Preparation , Performance and Characterization for Zeolite Adsorbent
| Autor: | Chi Hua Lee, 李琪華 |
|---|---|
| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 Volatile-organic-compounds (VOCs) containing waste gas are normally controlled by condenser, wet scrubber, activated-carbon absorber, regenerative thermal oxidizer(RTO), catalytic oxidizer (CAO), and zeolite rotor concentrator. Among them, zeolite rotor concentrator is the most popular one. However, because of the complexity in pollutant, the rotor is suffered by quick deactivation cased by destruction of Zeolite. The drawbacks motivate us to develop a high performance and regenerable adsorbent. The main function for VOCs adsorption is still Zeolite. However, by controlling pore diameter and hydrophobic properties of matrix (binder for adhering zeolite), an adsorbent can be tailored for a specific requirement. Moreover, for the utilization in waste gas of low concentration high flow rate, adsorbent of hollow cylinder in shape was prepared by a screwing-extruding forming machine of laboratory scale for performance test and the machine was further scale up to commercial scale for industry application. The adsorbent was characterized by TPO (temperature-programmed-oxidation), TPD(temperature-programmed desorption), XRD (x-ray diffraction), SEM (scan electron microscopy), and adsorption performance test. For different kind of zeolite or spent zeolite, namely, Y zeolite, ZSM-5, ROC, and FCC spent catalysts, have been tested. The adsorption capacity for these 4 zeolite is in the order: Y > ZSM-5>ROC and FCC. It may be caused by the pore mouth plugging during adsorbent preparation, the adsorption capacity of ZSM-5 is not as high as we expected, whereas the performance adsorbent made from Y was good enough for considering commercial run and the formulation for preparation was further tuning with the guide of the complemented characterization tools. In addition, the regenerability was test with cycled accelerated aging tests and the results indicated that after 6 cycles, no significant deactivation was observed. In viewing of these results, a large scale of adsorbent was prepared based on the formula developed in the lab. And the test results showed that the performance, including mechanical strength and adsorption capacity, of the sample prepared from commercial scale was even better. In the coming future, different adsorbent will be developing for handling VOCs of variety properties, and hopefully the performance of the adsorbent will also be tested in commercial run . |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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