Can corn stove bioethanol production substantially contribute to China's carbon neutrality ambition?

Abstract

China has posed a great ambition for carbon neutrality by 2060. Bioethanol production is expected to contribute to this target. Corn stover (CS), which is highly productive but underutilized, is an attractive feedstock for bioethanol. We collected provincial data of corn production and CS utilization over 2010–2019 to predict the bioethanol potential and carbon conversion factor. In an ideal situation, bioethanol can amount to 40.3 Mt, which displaces 4.4% of the total national petroleum use in 2019. However, in energy sector, the CO2 reduction of bioethanol substitution was almost offset by the CO2 emission from energy consumption for bioethanol conversion. The application of by-product can provide a GHG emission abatement of 77.6 Mt CO2 eq and input savings of 23.9 billion RMB nationally. Overall, GHG emission can be reduced by over 170 Mt CO2 eq annually. These findings will help policy-makers reconsider the utilization of CS to achieve carbon neutrality.