Zeolit ZSM-5 ve türevlerinin sentezi ve karakterizasyonu
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Dosyalar
Tarih
2013
Yazarlar
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Yayıncı
Hatay Mustafa Kemal Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, ZSM türevi katalizörler sentezlenmiş ve sentezlenen zeolitlerin katalitik parçalamadaki etkileri araştırılmıştır. ZSM türevleri; sentez süresi, sentez yöntemi ve kalsinasyon sıcaklıkları değiştirilerek sentezlenmiştir. Sentez bileşimi sabit tutularak gerçekleştirilen denemelerde ultrasonik yöntem ve hidrotermal yöntem karşılaştırılmıştır. Sentez yönteminin değiştirilmesiyle iki farklı ZSM türevi sentezlenmiştir. Kullanılan ultrasonik yöntemde; 20 dakikalık düşük sıcaklık ile gerçekleştirilen sentez sonucunda, beta zeolit elde edilmiştir. Diğer bir yöntem olan hidrotermal yöntemde ise 72 saatlik yüksek sıcaklık ile gerçekleştirilen sentez sonucunda ZSM-5 türü zeolit elde edilmiştir. X-Ray Kırınım (XRD) desenleri ve Taramalı Elektron Mikroskobu (SEM) görüntüleri, ZSM-5 zeolitlerde; faz saflığının ve kristal yapının uzun sentez süresi sonucunda oluştuğunu ve kalsinasyon sıcaklık değişimlerinden etkilenmediklerini tespit edilmiştir. Beta zeolitler de ise; kristal yapının ve faz saflığının kalsinasyon sıcaklığına bağlı olduğu tespit edilmiştir. Yüksek kalsinasyon sıcaklığına maruz bırakılan ürünlerde kristal yapının oluştuğu belirlenmiştir. Elde edilen ürünlerin katalitik performanslarının tespiti için katalitik parçalama deneyleri yapılmıştır. Denemelerin karşılaştırılabilmeleri için katalizörsüz olarak termal parçalama gerçekleştirilmiştir. Bunun haricinde; CaO, Al2O3, SiO2, doğal zeolit, sentezlenen beta zeolit ve sentezlenen ZSM-5 katalizörleri eşliğinde de parçalama deneyleri yapılmıştır. Yapılan deneysel çalışmaların sonuçları karşılaştırıldığında; sentezlenen ürünlerin katalitik verimleri diğerlerine göre oldukça yüksek çıkmıştır. Sentezlenen ZSM-5 ve beta zeolit katalizörlüğünde % 70 üzerinde verim elde edilmiştir.
In this study, ZSM cataysts were synthesized and the effects of synthesized zeolite in catalytic cracking were investigated. ZSM types were synthesized by varying synthesis time, synthesis method and calcination temperatures. The composition of the synthesis was kept constant and than compared with ultrasonic method and hydrothermal method. Two different ZSM derivatives were synthesized with changing the synthesis method. Beta zeolite was obtained as a result of the synthesis with low temperature in 20 minutes with using of ultrasonic method. On the other hand, ZSM-5 zeolite was achieved at the end of the synthesis with high temperature in 72 hours with using of hidrotermal method. The X-Ray Powder Diffraction (XRD) patterns and Scanning Electron Microscopy (SEM) images of ZSM-5 zeolites showed the crystal structure and phase purity of ZSM-5 increased with increase in synthesis time and not affected by the calcination temperature. Otherwise, the crystal structure and phase purity of beta zeolite was increased with increase in calcination temperature. To determine the catalytic performances of the products, the catalytic cracking processes were performed. First of all, thermal cracking was realized without catalyst for comparison with the others. Then, catalytic cracking was carried out with CaO, Al2O3, SiO2, natural zeolite, ZSM-5 and beta zeolite. The compairing of experimental results, the catalytic efficiency of the synthesized products were higher than the others. Yield of over 70 % was obtained with synthesized ZSM-5 and zeolite beta.
In this study, ZSM cataysts were synthesized and the effects of synthesized zeolite in catalytic cracking were investigated. ZSM types were synthesized by varying synthesis time, synthesis method and calcination temperatures. The composition of the synthesis was kept constant and than compared with ultrasonic method and hydrothermal method. Two different ZSM derivatives were synthesized with changing the synthesis method. Beta zeolite was obtained as a result of the synthesis with low temperature in 20 minutes with using of ultrasonic method. On the other hand, ZSM-5 zeolite was achieved at the end of the synthesis with high temperature in 72 hours with using of hidrotermal method. The X-Ray Powder Diffraction (XRD) patterns and Scanning Electron Microscopy (SEM) images of ZSM-5 zeolites showed the crystal structure and phase purity of ZSM-5 increased with increase in synthesis time and not affected by the calcination temperature. Otherwise, the crystal structure and phase purity of beta zeolite was increased with increase in calcination temperature. To determine the catalytic performances of the products, the catalytic cracking processes were performed. First of all, thermal cracking was realized without catalyst for comparison with the others. Then, catalytic cracking was carried out with CaO, Al2O3, SiO2, natural zeolite, ZSM-5 and beta zeolite. The compairing of experimental results, the catalytic efficiency of the synthesized products were higher than the others. Yield of over 70 % was obtained with synthesized ZSM-5 and zeolite beta.
Açıklama
Anahtar Kelimeler
Kimya, Chemistry ; Kimya Mühendisliği, Zeolit sentezi, ZSM-5, Beta zeolit, katalitik parçalama, katalizör, Synthesis of zeolite, ZSM-5, zeolite Beta, catalytic cracking, the catalyst
