化学反应工程与工艺
化學反應工程與工藝
화학반응공정여공예
CHEMICAL REACTION ENGINEERING AND TECHNOLOGY
2015年
2期
142-149
,共8页
纳米Beta沸石%合成%表征%异丙苯%烷基化
納米Beta沸石%閤成%錶徵%異丙苯%烷基化
납미Beta비석%합성%표정%이병분%완기화
nano-Beta zeolite%synthesis%characterization%cumene%alkylation
合成了纳米Beta沸石，并采用X射线衍射（XRD）、透射电镜（TEM）、比表面（BET）、程序升温脱附（NH3-TPD）以及吡啶-红外光谱（Py-IR）等方法对其结构和酸性进行了表征。比较了纳米Beta和常规大晶粒Beta沸石的催化性能，对纳米Beta沸石催化烷基化的关键参数进行了优化。结果表明：在硅铝物质的量比为25～30时，所合成的纳米Beta沸石具有较高的结晶度，晶粒尺寸在20 nm左右。同常规Beta沸石相比，纳米Beta沸石具有更大的BET比表面积和孔容，其比表面积可达600 m2/g，总孔容达0.42 cm3/g，介孔和大孔贡献超过50%。纳米Beta沸石具有较高的总酸量和B酸含量。作为苯和丙烯的烷基化催化剂，纳米Beta沸石具有更好的反应稳定性和选择性。在苯烯比3.0，反应温度150～160℃的条件下，异丙苯选择性可达89%，杂质正丙苯含量可降到极低水平。在工业试验中，纳米Beta沸石也表现出良好的综合性能，催化剂的稳定性和选择性优于同类Beta沸石催化剂。
閤成瞭納米Beta沸石，併採用X射線衍射（XRD）、透射電鏡（TEM）、比錶麵（BET）、程序升溫脫附（NH3-TPD）以及吡啶-紅外光譜（Py-IR）等方法對其結構和痠性進行瞭錶徵。比較瞭納米Beta和常規大晶粒Beta沸石的催化性能，對納米Beta沸石催化烷基化的關鍵參數進行瞭優化。結果錶明：在硅鋁物質的量比為25～30時，所閤成的納米Beta沸石具有較高的結晶度，晶粒呎吋在20 nm左右。同常規Beta沸石相比，納米Beta沸石具有更大的BET比錶麵積和孔容，其比錶麵積可達600 m2/g，總孔容達0.42 cm3/g，介孔和大孔貢獻超過50%。納米Beta沸石具有較高的總痠量和B痠含量。作為苯和丙烯的烷基化催化劑，納米Beta沸石具有更好的反應穩定性和選擇性。在苯烯比3.0，反應溫度150～160℃的條件下，異丙苯選擇性可達89%，雜質正丙苯含量可降到極低水平。在工業試驗中，納米Beta沸石也錶現齣良好的綜閤性能，催化劑的穩定性和選擇性優于同類Beta沸石催化劑。
합성료납미Beta비석，병채용X사선연사（XRD）、투사전경（TEM）、비표면（BET）、정서승온탈부（NH3-TPD）이급필정-홍외광보（Py-IR）등방법대기결구화산성진행료표정。비교료납미Beta화상규대정립Beta비석적최화성능，대납미Beta비석최화완기화적관건삼수진행료우화。결과표명：재규려물질적량비위25～30시，소합성적납미Beta비석구유교고적결정도，정립척촌재20 nm좌우。동상규Beta비석상비，납미Beta비석구유경대적BET비표면적화공용，기비표면적가체600 m2/g，총공용체0.42 cm3/g，개공화대공공헌초과50%。납미Beta비석구유교고적총산량화B산함량。작위분화병희적완기화최화제，납미Beta비석구유경호적반응은정성화선택성。재분희비3.0，반응온도150～160℃적조건하，이병분선택성가체89%，잡질정병분함량가강도겁저수평。재공업시험중，납미Beta비석야표현출량호적종합성능，최화제적은정성화선택성우우동류Beta비석최화제。
Nano-Beta zeolite was synthesized and characterized by various techniques, such as X-ray diffraction(XRD), transmission electron microscope(TEM), low-temperature isotherm of nitrogen adsorption and desorption(BET), NH3temperature-programmed desorption(NH3-TPD) and pyridine infrared spectroscopy(Py-IR). The catalytic performance of nano-Beta were also investigated in comparing with that of conventional Beta with large crystal size and the key parameters of alkylation were optimized in order to reach best performance in industrial cumene process. The results showed that the nano-Beta with molar ratio of SiO2 to Al2O3 25-30 had higher crystallinity and very small crystal size about 20 nm. Compared to conventional Beta with large crystal size, the nano-Beta had much larger BET surface area of 600 m2/g and higher pore volume of 0.42 cm3/g, which mainly came from mesopore and macropore, and possessed higher concentration of total acid sites and Bronsted acid sites. As catalyst for alkylation of benzene with propylene, nano-Beta zeolite was more stable and more selective. Under the conditions of benzene to propylene molar ratio of 3.0 and reaction temperature of 150-160℃, nano-Beta zeolite exhibited the best catalytic performance. Cumene selectivity reached as high as 89% and impurity, especially,n-propylbenzene decreased to very low level. During long term industrial test, nano-Beta catalyst also had much longer life span and higher selectivity than conventional Beta.
