Patent attributes
A continuous process for treating a lignocellulosic feedstock is provided. This method comprises pretreating the lignocellulosic feedstock under pressure in a pretreatment reactor at a pH between about 0.4 and about 2.0. One or more than one soluble base is added to this pressurized, pretreated feedstock after it exits the pretreatment reactor to adjust the pretreated lignocellulosic feedstock to an intermediate pH of between about pH 2.5 to about pH 3.5. This pressurized, partially-neutralized feedstock is then further processed at the intermediate pH. This may include flashing one or more than one time at the intermediate pH. The pH of the pressurized, partially-neutralized feedstock may then be adjusted with one or more than one base to produce a neutralized feedstock having a pH between about 4 and about 6. Prior to adjusting the pH to between about 2.5 and about 3.5, the pressurized, pretreated feedstock truly be partially depressurized.
