Effect of sodium hydroxide pretreatment on physicochemical changes and enzymatic hydrolysis of herbaceous and woody lignocelluloses

NaOH pretreatment is one of leading technologies for pilot-scale production of cellulosic fuel ethanol. It has two obvious features: low-energy input which is good for its practical application and high wastewater generation which makes it cost too much to avoid environmental pollution. As the methods developed for solving pollution from wastewater, the effect of NaOH pretreatment on enhancing bioconversion of various feedstocks should be evaluated. This study investigated the influence of NaOH pretreatment on enzymatic hydrolysis of herbaceous biomass, softwood and hardwood based on their physico-chemical changes. After NaOH pretreatment, the lignin removal and changes in chemical groups and microstructure of herbaceous biomass were more obvious than those of softwood and hardwood. NaOH pretreatment had significant improvement on enzymatic hydrolysis of herbaceous biomass, and different NaOH-treated herbaceous lignocelluloses had different enzymatic hydrolysis efficiencies. NaOH pretreatment is more applicable for improving bioconversion of herbaceous biomass than softwood and hardwood.