SO₃ Micro-thermal Explosion Pretreatment Of Tobacco Stem And Fermentation Production Of Cephalosporin C

In this study,the SO₃ micro-thermal explosion technique was used to pretreat the waste tobacco stem.This holocellulose（the product）and its saccharification solution was used as carbon source to fermentation cephalosporin C（CPC）.At the same time,the pretreatment of tobacco stem produced lye content a mass of lignin（commonly known as lignin black liquor or black liquor）was studied by flocculation technology.Through this study,we hope to broaden the "value-added" utilization of abandoned tobacco stem,and make energy saving and environmental protection in the application process.The main results of this study are as follows:1.The removal of lignin from tobacco stem were studied by SO₃ micro-thermal explosion combined with dilute alkali solution.Taking the removal rate of lignin and the yield of cellulose as an index,the pretreatment process was studied and the optimum process route was follows: 2% of SO₃,60 ℃ microburst 2h,washed with water at 50 ℃ for 1h,then washed with 2% of K₂CO₃ dilute alkali solution for 3h.Under the above conditions,the removal rate of lignin reached 82.20%,and the content of holocellulose was increased to about 90%.The structure of the tobacco stem was studied by means of apparent morphology,scanning electron microscopy（SEM）,infrared spectroscopy（FT-IR）,crystallinity（XRD）and elemental analysis（XPS）.It was further verified that SO₃ The process mechanism of the pretreatment.2.Cephalosporin C was obtained by fermentation of Cephalosporium acremonium CPCC 400039 using the hollocellulose and its saccharification solution obtained by pretreatment of tobacco stem as carbon substitute.Taking CPC as the index,the research shows that: The yield of cephalosporin C was 382.12 U / mL when holocellulose 40 g / L,the cellulase 0.4%,the ammonium sulfate 10 g / L,the corn syrup 60 g / L and the initial pH was 6.0,Which is 84.04% of the standard starch medium production.3.In the study of lignin in black liquor by membrane-bound flocculation,in the separation of black liquor in the lignin at the same time to achieve the partial recovery of alkali solution.The flocculation product was characterized by FT-IR and XPS,indicating that the product was lignin.Taking lignin recovery as an index,the results showed that the ultrafiltration was carried out with 5000 Da ceramic membrane,and 0.4 concentrated lignin black liquor with 1.5% quaternary ammonium salt 4 as flocculant,pH 11.5 room temperature magnetic stirring for 1 h in the study of lignin in black liquor by membrane-bound flocculation.The lignin recovery was 44.43 %,COD value can be reduced by 53.34%,lye can be recycling applied at least 10 times and save 15% of potassium carbonate,30% of the water.