Synthesis Of Furfuryl Alcohol From Bamboo Shoot Shell And Xylose By Chemical-biological Catalysis

Nowadays,with the shortage of supply and demand of natural resources such as fossil fuels and the increasingly serious environmental problems,the development and utilization of renewable resources hasve become the research work concerned by researchers.As one of the renewable resources of green and environmental protection,lignocellulose is mainly from wood and agricultural waste.It is not only rich in cellulose,cheap and easy to obtain,but also widely used in the synthesis of various high-value compounds.Furfural（FAL）is one of the important derivatives of lignocellulose,and it is a high value of industrial chemical product.It can be used in the synthesis of medicine,pesticide,resin,furfuran,tetrahydrofuran,etc.Furfuryl alcohol（FOL）derived from furfural can be used to synthesize rocket fuel,rubber and other organic chemical materials.The traditional method of FOL synthesis mainly includes two production routes:liquid-phase method and gas-phase method.It is necessary to produce FOL by gas-phase or liquid-phase,According to the different reaction systems,the previous synthesis methods of FOL can be divided into liquid-phase and gas-phase production routes.Whether the gas-phase or liquid-phase production of FOL requires high reaction conditions.The whole process is accompanied by high energy consumption,high pollution and other problems.Therefore,biological method has attracted people’s attention.Compared with chemical synthesis,the conditions of FOL synthesis by biocatalysis are more mild,and the selectivity and conversion efficiency are very high.And the whole process does not produce high pollution waste.In this study,the synthesis of FOL from bamboo shoot shell and xylose was conducted via tandem catalytic reaction with the prepared solid acid catalyst SO₄^2-/Sn O₂-CS and recombinant E.coli whole cell containing reductase.The results were obtained as follows:Firstly,SO₄^2-/Sn O₂-CS solid acid catalyst was prepared by using corn straw（CS）powderas carrier.The SO₄^2-/Sn O₂-CS and corn straw were characterized by BET,SEM,FT-IR.The results showed that the treated corn straw powder particles decreased,and the surface became loose and porous,the specific surface area increased to 27 m²/g,and the pore volume expanded to 0.12 cm³/g.These changes promoted the reaction by increasing the contact area between catalyst and substrate,and effectively catalyzed the production of FAL from bamboo shoot shell and xylose.Using 3 g bamboo shoot shell as feedstock,the yield of FAL was 39.0%by SO₄^2-/Sn O₂-CS（3.6 wt%）in a high temperature reactor at 170℃,which proved that SO₄^2-/Sn O₂-CS prepared from corn straw could effectively catalyze the synthesis of FAL from bamboo shoot shell in the aqueous system.Moreover,the suitable performance conditions for catalyzing xylose by SO₄^2-/Sn O₂-CS was optimized in the presence of formic acid.The yield of FAL from 100m M xylose reached the highest value at 48.0%within 20 min in the presence of formic acid（200 m M）and SO₄^2-/Sn O₂-CS（0.3 wt%）in deep eutectic solvent（DES）Ch Cl:EG-water（1:1,wt:wt）media.Secondly,recombinant strain E.coli CF cells containing reductase were used to synthesize FOL from bamboo shoot shell-and xylose-derived FAL in the aqueous system.To achieve the optimal reaction system and obtain higher reaction efficiency,the factors of the biocatalytic synthesis of FOL in aqueous phase were investigated.The optimal reduction conditions were as follows:cell dosage 0.050g/ml,reaction temperature 35℃,reaction p H 7.5,cosubstrate dosage3 mol sodium formate/mol FAL,NADP⁺1.5μM NADP⁺/m M FAL,metal ion additive Sn⁴⁺0.50 m M.Under the optimal conditions,the whole cell of E.coli CF could tolerate 150 m M FAL,and the 100 m M FAL from bamboo shoot shell and xylose could be completely transformed into FOL.Finally,recombinant strain E.coli CF cells were employed to catalyze FAL into FOL in Ch Cl:EG-water system.The optimum conditions for whole cell catalysis of the two-phase system were determined.The optimal reduction system was determined as follows:cell dosage 0.75 g/m L,catalytic temperature 35℃,and catalytic p H7.5,cosubstrate loading 2.5 mol sodium formate/mol FAL,NADP⁺dose 1μM NADP⁺/m M FAL,metal ion additive Sn⁴⁺0.1 m M.Thus,the tandem catalytic transformation of bamboo shoot shell and xylose by SO₄^2-/Sn O₂-CS solid acid and E.coli CF whole cell was developed in Ch Cl:EG-water system.In conclusion,FOL was attempted to synthesize via chemical-biological approach in tandem catalytic reaction with SO₄^2-/Sn O₂-CS catalyst and reductase whole cell biocatalyst using bamboo shoots shell and xylose as feedstocks in aqueous system and Ch Cl:EG-water system.These routes were verified.Thus,this case provided a new idea for the synthesis of key intermediate FOL.