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

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

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).

Keywords:

Catalyst, H2S, Selective oxidation, Elemental sülfür,

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