The Research On Purified Furfural Wastewater Diluting Molasses For Alcohol Fermentation

In our country, the Changling sugar beet plants was the first to use the process of making furfural from bagasse, which had a unique advantage in Guangxi province. It’s a new research subject for recycling the bagasse furfural wastewater. The furfural wastewater was produced from the process of making furfural, which had strong acidity and high concentration of COD and BOD. The main organic pollutants in the furfural wastewater was acetic acid, If the waste liquid was discharged directly, that would bring serious influence to environment and waste acetic acid resources. Therefore, looking for effective methods of waste liquid treatment and recycling waste could bring environmental, social and economic benefits, which was of great significance. The main research contents and conclusions were as follows.In this article, the process of active dry yeast used in molasses alcohol fermentation was optimized by single factor test and orthogonal test. Due to the problem of high acetic acid content in the furfural waste liquid, the effects of the acetic acid on molasses alcohol fermentation was researched, and immobilized yeast on molasses alcohol fermentation was also researched. The optimal technological conditions were:the fermentation temperature was30℃, inoculation quantity was1%, brix was30°Bx, pH was4.5, in this condition, the alcohol concentration reached9.8%. When acetic acid content exceeded0.45mL/100g, molasses alcohol fermentation was restrained significantly. The Calcium alginate-polyvinyl alcohol immobilized yeast had characteristic of not easy adhesion and high mechanical strength.Different flocculants and ion exchange resins were used in furfural wastewater treatment, and the treated furfural wastewater was substituted for some dilution water of molasses for alcohol fermentation. The results showed that process of the D280anion exchange resin treating furfural wastewater had a good effect, when resin treated wastewater statically, the resin content was200g/L, the adding amount of substituted furfural wastewater was40%, and alcohol production was7.5%, it reached expected result.Furfural wastewater was treated statically by different anion exchange resins in this experiment, the removal rate of acetic acid in furfural wastewater was detected, it was ensured that D280anion exchange resin treating furfural wastewater, and researched D280anion exchange resin treating wastewater statically and dynamically, the optimal process of resin treating wastewater statically was as follows:the temperature was25～35℃, the treating time was10min; the optimal process of resin treating wastewater dynamically was as follows:the flow rate of dynamic adsorption was5mL/min, the loading quantity was30g, the flow rate of eluent was4.5mL/min, the concentration of eluent was1mol/L, the temperature of eluent was40℃, in this condition, the treated furfural wastewater was substituted for100%dilution water of molasses in alcohol fermentation, NaAc crude product was recycled by evaporation crystallization, the infrared spectral analysis and purity testing was used in the crude product, NaAc had purity of60～70%.The innovation of this study was that:effective method of furfural wastewater treatment were ensured in experiment, the treated furfural wastewater was substituted for some dilution water of molasses for alcohol fermentation, and NaAc crude product was recycled in the process, which not only solved the problem of environmental pollution brought by furfural wastewater, but also saved the water consumption in dilution water of molasses and recycled some by-products, that contributed to circular economy and sustainable development of sugarcane.