水稻秸秆与PVC塑料共气化过程中钾、钠、氯的迁移行为

Transformation of K,Na and Cl elements in the co-gasification of rice straw and PVC

采用固定床反应器,结合X射线衍射（XRD）表征和热力学计算研究了水稻秸秆与PVC塑料共气化过程中钾钠氯的迁移和状态变化.结果表明,混合物中氯的释放率与反应温度和PVC塑料的量（氯含量）有关.当反应温度为800～900℃时,PVC的量对混合物中氯元素释放率的影响最为显著;气化温度达900℃时,含PVC 20％（氯含量为11.5％）的水稻秸秆混合物中,氯元素的释放率较纯水稻上升了16.5％.与此同时,氯含量的增加也促进了钾钠在气相中的释放.气化温度为850℃时,当混合物中PVC比例大于20％（氯含量大于11.5％）时,氯对钾钠的气相析出有一定抑制作用;钾钠以KCl和NaCl的形式滞留在固相中,其含量随着混合物中PVC量的升高而降低.

The co-gasification of rice straw with PVC was carded out in a fixed bed reactor; the transformation of K, Na and Cl elements was investigated through X-ray diffraction （XRD） and thermodynamic calculation. The results indicated that the release of chlorine is related to the operation temperature and PVC proportion in the co-gasification of rice straw and PVC. The content of PVC in the blend plays an important role in the release of Cl, especially at 800 -900 ℃ ; the amount of Cl released in gasification of the blend with 20% PVC （ 11.5% CI） is increased by 16.5%, compared with that of pure rice straw at 900 ℃. Meanwhile, the increase of CI content in the blend also prompts the release of K and Na. When the fraction of PVC is higher than 20% （ 〉 11.5% Cl）, the presence of Cl can restrain the release of K and Na at 850 ℃, which are retained in the ash as KCl and NaCl during the co-gasification of rice straw and PVC at 850 ℃ ; the content of which decreased with the increase of PVC countent in the blend.