Investigation on Acetone-Butonal Clear Liquid Fermentation and Recycling Utilization of Fermentation Waste Liquid
|School||Hebei University of Science and Technology|
|Keywords||Radical ion Acetone - butanol fermentation Supernatant Corn starch IMMERSION Waste liquid|
Supernatant fermentation by the integrated processing of the fermentation raw materials in order to achieve the purpose of deslagging in advance, will be cleared after the deslagging sugar for fermentation, or directly by fermentation, full use of the raw material so that fermentation broth clarification. Adoption the clear liquid fermentation has many advantages, such as pollution less than with waste fermented; easy fermentation application of new technologies; improving device operating conditions; fermentation broth can be recycled, so as to achieve energy conservation, while fermented a small amount of residual liquid waste fermentable sugars and nutrients can be recycled. Supernatant fermentation has been applied to the industrial production of ethanol, but the production has not been reported in the acetone, butanol. The test Clostridium acetobutylicum 8008,8012 (CICC) bacteria, the fermentation of acetone, butanol supernatant. The thesis research content and results are as follows: 1 supernatant) acetone-butanol fermentation carried out a preliminary study. The first semi-synthetic medium with glucose as the carbon source Bingding clear liquid fermentation, solvent the highest yield of only 8.43 g / L, and there is a lot of residual sugar is not being used, the test results are not ideal. Then fermented brown sugar solution, sugar solution, respectively, the results showed that the brown sugar, compared with the utilization of sugar, the solvent yield to 14.50 g / L because brown sugar contains more nutrients, more suitable for the growth of microorganisms utilize. But there is still a large gap between the solvent production than corn flour fermented. The final corn flour soaking liquid to add glucose as a carbon source for the fermentation, solvent yield up to 20.31g / L, fermentation good results. 2) corn starch as a carbon source for the fermentation of Bingding supernatant. Test found a 50mL volumetric flask fermentation, respectively, in the pumping under vacuum and vacuum conditions, yield solvent less vacuuming operation and therefore can be omitted, to simplify the test process. The results show that the fermentation of corn starch corn flour sock liquid ADD good solvent production could reach 21.63g / L, and the optimal concentration of corn flour soaked 200g / L, corn starch moromi concentration of 7%, the alpha-amylase dosage 0.1%, the fermentation period of 72h, the the gelatinization time is 45min. 3) clear liquid fermentation is complete, the the fermentation liquid waste recycling research. The fermentation waste and corn flour leaching solution was mixed at different volume than probucol fermentation and found that, with the fermentation of the waste content increases, the solvent gradually decreased production. When using the fermentation liquid waste fermentation, solvent production by not adding fermented waste liquid 21.63 g / L to 0.96g / L, significantly inhibited. The same proportion of to maintain fermentation liquid waste with corn steep liquor, adjust the initial pH of 6.0, and solvent production is still low, pending further study. 4) The trial of corn starch as a carbon source, radical ion acetone-butanol supernatant fermentation. The results show that: the apparent inhibition of SO32-, and with the increase of the concentration, inhibition enhanced. SO42-, Cl-, CO32-, Ac-, PO43-corresponding sodium salt, an ammonium salt concentration in the fermentation within the range of 0.2 ~ 1.0g / L (w / v), wherein the solvent is the highest yield reaches 22.09g / L. SO42-, Cl-corresponding salt concentration increased to 2.0g / L, solvent production has declined. At different concentrations, respectively, several sodium salts, ammonium salts, mixed is added to the medium, and study the influence on the fermentation. The results found that does not add sulfite fermentation, to add sulfites fermentation abnormal, the yield is very low solvent only 1.806g / L, the same description of SO32-on acetone - butanol fermentation strong inhibition.