Hidrodesulfurisasi (HDS) tiofen menggunakan katalis Ni-Mo terimpregnasi pada ultra stable y-zeolite (USY)

HARJITO, Prof. Dra. Wega Trisunaryanti, M.S., Ph.D.Eng

2009 | Tesis | S2 Ilmu Kimia

Telah dilakukan uji aktivitas hidrodesulfurisasi (HDS) tiofen sebagai model senyawa heteroatom menggunakan katalis Ni-Mo/USY. Katalis dipreparasi dengan metode impregnasi kemudian dikalsinasi pada temperatur 550o C, oksidasi dan reduksi pada temperatur 400o C, masing-masing dengan gas nitrogen, oksigen dan hidrogen. Karakterisasi dilakukan dengan uji keasaman dengan adsorpsi amonia, spektrometri infra merah untuk jenis situs asam, metode difraksi sinar X (XRD) untuk uji kristalinitas dan Atomic Absorption Spectrophotometry (AAS) untuk penentuan kadar logam. HDS dilakukan dengan reaktor semi alir (semi flow-fixed bed reaktor) pada tempertur 350o C. Rasio katalis umpan 0,4 dengan aliran gas hidrogen 25 mL/min. Umpan diuapkan dalam penangas air dan dialiri gas hidrogen menuju ke reaktor. Gas hasil HDS dikondensasikan dalam campuran es-garam. Gas yang tidak terkondensasi dijebak dengan n-heksana. Kondensat dianalisis secara gravimetri sedangkan gas terlarut dalam n-heksana dianalisis dengan kromatografi gas (GC) dan kromatografi gas-spektrometer massa (GCMS). Hasil karakterisasi secara umum, impregnasi logam Ni-Mo meningkatkan keasaman katalis USY sebesar 4 mmol/g, bertambahnya jumlah situs asam Lewis dan peningkatan kristalinitas katalis USY. Hasil analisis AAS menunjukkan kadar Mo (77 ± 0,14)% dan kadar Ni (1,39 ± 0,03)% yang terembankan pada USY. Aktivitas katalitik HDS tertinggi sebesar 74,01% dicapai pada temperatur 350 oC. Hasil analisis GC menunjukkan adanya 11 macam senyawa yang terjebak dalam n-heksana dan dari analisis GC-MS dikenali dua diantaranya adalah isobutana dan isopentana sedangkan pada kontrol hasil GC maupun GC-MS negatif. Pada temperatur 350 oC tetapan laju reaksi HDS tiofen dengan katalis Ni-Mo/USY adalah 0,0488 s-1.

Hydrodesulfurization (HDS) of thiophene as a model of heteroatom compound using Ni-Mo/USY catalyst was carried out. The catalyst was prepared by impregnation method and calcined at 550o C, oxidized and reduced at 400o C, by flowing nitrogen, oxygen, and hydrogen gas, respectively. The characterization was conducted by acidity test using adsorption of ammonia, Fourier Transform- Infra Red (FTIR) Spectrometry to investigate the type of acid sites, X-Ray Diffraction (XRD) method to analyze crystalinity and Atomic Absorption Spectrophotometry (AAS) to determine the metal content. The HDS reaction was carried out by using semi flow-fixed bed reactor at 350oC. The feed-catalyst ratio was 0.4 with hydrogen flow rate of 25 mL/min. The feed was evaporated in water bath and flowed by hydrogen to reactor. The gas product was condensed in a saltice mixture. The uncondensed gas was trapped by n-hexane. The condensated was analyzed gravimetrically whereas the dissolved gas in n-hexane was analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectroscopy (GCMS). The characterization results, showed that impregnation of Ni-Mo metals increased acidity of 4 mmol/g, the number of Lewis acid sites and crystalinity of USY, the AAS result showed the content of Mo and Ni that was impregnated on the USY were (77 ± 0.14)% and (139 ± 0.03)%, respectively. The highest catalytic activity was 74.01% reached at 350 oC. The GC analysis results showed the existence of 11 kinds of compounds trapped in n-hexane, and the GC-MS analysis result recognized two compounds i.e. isobutane and isopentane whereas in control the gas product was not detected. At 350 oC, rate constant of thiophene HDS is 0.0488 s-1.

Kata Kunci : Hidrodesulfurisasi (HDS),Tiofen,Ni,Mo (USY),Impregnasi,Hydrodesulfurization (HDS),Thiophene,Ni-Mo/USY,impregnation