Study On The Acid Hydrolysis Technology Of Lignocellulose Material And The Fuel Ethanol Fermentation Of Hydrolysate From Lignocellulose Material

The purpose of this research is to regard wooden cellulose material as raw materials of ethanol fermentation, The main research included concentrated sulfuric acid hydrolysis, dilute sulfuric acid hydrolysis, two stages acid hydrolysis, detoxification of hydrolysate, domestication of endurance of yeast and co-immobilized multi-microorganisms fermentation.Hydrolysis terms were optimized by single factor experiment, concentrated sulfuric acid hydrolysis and dilute sulfuric hydrolysis optimized hydrolysis craft, and better process conditions were gained, which were75%density (W/W) of concentrated sulphuric acid,1:2ratio of material and liquid, hydrolysis time1.0h in the concentrated acid pretreatment, density4%of sulphuric acid, hydrolysis time1.0h, atmospheric pressure in the dilute sulphuric acid hydrolysis.Detoxification methods of hydrolyzates have been investigated and the detoxification craft of hydrolysate was confirmed. The detoxification process was the hydrolyzate to boil for10-20minutes, later adjusted pH value to8-11gradually with Ca (OH)2neutralization, filtered, adjusted pH value to4-6with sulphuric acid, deposition30-50min on70-80℃,0.05%-4%density of sodium sulfite was mixed into and heated30-50min on90℃. filtered again and then concentrated to the proper density, and decoloured by the active charcoal of density0.3%-1%finally.Domestication of endurance of yeast to hydrolyzates of lignocellulose, compared with unadapt yeast, the research results showed that domestication yeast have better fermentation efficiency. the optimal fermentation conditions as follows:initial sugar concentration,60-100g/L, initial pH,5.6-5.7, fermentation time,48-60h, fermentation temperature,30-33℃.Immobilized cell technology was utilized to improve fermentation efficiency. conditon of craft which immobilized S.cerevisiae ferment hydrolysates of corn stalk was studied. it was found that fermentation term of immobilied S. cerevisiae shorted than dissociated S. cerevisiae. the optimal fermentation condition as follows:fermentation term,12-22h, initial sugar concentration,80-120g/L, initial pH,6.0, fermentation temperature,30-33℃.In order to utilize xylose fermentation sufficiently of the corn stalk hydrolysate, Fermentation conditions by co-immobilized multi-microorganisms was studied. The results find that the co-immobilized multi-microorganisms can cofermentation of hexose and xylose in the corn stalk hydrolysate. And the fermentation result was better than suspended multi-microorganisms, immobilized p.tannophilus and immobilized S.cerevisiae. The results indicated that the ethanol yield coefficient could reach a maximum of0.4g/g, ethanol concentration,21.34g/L. and the optimal fermentation conditions were determined respectively through single diathesis test as follows:initial pH:6.0, C/N=20:1-25:1, the ratio of multi-microorganisms is2:1-3:1, fermentation temperature:30-33℃...