| Abstract: | 利用Clostridium acetobutylicum 發酵產生丙酮(Acetone)、丁醇(Butanol)、乙醇(Ethanol) (ABE)，此發酵製程的歷史悠久，但生產技術和轉化率遠比不上現代石化工業產量，使得生物發酵製程逐漸沒落，近年來能源危機問題再度的讓生物發酵製程受到重視。生物發酵製程生產丁醇主要的瓶頸在於丁醇毒性的抑制導致生產效率下降，最終丁醇濃度偏低；進而失去商業競爭性。因此本實驗結合滲透蒸發程序與ABE發酵製程，同步移除發酵槽內丁醇與其他代謝產物，使產物丁醇和發酵液分離、進而純化，以得到高濃度的丁醇，並提升整體的生產速率。本研究中滲透蒸發系統所採用的薄膜為聚醚-聚醯胺嵌段共聚物PEBA 2533 (Polyether block amide) + 奈米碳管CNTs(Carbon nanotubes)。實驗探討不同比例的CNTs添加量(PEBA、PEBA+5%CNT、PEBA+10%CNT)製作薄膜並去找尋最佳選擇比，做為連續式發酵中滲透蒸發的薄膜材料。在模擬溶液中丁醇移除通量分別為9.975、16.095、15.875 (g/m2/h)，丁醇之選擇比參數 (selectivity)方面為17.4、19.4、18，添加CNTs使得丁醇的通量和選擇比都會明顯上升，由於薄膜強度也會隨著CNTs的增加而提高，在連續式發酵中應用PEBA和PEBA+10%CNT薄膜，丁醇生產速率(productivity)分別為0.270、0.339 (g/L/h)，單位葡萄糖之丁醇轉化率(yield)為0.169、0.203 (g/g)。實驗結果證實CNT的添加，可以維持發酵中丁醇濃度低於毒性抑制的範圍中，進而提升整體的丁醇發酵產率。
Clostridium acetobutylicum produce acetone and butanol, ethanol, (ABE) by fermentation. This fermentation process has a long history, but the production technology and the conversion rate are far smaller than the modern petrochemical industry production. The fermentation process is gradually disappearing, and the energy crisis in recent years the problems of fermentation process to be taken seriously. The main bottleneck of the fermentation process is butanol toxicity of inhibition lead to the decline in production efficiency. The final butanol concentration is low, and thus loss of business competition.In this study, it combined with pervaporation and ABE fermentation process. It can remove the fermentation tank butanol and other metabolites in the same time, so it could separate butanol and fermentation liquid then purify to high concentrations. Then enhance the overall production rate. In this experiment, pervaporation system using membrane for the polyether block amide with Carbon nanotubes.Experimental Investigation of CNTs added in different proportions (PEBA, PEBA +5% CNT, PEBA +10% CNT) Production of the membrane and to find the best choice, as the continuous fermentation pervaporation membrane materials. Butanol to remove flux in the model solution were 9.975, 16.095, 15.875 (g/m2/h) and butanol selection of parameters (selectivity) were 17.4, 19.4, 18. Add CNTs makes butanol flux and choices will be obvious increase. The membrane strength and CNTs addition are positive correlation. the application of PEBA and PEBA +10% of CNT membrane in a continuous fermentation, butanol productivity, respectively, for the 0.270, 0.339 (g/L/h). Yield for the 0.169, 0.203 (g/g). The experimental results confirmed that the addition of the CNT could maintain the fermentation of butanol concentration lower than the range of toxicity suppression. Therefore enhance the overall yield of butanol fermentation. |
