HY、USHY和SSHY沸石的改性及催化性能

Modification and Catalytic Performance of HY、 USHY and SSHY Zeolite

用Ｋ２ＳＯ４ 溶液对ＨＹ、ＵＳＨＹ 和ＳＳＨＹ 沸石的酸性进行改性，通过调节Ｋ２ＳＯ４ 溶液的浓度、温度和交换次数，可控制沸石的酸强度和酸量。对于ＨＹ、ＳＳＨＹ 和ＵＳＨＹ 只需用０ ．００１ ｍｏｌ／Ｌ Ｋ２ＳＯ４ 溶液在４０ ℃交换１ 次，当反应温度为３００ ℃时，前两种样品可避免正庚烷发生裂解反应，而后者可发生裂解反应，显然前两种样品适合做为异构化催化剂。酸强度测定表明，裂解能力不仅和酸强度有关，而且和酸的类型等其它因素有关。用０ ．０１ ～０ ．１ ｍｏｌ／Ｌ Ｋ２ＳＯ４ 溶液在４０ ℃交换１ 次，可使ＨＹ、ＳＳＨＹ 和ＵＳＨＹ 的酸强度达到中强酸的程度。改性后的ＨＹ、ＵＳＨＹ 和ＳＳＨＹ 对异丙苯的裂解影响不大，很弱的Ｂ 酸就能催化此反应。用连续微反在３００ ℃考察ＨＹ 和ＨＹ０１ 对异丙苯的反应表明，ＨＹ０１ 失活速率下降，说明用Ｋ２ＳＯ４ 溶液改性ＨＹ

The acidities of HY, USHY and SSHY zeolites were modified by K 2SO 4 solution , the acid strength and acid amount of zeolites could be controled by adjusting the concentration and temperature of K 2SO 4 solution and the frequency of exchange. After HY, SSHY and USHY were once exchanged by 0.001 mol/L K 2SO 4 solution at 40℃, in HY and SSHY n -heptane cracking reaction at 300℃ could be avoided but USHY could cause n -heptane cracking. Modified HY and SSHY might be used for isomeric change of hydrocarbon. The measuring of acid strength indicated that the cracking performance not only has something to do with acid strength but also with the tye of acidity and orther factors. Moderate strength acidities of HY, SSHY and USHY could be prepared with 0.01～0.1 mol/L K 2SO 4 solution by exchanging once at 40℃. Modified HY, USHY and SSHY affected a little on the cracking reaction of cumene, and very weak Bronsted acid could catalyze the reaction. When HY and HY 01 were used as catalysts for cumene cracking in piston-flow tubular reactor at 300℃, results showed that deactive rate of HY 01 was declined and life span of HY 01 could be prolonged.