; support development of carbon-negative fuels; and help fulfill the mandates of low-carbon fuel policies across the United States.