DISS. ETH No. 15376 STUDY OF ASPECTS OF DEEP HYDRODESULFURIZATION BY MEANS OF MODEL REACTIONS A dissertation submitted to the SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH for the degree of Doctor of Technical Sciences presented by MARINA EGOROVA Master of Science in Chemistry, Novosibirsk State University born 05.05.1976 citizen of Russia accepted on the recommendation of Prof. Dr. R. Prins, examiner Prof. Dr. A. Wokaun, co-examiner Zurich, 2003 To my husband Valeri and my parents Contents Abstract .................................................................................................................. V Zusammenfassung............................................................................................ VIII Chapter 1. Deep Desulfurization of Oil Refinery Streams.............................1 1.1 Hydrotreating in refining...........................................................................................1 1.2 Deep hydrodesulfurization ........................................................................................5 1.3 Catalytic HDS technologies ......................................................................................6 1.3.1 Conventional HDS............................................................................................6 1.3.2 Advanced HDS.................................................................................................7 1.3.2.1 Advanced HDS catalysts ......................................................................8 1.3.2.2 New reactor systems.............................................................................9 1.3.2.3 Combination of hydrotreating with other reactions............................10 1.3.2.4 Catalytic distillation............................................................................11 1.4 Monolith reactor/catalysts for HDS of refinery streams .........................................12 1.5 Conclusion...............................................................................................................15 1.6 References ...............................................................................................................16 Chapter 2. Structure of Sulfide Catalysts .......................................................21 2.1 Introduction ................................................................................................................21 2.2 Structure of the catalyst ..............................................................................................22 2.2.1 Structure of the oxidic catalyst precursor.......................................................22 2.2.2 Structure of the sulfidic catalyst .....................................................................23 2.2.3 Nature of active sites ......................................................................................28 2.3 References ..................................................................................................................33 I Chapter 3. Experimental .................................................................................... 37 3.1 Model compounds...................................................................................................... 37 3.1.1 S-containing molecules.................................................................................. 37 3.1.2 N-containing molecules ................................................................................. 40 3.2 High-pressure set-up .................................................................................................. 43 3.3 Catalysts preparation.................................................................................................. 45 3.4 Product analysis ......................................................................................................... 46 3.4.1 Pulsed flame photometric detector................................................................. 47 3.5 References.................................................................................................................. 48 Chapter 4. On the Role of β Hydrogen Atoms in the Hydrodenitrogenation of 2-Methylpyridine and 2-Methylpiperidine ........ 51 4.1 Introduction................................................................................................................ 51 4.2 Experimental .............................................................................................................. 53 4.3 Results........................................................................................................................ 54 4.3.1 HDN of 2-methylpyridine.............................................................................. 54 4.3.2 HDN of 2-methylpiperidine........................................................................... 55 4.3.3 Comparison of piperidine, 2-methylpiperidine, and 2,6-dimethylpiperidine..57 4.3.4 HDN of 1-aminohexane................................................................................. 60 4.3.5 HDN of 2-aminohexane................................................................................. 62 4.4 Discussion .................................................................................................................. 63 4.5 Conclusion ................................................................................................................. 67 4.6 References.................................................................................................................. 68 Chapter 5. Mutual Influence of the HDS of Dibenzothiophene and HDN of 2-Methylpyridine.................................................................................................. 71 5.1 Introduction................................................................................................................ 71 5.2 Experimental .............................................................................................................. 73 5.3 Results........................................................................................................................ 73 5.3.1 HDS of dibenzothiophene.............................................................................. 73 5.3.2 Inhibition of the HDS by N-containing molecules ........................................ 76 5.3.3 Effect of H2S on the HDN of 2-methylpyridine ............................................ 79 II 5.3.4 Influence of DBT on the HDN of N-compounds ...........................................82 5.4 Discussion...................................................................................................................84 5.5 Conclusion..................................................................................................................89 5.6 References ..................................................................................................................90 Chapter 6. Promotion Effect of 2-Methylpiperidine on the Direct Desulfurization of Dibenzothiophene over NiMo/γ-Al2O3 ............................93 6.1 Introduction ................................................................................................................93 6.2 Experimental...............................................................................................................95 6.3 Results ........................................................................................................................95 6.4 Discussion.................................................................................................................100 6.5 Conclusion................................................................................................................102 6.6 References ................................................................................................................103 Chapter 7. Competitive HDS of 4,6-Dimethyldibenzothiophene, HDN of 2- Methylpyridine and Hydrogenation of Naphthalene over sulfided NiMo/γ- Al2O3 .....................................................................................................................105 7.1 Introduction ..............................................................................................................105 7.2 Experimental.............................................................................................................106 7.3 Results ......................................................................................................................107 7.3.1 HDS of 4,6-dimethyldibenzothiophene........................................................107 7.3.2 Influence of N-containing molecules on HDS .............................................109 7.3.3 Influence of S-containing molecules on HDN .............................................111 7.3.4 Effect of solvent on HDS..............................................................................113 7.3.5 Effect of naphthalene on HDS......................................................................113 7.3.6 Influence of S-containing molecules on hydrogenation...............................114 7.4 Discussion.................................................................................................................115 7.5 Conclusion................................................................................................................124 7.6 References ................................................................................................................124 III Chapter 8. Hydrodesulfurization of Dibenzothiophene and 4,6- Dimethyldibenzothiophene