Use of hydrodynamic methods to enhance membrane filtration efficiency of sugar produced by rice straw hydrolysis
| Autor: | Hung-Yuan Tsai, 蔡鴻源 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 The separations of sugars from hydrolysis suspension using hollow fiber and flat plate membranes are studied. The effects of operating conditions and hydrodynamic methods on the sugar separation performance are discussed. The hollow fibers used in the experiments are made of polysulfone, and their mean pore size is 10 kD. In the filtration of pure glucose, the main resistance source is the membrane because of trivial membrane fouling, and the sugar transmission decreases slightly under high pressures. When enzyme exists in the suspension, the filtration rate decreases about 85 - 90% compared to those in the filtration of pure glucose. The major resistances are due to the enzyme blocking in the membrane pores and the cake formation on the membrane surface. Increasing the transmembrane pressure results in higher glucose yield. However, this effect becomes trivial when the pressure exceeds 80 kPa. An increase in cross-flow velocity under fixed transmembrane pressure leads to higher filtration rate. The filtration rate increases three times when cross-flow velocity increases from 0.3 to 1.5 m/s. Some empirical equations are established to correlate the filtration resistances with operating conditions. The filtration rate can be estimated accurately by substituting the calculated resistances into modified Darcys’ law. In addition, several hydrodynamic methods are tested to increase the filtration rate. A pulse feeding way may increase the filtration rate by 24.7%, while the way of step-increasing pressure can increase the filtration rate as high as 34.6%. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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