In Illinois, today many biofuel refineries operate for only seven months each year, turning freshly harvested crops into ethanol and biodiesel. When supplies run out, biorefineries shut down for the other five months. However, according to recent research, dual-purpose biofuel crops could produce both ethanol and biodiesel for nine months of the year–increasing profits by as much as 30%.
A paper published in Industrial Biotechnology simulated the profitability of Plants Engineered to Replace Oil in Sugarcane and Sweet Sorghum (PETROSS) with 0%, 5%, 10%, and 20% oil. They found that growing sorghum in addition to sugarcane could keep biorefineries running for an additional two months, increasing production and revenue by 20-30%.
Today, PETROSS sugarcane produces 13% oil by dry weight, 8% of which is the kind of oil used to make biodiesel. At 20% oil, sugarcane would produce 13 times more oil–and six times more profit–per acre than soybeans.
A biorefinery plant processing PETROSS sugarcane with 20% oil would have a 24% international rate of return–a metric used to measure the profitability of potential investments–which increases to 29% when PETROSS sorghum with 20% oil is processed for an additional two months during the sugarcane offseason.