Total (sum of monomeric and oligomeric) xylan yield (fraction of xylan originally present in biomass feedstock released as xylose) from dilute acid pretreatment alone (hollow symbols) and pretreatment followed by enzymatic hydrolysis (filled symbols) as a function of pretreatment temperature. (a) Corn stover (b); poplar; (c) switchgrass; (d) biomass sorghum. All pretreatment experiments were performed with 3 g (dry weight) biomass, 30 mL of 1% sulfuric acid with a 7-minute heating time and a 6-minute static time in a 66-mL zirconium cell. All enzymatic hydrolysis experiments were performed at 10% solids using an enzyme loading of 40 mg/g biomass. For all feedstock types the maximum xylose yield occurs at a temperature of 150°C or 160 C, respectively. However, the maximum difference between the highest and lowest maximum yield values (corn stover and poplar) occurs at a reactor temperature of 130°C.