Carbon negative oil: A pathway for CO2 emission reduction goals

Abstract

There is a carbon sequestration benefit to the ethanol manufacturing process if the CO2 that is created in the fermentation process in an ethanol plant is geologically stored by an enhanced oil recovery (EOR) project. In order to recover one barrel of oil using CO2-EOR, an equal or greater amount of CO2 must be sequestered in order to recover the oil (∼1.0–2.5 tonnes of CO2 are stored for each tonne of CO2 emissions resulting from combustion of the recovered oil). The oil produced from a CO2-EOR sequestration project is therefore either carbon neutral or carbon negative if the CO2 is sourced from the fermentation emissions from an ethanol plant. The 40.3 million metric tonnes of CO2 fermentation emissions vented during the production of 53.4 million liters of ethanol per year in the U.S. could result in production of 40–100 million barrels of carbon negative oil annually. A carbon value chain (CVC) based on carbon credits could incentivize the construction of a CCS infrastructure in the United States that begins with the capture of corn ethanol CO2 fermentation emissions. Utilization of biofuel fermentation emissions worldwide in bio-CO2-EOR sequestration projects would help achieve global CO2 emission reduction goals.