Towards Efficient Bioenergy Systems: Understanding the Role of Soil Sequestration, Supply Chain Design, and Carbon Capture

Abstract

Bioenergy with carbon capture and storage (BECCS) can produce carbon-negative biofuels from dedicated cellulosic biomass to mitigate global warming; however, the economic and environmental performance of a BECCS system is highly sensitive to carbon incentives and the supply chain (SC) network. Because dedicated bioenergy crops have yet to be planted, there is an opportunity to simultaneously design the SC and choose crop locations that balance the tradeoffs among transportation costs, emissions, biomass yields, and soil carbon sequestration. At the biorefinery, alternative pretreatment and conversion methods lead to different ethanol yields and relative carbon flows among point sources of CO 2 emissions. We present an integrated mixed-integer optimization model for the biofuel SC with a detailed biorefinery model considering CCS that can be used to study the economic and environmental tradeoffs between (i) high resolution SC design and operation, (ii) upstream spatially explicit carbon sequestration in soils by dedicated bioenergy crops, (iii) biorefinery design and operation, and (iv) downstream CCS technology selection and operation. We present a case study with, critically, realistic crop, economic, and environmental data in the US Midwest to explore the effects of key system parameters on the cost and GHG balance of the entire system, and the associated changes in SC and biorefinery design and operation.