Experimental Study On Fuel Ethanol Production By Corn Stalk

With the increasing consumption of traditional resources such as coal and petroleum, the development and preparation of some renewable resources has become the hope for people to continue to live on the earth. It has also got the attention and attention of people all over the world. Fermentation production of biological raw materials such as straw Fuel ethanol has become a hot research field of renewable energy. China’s population, less arable land, which makes the production of fuel ethanol can only go "non-food" line. China’s corn planting mask ranks second in the world, in the harvest of corn at the same time will be harvested hundreds of millions of tons of corn stalks, but only less than 10%of the effective use, which not only cause serious waste of resources, and straw directly disposed of nowhere to throw away But also pollute the environment, so the corn stalks turning waste into treasure, as its fermentation of ethanol production of raw materials is to change the current situation of a good way. In this paper, corn straw as; the main raw material for fermentation, the production of fuel ethanol, the main contents are as follows:1. respectively, with humic soil, rotting straw, rot wood and other samples as the source of bacteria, through the cellulose selected agar media selection of cellulose degradation bacteria, after screening and re-screening,#2,#3,#5,#9 and#10 strains were more active than those of Aspergillus niger and Trichoderma viride, and the degrading effect reached the peak on the 6th day. The results showed that the cellulase system of the screened strain was extracellularly secreted, which was associated with the cellulase produced by fungi. Consistently, theenzymes produced by these strains were assayed for enzymatic activity, and the cellulase produced by the screened strains were all acid enzymes. In contrast to the CMCA and FPA determinations of these strains, the predominance of Aspergillus niger in CMCA activity was relatively high, up to 3593 U, and the strains#6,#9 and#10 were slightly smaller,#2,#3, #5 further reduced, but the vigor is still stronger than Trichoderma viride. The FPA activities of#5,#6,#9, and#10 were higher than FPA, and FPA was stronger than that of Aspergillus, the highest FPA activity was up to 760U;2.150 strains of bacteria were isolated and purified from 30 samples of Ligninolytic enzyme, and 9 kinds of fungi strains with the ability of degrading lignin were obtained through the color reaction of GU-PDA. Two strains of strains 15-8 and 16-2 with higher ligninase activity were obtained by the re-screening of the ligninase activity of these 9 fungi;3. Pretreatment of com stover with dilute sulfuric acid at a temperature of 120 ℃, the crystal structure of lignin after treatment, hemicellulose and cellulose broken in straw, partial hemicellulose hydrolysis, after treatment of crude fiber The content of raw material of removing lignin was increased from 35% to 46%. Compound strains by 45.82%; Crude fiber utilization ratio can be increased to 55.65%. Finally, the physical, chemical and biological methods after pretreatment, the structure of the raw material is loose, and crude fiber utilization rate rise to 54%.The effect is better than that of single strain composite strain pretreatment of lignocellulosic material, which should be the alternating or symbiotic relationship of single strain mixed form. The composite effect should be strengthened through the deepening of its relationship. Because of its ability to degrade lignin, Capacity, so the biological pretreatment time should not be too long;4. The optimal fermentation conditions of the mixed medium were: pH value, inoculation quantity, temperature, shaking speed and so on. The optimum fermentation conditions were as follows:inoculation 10%, pH 5.5, shaking speed 120 r/min, temperature 30 ℃. Under these conditions, the sugar alcohol conversion rate was 38.4%. The orthogonal experiments showed that the influence of the four main factors on the fermentation was:temperature> shaking speed> pH> inoculation amount.