June 6, 2007
Switchgrass-based ethanol produces fewer greenhouse gas emissions than corn, study says
Cambridge, Massachusetts – A new study by researchers at the Massachusetts Institute of Technology (MIT) says that ethanol derived from switchgrass offers a slightly better net energy value and produces significantly lower greenhouse gas (GHG) emissions than corn ethanol when the life cycle is studied.
The four cellulosic ethanol pathways assessed in the study all performed much better than the five conventional corn ethanol pathways studied; some of the corn ethanol showed little to no GHG improvement when compared to gasoline.
A scenario using corn ethanol produced in Georgia, traditionally a non-corn-producing state, resulted in the worst performances of any of the scenarios, due to increased fertilizer inputs, irrigation and lower crop yields.
The researchers extended the model to 2025 to project the performance of both corn and switchgrass ethanol and found that while corn ethanol showed some improvement using 2025 figures, it still significantly trailed switchgrass.