2011Al-Ghamdiphd.Pdf

Al-Ghamdi, Khalaf (2011) An investigation of heterogeneous base catalysed acetone conversion. PhD thesis. http://theses.gla.ac.uk/2878/ Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Glasgow Theses Service http://theses.gla.ac.uk/ [email protected] 1 An investigation of heterogeneous base catalysed acetone conversion Khalaf Al-Ghamdi Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy School of Chemistry College of Science and Engineering 2011 2 Abstract A series of materials have been compared for their activity in the base catalysed condensation of acetone. Activities have been compared after extended times on stream (18 h) and under a H2 containing atmosphere at elevated pressure which is designed to mimic conditions applicable for the single stage transformation of acetone to MIBK. In general, catalysts without a strong hydrogenation function have been screened and so mesityl oxide is the dominant reaction product. However, 1%Pd5%MgO/SiO2 does exhibit high selectivity towards MIBK, demonstrating that single-stage conversion is possible under the conditions investigated. Catalytic activity is found to be a strong function of the material tested. However, when the influence of surface area is taken into account, a spectrum of area normalised conversion rates is evident. These rates were found to vary in the order 36.5% KNO3/Al2O3 > Li/MgO > 36.5% KNO3/ZrO2 > 36.5% KNO3/Zr(OH)4 > MgO derived from Mg(OH)2.MgCO3 > 14% KNO3/Al2O3 > MgO derived from Mg(OH)2 > 14% KNO3/Zr(OH)4 > ZrO2 > 14% KNO3/ZrO2 > Y-Zr(OH)4. When comparing materials produced from different precursors, differences in catalytic behaviour are apparent implying structure-sensitivity and/or the influence of different impurity contents. The role of dopant, additional phase level and precursor phase has also been examined demonstrating that all these parameters are important. 3 Table of contents I. Abstract……………………………...………………………….…………..….2 II. Table of contents……………………………………………….…………..…3 III. Auther’s Declaration…….………...…………………………...………….…6 IV. Acknowedegment…………………………………………………………......7 V. Publication……………………….………………………………...……….…..8 VI. Figures…………………………….……………………………………….…..9 VII. Tables…………………………………………………………………….…..18 Chapter 1 Introduction……………………………………..……………….……21 1.1 Catalyst………………………….…………………………….……….…….22 1.2 Aldol condensation reaction of acetone and synthesis of methylisobutylketone (MIBK)………………………..…………………..……..28 1.3 Mechanism of aldol condensation reaction of acetone over base catalyst………………….…..........................................................................37 1.4 Aims…………………………………………………….….……….…………41 1.5 References…………………………………………….….....……….………...42 Chapter 2 Experimental methods………………………….….…………..….........48 2.1 Catalyst preparation and characterization………………………………...…...49 2.1.1 X-ray diffraction (XRD)………………………….………..….….……….49 2.1.2 Thermal Analysis (TGA, DSC, DTA)…………………………………….51 2.1.3 TPD………………………………………..………………………….…...53 2.1.4 BET……………………………………….…………………………..…...55 2.1.5 SEM……………………………………..…………..……………………..56 2.1.6 GC……………………………………………..…..………....…………….56 2.1.7 Reactor…………………………………...…….....………………………...60 2.1.8 CHN Analysis…………………………………….……….………………..62 2.2 Catalyst preparation……………………………...……..……...............................63 2.3 Catalytic studies…………………………………...……..……………...……….66 2.4 References…………………………………………………..………………...….72 Chapter 3 Catalyst precursor and doping effects upon MgO 4 catalysed acetone…………………………………………………..………………….75 3.1 Introduction…………………………………….………….……………………….76 3.1.1 MgO………………………………………………………………..………....76 3.1.2 Li/MgO……………………………………………………………………....84 3.2 Results and discussion……………………………………………………………...89 3.2.1 MgO…………………………………………………………...……..…..........89 3.2.2 Li-MgO……………………………………………..……………….…...........96 3.3 Conclusion………………………………………………………………………....101 3.4 References………………………………………………………...………………..108 Chapter 4 Zirconia based catalysts for acetone conversion…………...……............113 4. Introduction……………………………………………….…………………...…….114 4.1. Zirconia………………………………………………….…………………...…….114 4.2 Results and discussion…………………………………………………...…...........142 4.2.1 ZrO2………………………………………………………………………...…142 4.2.2 KNO3/ZrO2……………………………………………………………………148 4.2.3 KNO3/Zr(OH)4………………………………………………………………..157 4.2.4 Y-Zr(OH)4…………………………………………………………………….164 4.3 Conclusion…………………………………………………………………………..170 4.4 References………………………………………………………………………..…172 Chapter 5 Alumina supported potassium nitrate derived catalysts for acetone conversion……………………………………………………….176 5.1 Introduction…………………………………………………………………………..177 5.2 Results and discussion………………………………………………………………..184 5.3 Conclusion………………………………………………………………………........190 5.4 References………………………………………………………………….…...........192 5 Chapter 6 Silica supported metal oxide catalysts for acetone Conversions……………………………………………………..……………………….193 6. Introduction……………………………………...…………………………………….194 6.1 Silica…………………………………………...………….…………………............194 6.2 Results and discussion……………………………………………………………..…203 6.3 Conclusion…………………………………….……………………………………...213 6.4 References………………………….…………………………………………..…….215 Chapter 7 Conclusions and future work………………………………..……………..217 6 Declaration I declare that, except where explicit reference is made to the contribution of others, that this dissertation is the result of my own work and has not been submitted for any other degree at the University of Glasgow or any other institution. Signature: Name: Khalaf Jamaan Alghamdi 7 Acknowledgment Firsty, I woud like to thank my supervisor Dr. Justin Hargreaves for his great support, help, guidance and enthusiasm during my study at the University, he always tries to provide a help not only in my study but also in my life in the UK. Gratitude is extended to Prof. David Jackson for his kind help and support. I also would like to thank Prof. C. Wilson for his advice and support during my study. Thank you to Dr. Joe Gamman and Dr. Dan Rosenburg for their help in my experimental work. I also wish to say thank you to Mr. Ron Spence for his kind help and support in my Lab work. Thank you to Mr. Andy Monaghan for his kind help and support. Thank you to Mr. J. Gallagher for his help in SEM experiments. Thank you to Mrs. Kim Wilson for her help with the CHN analysis. Thank you to every person who provided me or my family any kind of help in the UK and I wish them every success. Thanks to my parents, wife and kids. Thank you very much to all. Khalaf 8 Publications K. Alghamdi, J. S. J. Hargreaves, and S. D. Jackson, Base catalysis with metal oxides. In: S. D. Jackson, and J. S. J. Hargreaves (eds.) Metal Oxide Catalysis. Wiley- VCH, Weinheim, Germany, ISBN 9783527318155 (2009). 9 Figures Fig. 1.1.1 Base catalysts types according to the acidity function H- value………………25 Figure. 1.1.2 A schematic of a three step MIBK process built-up by Chemische Industrie [44]…………………………………………………………………………………….…31 Fig.1.1.3 The Deutsche Texaco one step MIBK process ………………………………..32 Fig. 1.1.4 Main mechanism of the aldol condensation reaction of acetone over base catalyst……………………………………………………………………………...….…38 Fig. 1.1.5 Flego and Perego mechanism of the aldol condensation reaction of acetone over acid catalyst ………………………………………………………..……………..............39 Fig. 1.1.6 Production of isophorone via intermediate steps……………………................40 Fig. 2.1.1 X-ray diffraction.…………...…………………………………………………..50 Fig. 2.1.3 Glass rig CO2-TPD scheme used in this work……………………….…………54 Fig. 2.1.6 Standard component GC calibration curves………………………..…………...59 Fig. 2.1.7 A schematic of the microreactor used ………………………………………….61 Fig. 2.2.1 The point of zero charge (PZC) on an oxide surface…………………………...64 Fig. 2.3.1 Aldol condensation reaction of acetone over base catalyst……………………67 Fig. 2.3.2 The effect of the pre-treatment process upon acetone conversion (300 oC, 5 bar pressure)………………………………………………………………………………….69 Fig. 2.3.3 The effect of the pre-treatment temperature on acetone conversion at 350 oC and 450 oC after 18 h of time on stream………………………………………………………70 Fig. 2.3.4 The effect of the pre-treatment temperature on product selectivity at 350 oC and 450 oC after 18 h of time on stream………………………………………………………70 Fig. 2.3.5 Reproducibility test over 5% CaO/SiO2 catalyst, after 18 h of the reaction, at 200 oC reaction temperature and 5 bar………………………………………….……..………71 Fig. 3.1 Low coordination ions exhibited on the MgO surface……………….………….76 Fig. 3.2 Crystal structure of brucite ………………………………………..……………..79 Fig. 3.3 High index plane aggregates of MgO microcublets………………………………80 Fig. 3.4 MgO surface energy vs OH surface coverage of MgO(100) and MgO(111)…......81 10 Fig. 3.5 Transmission electron micrograph (TEM) image of non-calcined MgO ribbon residue after use as a catalyst. (b) Phase contrast electron micrograph of MgO ribbon residue the post-reaction sample. ………………….…………………………………….81 Fig. 3.6 Transmission electron micrograph of MgO prepared from Mg(OH)2 prior to use as a catalyst………………………………………………………………………………….82 Fig. 3.7 a) High magnification transmission

Load more