Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Methanol amination over hydrothermally treated zeolites RHO and Modernite
Methylamines are important chemicals in many industrial processes. They have use as intermediates for the production of many compounds containing amino groups as well as being used on their own. The acid catalysed amination of methanol generally yields a thermodynamically controlled product distribu...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Chemical Engineering
2017
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613332263927808 |
|---|---|
| access_status_str | Open Access |
| author | Van Steen, Linda Heather Callanan |
| author2 | O'Connor, Cyril T |
| author_browse | O'Connor, Cyril T Van Steen, Linda Heather Callanan |
| author_facet | O'Connor, Cyril T Van Steen, Linda Heather Callanan |
| author_sort | Van Steen, Linda Heather Callanan |
| collection | Thesis |
| description | Methylamines are important chemicals in many industrial processes. They have use as intermediates for the production of many compounds containing amino groups as well as being used on their own. The acid catalysed amination of methanol generally yields a thermodynamically controlled product distribution. The equilibrium distribution for mono-, di-, and trimethylamine (MMA, DMA, and TMA), at 325°C and a molar methanol to ammonia ratio of 1, is 17, 21, and 62 mol % respectively. The market demand, on the other hand, is for about 33, 53, and 14 mol % MMA, DMA and TMA. Industrially, methylamines are formed by the reaction of methanol or dimethyl ether and ammonia over amorphous silica-alumina. This process involves large separation and recycle units which are both costly and energy intensive as the separation requires azeotropic distillation at 15 bar. Methylamines can be formed over other solid acid catalysts with definite crystal structures, namely zeolites. While being more active than amorphous silica-alumina, most zeolites do not show improved selectivity. Catalysts, which have, however, been reported to show improved selectivity to DMA, include zeolites Rho, ZK-5 and Chabazite. In addition, certain forms of hydrothermally treated Mordenite can produce nonequilibrium product distributions. The performance of Rho can also be improved with hydrothermal treatment. The objectives of this study were briefly as follows. Firstly, the question was asked as to which of the catalysts studied, viz. Rho and Mordenite, was the most suitable for the methanol amination reaction. The second objective was to find the optimal performance achievable from any catalyst using hydrothermal treatment. The third, and possibly most important, objective was to propose reasons for the changes caused to each catalyst by hydrothermal treatment. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/23806 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:27.383Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Department of Chemical Engineering |
| publisherStr | Department of Chemical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/23806 Methanol amination over hydrothermally treated zeolites RHO and Modernite Van Steen, Linda Heather Callanan O'Connor, Cyril T Van Steen, Eric Chemical Engineering Methylamines are important chemicals in many industrial processes. They have use as intermediates for the production of many compounds containing amino groups as well as being used on their own. The acid catalysed amination of methanol generally yields a thermodynamically controlled product distribution. The equilibrium distribution for mono-, di-, and trimethylamine (MMA, DMA, and TMA), at 325°C and a molar methanol to ammonia ratio of 1, is 17, 21, and 62 mol % respectively. The market demand, on the other hand, is for about 33, 53, and 14 mol % MMA, DMA and TMA. Industrially, methylamines are formed by the reaction of methanol or dimethyl ether and ammonia over amorphous silica-alumina. This process involves large separation and recycle units which are both costly and energy intensive as the separation requires azeotropic distillation at 15 bar. Methylamines can be formed over other solid acid catalysts with definite crystal structures, namely zeolites. While being more active than amorphous silica-alumina, most zeolites do not show improved selectivity. Catalysts, which have, however, been reported to show improved selectivity to DMA, include zeolites Rho, ZK-5 and Chabazite. In addition, certain forms of hydrothermally treated Mordenite can produce nonequilibrium product distributions. The performance of Rho can also be improved with hydrothermal treatment. The objectives of this study were briefly as follows. Firstly, the question was asked as to which of the catalysts studied, viz. Rho and Mordenite, was the most suitable for the methanol amination reaction. The second objective was to find the optimal performance achievable from any catalyst using hydrothermal treatment. The third, and possibly most important, objective was to propose reasons for the changes caused to each catalyst by hydrothermal treatment. 2017-02-01T10:45:50Z 2017-02-01T10:45:50Z 2000 2016-11-30T10:49:41Z Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/23806 eng application/pdf Department of Chemical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Chemical Engineering Van Steen, Linda Heather Callanan Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| thesis_degree_str | Doctoral |
| title | Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| title_full | Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| title_fullStr | Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| title_full_unstemmed | Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| title_short | Methanol amination over hydrothermally treated zeolites RHO and Modernite |
| title_sort | methanol amination over hydrothermally treated zeolites rho and modernite |
| topic | Chemical Engineering |
| url | http://hdl.handle.net/11427/23806 |
| work_keys_str_mv | AT vansteenlindaheathercallanan methanolaminationoverhydrothermallytreatedzeolitesrhoandmodernite |