Biobutanol Production From Jerusalem Artichoke Stalk And Product Separation

With the gradual exhaustion of the fossil fuels like coal,petroleum and natural gas in the earth,more attentions have been paid on biofuels production derived from renewable biomass.Biobutanol as a second generation of new biofuels and important chemical reagents.But these can be related to food raw materials to produce butanol is not sustainable for solving the world's energy needs through the use of corn,sugar cane,etc.acetone-butanol?ABE?fermentation.At present the world has turned its research direction to lignocellulosic biomass for mass production of bio-butanol.The fermentation of lignocellulose was mainly divided into four parts: pretreatment,cellulase hydrolysis,acetone butanol?ABE?fermentation and separation.In order to optimize the pretreatment,enzymatic hydrolysis and ABE fermentation conditions,the utilization of biomass substrate and the yield of butanol were improved.The related research contents were as follows:The effects of different concentrations of NaOH-H₂O₂ on the pretreatment of Jerusalem artichoke were investigated.The content of cellulose,hemicellulose and lignin were 64%,11.7% and 5.3%,respectively,and the removal rate of lignin reached 84.1% after 2%NaOH-6% H₂O₂ pretreatment.When the hydrolysis of Jerusalem artichoke stalks 60 h,the hydrolysis rate reached the highest value.The concentration of reducing sugar after hydrolysis was 59.9 g/L.After 84 hours of fermentation,the final strengths of acetone,ethanol,butanol were 6.0 g /L,0.2 g/L,11.0 g/L,which was significantly higher than that of other pretreatment methods.The 2%Na OH-6%H₂O₂ was the best pretreatmen method.The effects of different pretreatment time of 2% NaOH-6% H₂O₂ on the hydrolysis of regenerated sugar in cellulase?Youtell-1500?were investigated.When the treatment time was 60 min,the strength of reducing sugars was 66.7 g/L?13.8 g/L,glucose sugar was 52.9 g/L?.After the pretreatment process,washing is required to remove the phenolic inhibitors during the pretreatment and the excess NaOH.The results showed that water washing to neutral was not necessary,and washed with water to neutral,washed three times with hydrochloric acid neutralized?3W?/ HN,and there was no significant difference in enzymatic hydrolysis and ABE fermentation.In addition?3W?/ HN achieved the highest butanol and ABE yields of 35.5 mg/g-JAS and 54.2 mg/g-JAS,while reducing water consumption by 64%.The effects of different strength of citric acid-sodium citrate buffer and initial pH of Jerusalem artichoke stalk hydrolyzate on ABE fermentation were investigated.The results showed that the final strength of ABE was 5.7 g/L,11.8 g/L and 0.2 g/L,respectively,when the buffer strength reached 0.06 mol/L and the initial pH of the extract of Jerusalem artichoke stalk was 6.2.Under the optimal conditions,the yields of butanol and total ABE were 0.25 g/g and 0.38g/g,respectively,which were similar to those of the control group?glucose as substrate?.In the in situ separation,the average separation factor for vapor stripping–vapor permeation of acetone,butanol and ethanol was 33.6,58.6,29.8,respectively.In the batch separation,the concentration of butanol in the fermentation broth was reduced to 1.0 g/L for 46 h after continuous vaporization.The experimental results show that vapor stripping–vapor permeation is better than pervaporation in the separation of butanol.