The greenhouse gas emissions performance of cellulosic ethanol supply chains in Europe

Table 3 Mass balance and assumptions for reference-case enzymatic and dilute acid conversion processes.

^aFilter paper unit. ^bThe reference processes were adapted to include pentose fermentation using the following assumptions: the ethanol and CO₂ yield from pentose sugars was assumed to be 50%, reflecting the fact that the recovery of pentoses after pre-treatment is lower than for hexoses [17]; the solid fuel yield and process heat requirement was unaffected; the flow of chemicals was the same as the respective softwood enzymatic or dilute acid process. The reference processes were adapted to use straw as a feedstock using similar assumptions: the ethanol and CO₂ yield from hexose sugars was assumed to be the same as for the respective softwood enzymatic, or dilute acid, reference process; the solid fuel yield and process heat requirement was unaffected; the flow of chemicals was unaffected [5].