H2S’ÜN ELEMENTEL KÜKÜRDE SEÇİCİ OKSİDASYONUNDA Ti-V-Cr ve Ti-V-Fe KATALİZÖRLERİ

Öz

Bu çalışmada kompleksleştirme yöntemiyle eşmolar oranda Ti-V-Fe ve Ti-V-Cr katalizörleri sentezlenmiş ve H₂S’ün seçici oksidasyon reaksiyonuyla elementel kükürt eldesindeki aktiviteleri incelenmiştir. Katalizörlerin katalitik aktiviteleri dolgulu kolon reaktör sisteminde farklı sıcaklık (200°C, 250°C, 300°C) ve stokiyometrik gaz (O₂/H₂S:0,5) bileşiminde incelenmiştir. Katalizörlerin yapısal özellikleri N₂ adsorpsiyon-desorpsiyon, XRD, TPR, SEM-EDS analizleri ile belirlenmiştir. Sentezlenen katalizörlerin mezogözenekli yapıya sahip olduğu tespit edilmiştir. Ti-V-Cr katalizörünün kristal yapısı TiO₂’in rutile fazı ve Cr₂O₃ bileşiklerinden oluşurken, Ti-V-Fe katalizörü kompleks bir kristal yapı sergilemiştir. Bu katalizörün yapısında Fe₂TiO₅, V₂O₅, FeV₂O₄, rutile TiO₂ ve Fe₂O₃ bileşikleri görülmüştür. Sentezlenen her iki katalizörle de 250°C reaksiyon sıcaklığında % 100 H₂S dönüşümü elde edilmiştir. Reaksiyon sıcaklığındaki artış ve azalış katalizörlerde elde edilen H₂S dönüşümünde azalmaya sebep olmuştur. Bunun yanı sıra çalışılan tüm şartlarda her iki katalizörle de oldukça yüksek (≥% 97) elementel kükürt seçiciliği elde edilmiştir.  Özellikle 200°C sıcaklıkta, yapısında kompleks bileşikleri içeren Ti-V-Fe katalizörü ile (% 73 H₂S dönüşümü) Ti-V-Cr katalizörüne kıyasla (% 51 H₂S dönüşümü) daha yüksek dönüşüm elde edilmiştir. 

Anahtar Kelimeler

• Katalizör,H2S,Seçici oksidasyon,elementel kükürt

Ti-V-Cr and Ti-V-Fe Catalysts for H2S Selective Oxidation to Elemental Sulfur

Öz

In this study, Ti-V-Fe and Ti-V-Cr catalysts were synthesized by complexation method and their activities were investigated for H₂S selective oxidation reaction to elemental sulfur. Structural properties of the catalysts were determined by N₂ adsorption-desorption, XRD, TPR, SEM-EDS analyzes. According to the analysis results, it has been found that the synthesized catalysts have a mesoporous structure. Ti-V-Fe catalyst exhibits a complex crystal structure, while the crystal structure of the Ti-V-Cr catalyst is comprised of the rutile phase of TiO₂ and Cr₂O₃ compounds. In this catalyst structure, Fe₂TiO₅, V₂O₅, FeV₂O₄, rutile TiO₂ and Fe₂O₃ compounds were observed. The catalytic activities of the catalysts were investigated in a packed column reactor system at different temperatures (200°C, 250°C, 300°C) and stoichiometric gas composition (O₂/H₂S:0.5). 100% H₂S conversion was obtained at 250°C reaction temperature with both catalysts synthesized. The increase and decrease in the reaction temperature led to a decrease in the conversion of H₂S obtained with the catalysts due to the increase in sulfur deposition in the catalyst structure. In addition, under all conditions studied, elemental sulfur selectivity was high (≥ 97%) with both catalysts. Espe,cially at 200°C, a higher conversion was obtained with Ti-V-Fe (73% H₂S conversion) catalyst which has complex compounds in the structure compared to Ti-V-Cr catalyst (51% H₂S conversion).

Anahtar Kelimeler

• Catalyst,H2S,Selective oxidation,Elemental sülfür

Kaynakça

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