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    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/52319

    Title: 以掃流透析過濾及透析濃縮葡萄糖/木糖水溶液
    Other Titles: Use of cross-flow diafiltration & dialysis for glucose-xylose concentration
    Authors: 陳冠忠;Chen, Kuan-chung
    Contributors: 淡江大學化學工程與材料工程學系碩士班
    黃國楨;Hwang, Kuo-jen
    Keywords: 透析過濾;透析;葡萄糖;分離效率;Diafiltration;Dialysis;Glucose;Separation efficiency
    Date: 2010
    Issue Date: 2010-09-23 17:32:44 (UTC+8)
    Abstract: 本研究是以平板式掃流透析過濾與透析來分離稻稈酵素水解後溶液中的糖類。以孔徑0.025um之醋酸纖維膜與5kD、10kD再生纖維膜進行透析與過濾實驗,探討過濾方式、膜的種類與膜孔的大小對過濾速度、過濾阻力、糖的阻擋率與產率的影響。首先以孔徑0.025um與0.1um之醋酸纖維膜進行單成份葡萄糖的過濾,探討掃流速度與透膜壓差對過濾性能的影響;實驗結果顯示:影響濾速的主要阻力來源為薄膜的阻力,而對糖的阻擋率皆小於百分之十。經由濃度極化膜式的解析,可以獲得模式中的參數,並得以預估濾速。若以稻稈酵素水解過後的水解液來進行過濾,實驗結果顯示:以5kD再生纖維膜進行透析過濾時,濾速過低,所以濾液中糖的產率不高;若改用10kD再生纖維膜進行透析過濾,則操作3小時後產率可提高2.5%。分析不同的掃流速度與透膜壓差下的各種過濾阻力可知:薄膜的阻力仍是主要的阻力來源,且糖的產率低於3%。若改用0.025um之醋酸纖維膜來進行過濾,結果發現濾速與糖的產率並沒有提高,這是因為薄膜表面有酵素的結垢層產生所致。經由阻力分析可知:主要的過濾阻力為結垢層造成的阻力,佔了總阻力的72%,改變掃流速度從0.1到0.5m/s時阻力從66%到72%,改變過濾壓差阻力從44%到72%,主要的影響為過濾壓差的影響。若以0.025um之醋酸纖維膜與10kD再生纖維膜進行透析實驗,結果發現醋酸纖維膜表面不會形成結垢層,而且掃流速度越快,收集到糖的總量也就越多,但在60分鐘內即可達平衡。比較相同掃流速度下透析過濾與透析的產率,在操作3小時(時間)內,使用再生纖維膜進行透析過濾可以獲得較高的糖產率,但由於薄膜的阻力,所以糖的產率還是低於3%。
    In this study, sugars produced by enzyme hydrolysis of rice straw are separated by cross-flow diafiltration and dialysis. Three kinds of membranes, made of mixed cellulose ester with a mean pore size of 0.025 um and made of regenerated cellulose with MWCO of 5 kD and 10 kD, are used in experiments. The effects of filtration mode, membrane type and pore size, cross-flow velocity and filtration pressure on the filtration rate, sugar rejection and yield are discussed. In the first part, 0.025 um and 0.1 um membrane made of mixed cellulose ester are used to filter pure glucose suspension. Experimental results show that major filtration resistances are caused by the membrane, and the sugar rejections are less than 10% within the operating conditions of this study. Concentration polarization model, which parameters can be obtained using experimental data, is employed to estimate the filtration rate. In the second part, the suspension obtained from rice straw hydrolysis is used in diafiltration and dialysis after a pretreatment. The results show that the filtration rate in diafitration using 5 kD regenerated cellulose membrane is very low, the sugar yield in the filtrate is therefore low. When 10 kD regenerated cellulose membrane is used in diafitration, the sugar yield increases to 2.5% in 3 hours operation. The membrane resistances are the main resistance source under various cross-flow velocities and filtration pressure, and the yield of sugar is still lower than 3%. On the other hand, the results of filtration using 0.025 um mixed cellulose ester membrane indicate that no obvious improvements on the filtration rate and sugar yield can be found due to the formation of a fouled layer on the membrane surface. The resistance due to this fouled layer is as high as 72% of the total resistance. The filtration resistance increases from 66% to 72% as cross-flow velocity increases from 0.1 to 0.5 m/s. Filtration pressure plays more effects on the resistance, the resistance changes from 44% to 72% of the total resistance in the conditions of this study. In the dialysis experiments using 0.025 um mixed cellulose ester membrane, no fouled layer is formed on the membrane, and the collected sugar increases with increasing cross-flow velocity. The pseudo-steady state will be reached in 60 min. Comparing the yields obtained in diafitration and dialysis under the same cross-flow velocity, the diafitration using 10 kD regenerated cellulose membrane yields more sugars in 3 hours operations. However, the yield of sugar is lower than 3% due to the fouling resistance.
    Appears in Collections:[化學工程與材料工程學系暨研究所] 學位論文

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