Scale up study of capillary microreactors in solvent-free semihydrogenation of 2‐methyl‐3‐butyn‐2‐ol

Abstract

warwick.ac.uk/lib-publicationsOriginal citation: Cherkasov, Nikolay, Al-Rawashdeh, Ma 'moun, Ibhadon, Alex O. and Rebrov, Evgeny V.. (2016) Scale up study of capillary microreactors in solvent-free semihydrogenation of 2-methyl-3-butyn-2-ol. Catalysis Today, 273 . pp. 205-212. Permanent WRAP URL:http://wrap.warwick.ac.uk/78678 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for-profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. Keywords: Semihydrogenation; catalytic coatings; microreactor; Palladium; alkynol; acetylene. Highlights:-Capillary reactors with a diameter of 0.53 and 1.6 mm were coated with a Pd/ZnO catalyst -The alkene selectivity above 97% was obtained in the hydrogenation of 2-methyl-3-butyn-2-ol -At a coating thickness of 6 µm, the onset of internal diffusion limitations was observed -A throughput of 28 kg/day per coated channel can be reached according to the reaction kinetics Graphical abstract:

Process Intensification of Alkynol Semihydrogenation in a Tube Reactor Coated with a Pd/ZnO Catalyst

“…The increased selectivity by 1-2% in the diluted solutions when compared solvent-free operation agrees with the previous literature data [41,48]. The likely reason is that the increasing absolute concentrations of MBE that was formed under solvent-free conditions result in higher MBE adsorption on the catalyst surface and a higher rate of subsequent hydrogenation into MBA.…”

“…The observed selectivity is notably higher than the one observed over the Pd catalysts supported on conventional supports, such as TiO2 or SiO2, where the selectivity reaches around 92% at a low conversion [24,49]. These data are in excellent agreement with the previous studies over Pd/ZnO catalysts [41,48] and are comparable to the best examples of MBY semihydrogenation reported in literature over more complex metal-poisoned bimetallic catalysts which show selectivity of in the range of 97-98% [28,32,36,[50][51][52].…”

“…The average diameter of the nanoparticles observed was 4.2 nm, which corresponded to a Pd dispersion of 28% using the calculation provided in reference [47]. diffraction studies in the literature [41,44,45]. However, the particles with the average diameter of 7 nm were observed in the diffraction patterns by Semagina et al [46], likely due to larger Pd nanoparticles and a higher ZnO crystallinity.…”

“…The smaller Pd nanoparticles are expected to result in broad peaks and the correspondingly low signal from the particles [24]. The Pd nanoparticles of comparable dimensions (4-6 nm) were also not observed over the ZnO support in powder X-ray diffraction studies in the literature [41,44,45]. However, the particles with the average diameter of 7 nm were observed in the diffraction patterns by Semagina et al [46], likely due to larger Pd nanoparticles and a higher ZnO crystallinity.…”

“…However, the catalyst-coated tubes were demonstrated so far only at the milligram [38] to 10 g a day throughput levels [28,36], which are not suitable for industrial applications [35,39,40]. We have extrapolated the experimental performance of the tube reactors wall-coated with the Pd/ZnO catalyst and showed that a throughput of above 4 kg a day is feasible in a single 5 m long 1.5 mm ID reactor in the solvent-free MBY semihydrogenation [41]. However, there is very little experimental evidence on the applicability of the catalyst-coated tube reactors at the kilogram throughput level, which covers the area of innovator-drug manufacturing scale.…”