Should straw/stover be turned into syndiesel or ethanol?

Straw and corn stover can be used to produce ethanol by enzymatic hydrolysis and fermentation, or syndiesel by oxygen gasification and Fischer Tropsch (FT) reaction. FT has a higher processing cost and a higher energy yield of liquid transportation fuel. We analyze the cost of produced liquid fuel as a function of the field cost of biomass. At 80 $ t−1 (dry basis) a crossover point is reached. Below this value, the cost of producing energy as ethanol is lower; above this value, FT syndiesel is lower. However, the crossover point occurs at a very high field cost of biomass, more than 5.50 $ GJ−1, and ethanol plants are less capital intense than FT and hence have a smaller economic size. For both reasons ethanol is likely to be the preferred processing alternative.