| Cellulosic ethanol is production utilizing wood and crop waste as a raw material，Not only can solve the problem of the waste which is difficult to use, but also sloweddown the oil crisis, Providing a sustainable development path for society. Agriculturemaintain China’s economic survival,and corn planting has a large proportion.Incineration of corn straw cannot make the corn straw reasonable utilization, and itpollutes environment, what is more, it exacerbates global greenhouse effect. Cornstraw become raw material that have extensive source and high Sugar conversion rate,because it contains more than50%of hemicellulose and cellulose.As the object in this study, corn straw was pretreated through explosion and lowacid, reaching the purpose that the raw material structure was destructed, and it washydrolyzed, in order to obtain hydrolysate which xylose was rich in. By using themethod of single factor and orthogonal experiments, four factors on the influence ofhigh temperature water hydrolysis of wood materials were studied, and optimumprocess parameters of hydrolysis wood materials was: Explosion treatment parameters:tension3Mpa, time4min. Hydrolysis parameters: Solid content12%, dilute acidconcentration1.4%, reaction temperature125℃, reaction time80min. Under thereaction conditions, the xylose yield can reach20.3g/L. On the basis, hydrolysate wasconducted detoxification and highly concentrated, then fermented. By using themethod of single factor and orthogonal experiments, four factors on the influence ofpentose fermentation were studied, and optimum process parameters of pentosefermentation was: Concentration of xylose is60g/L, agitation speed is220r/min,temperature is30℃, initial pH value is4.5,Candida shehaatae inoculum is10%,3%fermentation broth had fermented after10h, fermentation time is56h. Under theseconditions, the ethanol yield reached22.1g/L. after low acid hydrolysis, raw residuehad a small amount of pentose content, which can be used to produce cellulase byliquid fermentation. By using the method of single factor and orthogonal experiments,four factors on the influence of liquid cellulase fermentation were studied, andoptimum process parameters of cellulase fermentation was: Trichodermareesei:Aspergillus niger was5:1, Aspergillus Niger spore suspension inoculation delayed aday,Temperature is32℃, Total inoculation amount7%, pH value is5.5, Time is7d,Feeding straw3%, bean cake powder1.5%every three days. Under the reactionconditions, FPA reached to3.4IU/mL. Hexose was fermented by asynchronous enzymatic hydrolysis and fermention of liquid enzyme and yeast. By using themethod of single factor and orthogonal experiments, four factors on the influence offermentation production of hexose were studied, and optimum process parameters ofcellulosic ethanol fermentation was: concentration of the cellulase is10times, solidcontent is7%, cellulase solution1%(v/v), The temperature is50℃, pH is5,saccharification process conduct1d. Then Temperature is38℃, inoculation amount10%, pH value is5.0, the time is4d. Under these conditions the ethanol yield reached18.0g/L. |
