The influence of ferrous sulfate utilization on the sugar yields from dilute-acid pretreatment of softwood for bioethanol production.
By employing metal salts in dilute-acid pretreatment the severity can be reduced due to reduced activation energy. This study reports on a dilute-acid steam pretreatment of spruce chips by addition of a small amount of ferrous sulfate to the acid catalyst, i.e., either SO(2), H(2)SO(3) or H(2)SO(4). The utilization of ferrous sulfate resulted in a slightly increased overall glucose yield (from 74%