The Key Technology Study Of Fuel Ethanol And Protein Feed From The Sweet Sorghum Stems

Cellulosic ethanol is one of the important measures to alleviate theworld's energy crisis.Sweet sor ghum because of its easy to grow,adaptable,high light efficiency,utilization value to many other advantages,has become one of the most popular cellulosic feedstock for ethanol production.In this study,sweet sorghum as raw material for fuel ethanol research.Different pretreatment,fermentation under way to find the optimal combination of different pretreatment conditions,simplified fuel ethanol production technology,promote industrialization use of fuel ethanol and co-generation protein feed production.Firsterly,sweet sorghum for raw materials,through the loss rate and results under different concentration of the acid or alkali pretreatment conditions show that ethanol yield,p H optimum pretreatment conditions is: 1% KOH,75% of the material moisture rate,115?,40 min pretreatment,material loss under these conditions is 8.94%,ethanol yield is 6.362 g/100 g DM.Secondly,the effects of different concentrations of acid or alkali pretreatment,the pretreatment and washing down the differences between the materials are not washed,and the different conditions of liquid saccharification saccharification and fermentation step of the pros and cons,the results showed that:After finishing the pretreatment,the material loss rate is washed with water and ethanol group rates very significantly?P<0.01?higher than the group without washing;dilute H₂SO₄ and Na OH pretreatment of sweet sorghum stalks after washing saccharification,fermentation ethanol,ethanol yield There is no significant difference?P=0.63?.Different concentrations of acid or alkali pretreatment optimum pretreatment conditions is: 1.0% H₂SO₄,washed with water after the pretreatment,saccharification 48 h,after the end of saccharification glucose concentration is 19.142 g/L,xylose concentration is 4.755 g/L,Arab the sugar concentration was 2.045 g/L,is 33.91% of the final material loss,the ethanol yield is 5.869 g/100 g DM,residual xylose fermentation broth at a concentration of 1.088 g/L,arabinose concentration of 0.586 g/L.Thirdly,by 28 steam explosion pretreatment conditions and solid state studies simultaneous saccharification and fermentation conditions to obtain the following conclusions:2.3 MPa-180 s for the best steam explosion pretreatment conditions,under the conditions of three vegetable material?cellulose,hemicellulose,lignin,the same below?the absolute amount was 23.03% cellulose,hemicellulose 3.7% lignin 20.91%.This condition after steam explosion pretreatment material washing,extraction,solid-state simultaneous saccharification and fermentation optimum fermentation conditions are: fermentation time 120 h,70% moisture content,fermentation temperature 34?,under this condition,the ethanol yield was 5.873 g/100 g DM.Fourthly,by scanning electron microscopy?SEM?analysis,Fourier transform infrared spectroscopy?FTIR?analysis,X-diffraction?XRD?analysis,further elaboration and comparison of physical surface morphology and internal structure of sweet sorghum stalk under different pretreatment conditions changes.The results showed:Pretreatment conditions are different on the surface of sweet sorghum stalks have a huge role in the destruction,the extent of damage are 2.3 MPa-180 s steam explosion pretreatment> 1% H₂SO₄ pretreatment> 1.5% Na OH pretreatment.Different pretreatment conditions can greatly undermine sweet sorghum stalks three prime structures.2.3 MPa-180 s steam explosion pretreatment extent of the damage to the three elements of the most serious,the raw material of cellulose,hemicellulose,lignin has a higher destructive;1.5% Na OH pretreatment major damage to the structure of three vegetable lignin and cellulose and hemicellulose portions;1% H₂SO₄ pretreatment major damage to the structure of the three vegetable hemicellulose,cellulose and lignin limited damage to the.Different pretreatment huge impact on sweet sorghum stalk crystalline region and the amorphous region.Pretreatment cause removal of lignin and hemicellulose and other amorphous material,resulting in increase in the pretreated material relative crystallinity index.Fifthly,by a variety of microorganisms to optimize the combination of different mass fraction of urea sweet sorghum stalks are the raw material of solid-state fermentation production of protein feed study the optimum conditions are as follows:Adding Aspergillus niger,Trichoderma reesei,Candida utilis and Lactobacillus casei 4 composite inoculum strains on the raw material sweet sorghum stalks crushed,and then the addition of 1% urea,8 d after fermentation to make sweet sorghum stalks to bottom the feed are reduced from cellulose from 33.00% to 24.09%,hemicellulose decreased from 20.99% to 17.69%.crude protein content increased from 2.27% to 7.14%,true protein increased from 2.01% to 6.41%.