Construction Of Calcium Chloride/Sodium Dodecyl Sulfate/Solid Acid System And Its Catalytic Properties For Cellulose Hydrolysis

Hydrolyzing cellulose into reducing sugar is a way to make full use of carbon resources to alleviate energy shortages and environmental pollution.It is one of the important topics in cellulose research today for how to convert it cheaply,efficiently and environmental-friendly.In this paper,the two cellulose pretreated by ball milling and phosphoric acid are used as the hydrolysis experiment object.And the catalytic system with calcium chloride(CaCl2),sodium dodecyl sulfate(SDS)and sulfonated carbon-based solid acid,including sulfonated carbon-based solid acid-L(SCSA-L)and sulfonated carbon-based solid acid-S(SCSA-S),was constructed.Its catalytic properties in cellulose hydrolysis were investigated.First,the ball milling and phosphoric acid pretreated cellulose were compared with the original microcrystalline cellulose in the hydrolysis experiment.In the absence of a catalyst,the cellulose was hydrolyzed at 150? for 12 h in a 25 mL autoclave and the results showed that the yield of reduced sugar(TRS)of the two pretreated cellulose were both improved.Among them,the cellulose treated with phosphoric acid has a TRS yield of 20.2%,which is 11 times that of untreated microcrystalline cellulose.The characterization results obtained by XRD,TEM and FT-IR showed that the morphology and crystallinity of the two pretreated cellulose were changed to some extent.On this basis,metal chloride(XCln:n=1,X=Na,K;n=2,X=Mg,Ca,Sr,Ba)and surfactant(sodium dodecyl sulfate,sodium dodecyl sulfonate)were introduced into the hydrolysis reaction and their properties in cellulose hydrolysis were studied.The results showed that the TRS yield can be increased to 63.7%when the CaCl2/SDS system hydrolysis ball milling cellulose.Secondly,carbon sphere-L were prepared by using glucose as a carbon source and selecting certain carbonization conditions,and then a series of sulfonated carbon-based solid acid-L(SCSA-L)was obtained by performing sulfonation under appropriate conditions.The carbon source,dosage of FeCl3 and sulfonation time were optimized.SCSA-L obtained by sulfonation for 11 h at a certain sulfonation temperature(110?)showed a good catalytic potential The CaCl2/SDS/SCSA-L system constructed by the method has a TRS yield of 68.6%and 71.2%,respectively.when catalyzing hydrolysis of the ball milling and the phosphoric acid pretreated cellulose.Finally,another carbon sphere-S was obtained by changing the carbonization conditions of glucose,and different sulfonation temperature were used to prepare the sulfonated carbon-based solid acid-S(SCSA-S).SCSA-S prepared by sulfonation at 110? within a constant sulfonation time(10h)has a good catalytic potential.The CaCl2/SDS/SCSA-S system constructed by the method has a TRS yield of 70.4%and 73.5%,respectively,when catalyzing hydrolysis of the ball milling and the phosphoric acid pretreated cellulose.