Enhancement of bio-jet fuel production from corncob by iron ion-catalyzed hydrogen peroxide pretreatment

Developing efficient and green pretreatment pathways is of great significance for the production of biofuels. The purpose of this work is to evaluate that iron-ion catalyzed hydrogen peroxide (Fe-HP) pretreatment can be used for the enhancement of bio-jet fuel production using corncob as a typical lignocellulosic biomass. Typically, the Fe-HP pretreatment was conducted under the following pretreatment conditions: H2O2 concentration of 5.0 wt%, iron ion concentration of 400 ppm, biomass loading of 10 wt%, 70 degrees C and 60 min. The Fe-HP pretreated corncob shows a high sugar yield of 39.2 % (w/w) under the optimal enzymolysis conditions (50 degrees C, pH 4.8, 72 h). Ethanol yield of 35.2 % (w/w) was obtained under the optimal fermentation conditions (30 degrees C, pH 5.5, 72 h). Especially, the directional transformation of corncob to bio-jet fuels was achieved by integrating biomass fermentation and catalytic synthesis. High ethanol conversion of 95.9C-mol % and good jet fuel selectivity of 70.9C-mol % were obtained by using the bi-functional catalyst (HSAPO-34/NiH beta) under the optimal synthesis conditions (200 degrees C, 5 MPa, 3 h). Based on the biomass characterization and reactive oxygen specie's analysis, the possible role and mechanism of the iron-ion catalyzed hydrogen peroxide pretreatment was addressed. The iron ion catalyst can accelerate the decomposition of hydrogen peroxide to form hydroxyl radicals, and thus promoting biomass depolymerization and lignin removal from lignocellulose. The pretreatment increased sugar yield and concentration during enzymatic hydrolysis, which indirectly enhanced ethanol fermentation and biojet fuel production.