The U.S. EPA is inviting comment on its analysis of the greenhouse gas (GHG) emissions attributable to the production and transport of jatropha oil for biodiesel, renewable diesel and other biofuels to qualify under the renewable fuel standard (RFS).

EPA says based on its analysis, the agency anticipates jatropha oil-based biodiesel or renewable diesel could qualify as biomass-based diesel or advanced biofuel under RFS, both of which require a 50 percent reduction in GHG emissions compared to petroleum diesel, if typical fuel production process technologies or process technologies with the same or lower GHG emissions are used.

EPA evaluated a number of scenarios but discuss two main ones in its notice. 

In the first scenario, EPA assumes that jatropha production will occur on grassland in southern Mexico and northeastern Brazil that is not currently being used for crop production or pasture use. The results from this scenario were varied but most were slightly to moderately lower than GHG emissions from soybean oil; one analysis under this scenario was higher than soybean oil.

In a second scenario, EPA considered the possibility that jatropha will be grown on land that would have otherwise been used for agriculture (crop production or grazing/pasture). The agency conducted two analyses within this scenario—one where it assumed that jatropha will displace crops, predominantly corn, in Mexico, and one where jatropha is grown on cropland in Mexico and on agricultural land in Brazil (with the model choosing what land to displace in Brazil). Various results under this scenario showed significantly lower GHG emissions than soybean oil, with some even negative. “The net GHG emissions in this analysis are negative primarily because jatropha sequesters more carbon than the cropland it displaces and the indirect emissions are relatively small because the displaced corn production is backfilled by higher yield producers (e.g., corn production in the United States),” the agency determined.