| 内容提要: |
An EtOAc/H2O biphasic solvent-Ru/C coupling bio-refinery process was developed to selectively produce aromatics from cornstalk hydrolysis residue (CHR). In this process, CHR was depolymerized in ethyl acetate (EtOAc)/H2O biphasic solvent system over Ru/C catalyst, then produced aromatics and carbohydrates were instantly separated by EtOAc and H2O. Most lignin in CHR was converted to aromatics and non-volatile fractions, accompany with partial degradation of cellulose. Optimized results showed that more than 42.7% of aromatics can be obtained under 260℃ for 5h without external hydrogen pressure. Monophasic and biphasic parallel experiment results show that the strong lignin dissolved ability of biphasic dissolution/separation system is helpful for aromatics production and separation, which promoted the CHR depolymerization over Ru/C. Furthermore, CHR, products, depolymeirzation residue solid (DRS) and catalysts were carefully characterized by GC-MS, FT-IR, GPC, HPLC-MS, NMR, XRD, XPS, SEM and ICP-AES analysis. Results demonstrated that the biphasic solvent-Ru/C coupling process can significantly alleviate repolymerization reactions. Based on these analysis results, the catalytic process in biphasic EtOAc/H2O was discussed. This work demonstrates that such a green biphasic catalytic/separation coupling system highlights a promising route for efficiently biomass degrade and product separate at mild condition without external hydrogen pressure. |