Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.706595
Title: Towards a low temperature, liquid phase methyl methacrylate process through mechanism-guided process design
Author: Beaumont, Michael
ISNI:       0000 0004 6057 9130
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2015
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Abstract:
A liquid (slurry) phase, base-catalysed process for the production of methyl methacrylate from methyl propanoate and formaldehyde has been developed, that runs at temperatures around 200 °C below the current, heterogeneous process (160-180 °C vs. 330-360 °C) running at ALPHA-1, a commercial, methyl methacrylate-producing chemical plant. Initially, caesium carbonate was used as the base, however fast deactivation of this base, producing hydroxide, results in the formation of inactive bases, caesium propanoate and caesium methacrylate from methyl esters. Through understanding of the mechanism of base deactivation, a new base catalyst, caesium methylcarbonate, was developed that does not act as a source of hydroxide. Understanding of the mechanisms of the condensation reaction, base deactivation and formaldehyde decomposition has allowed a system to be developed that achieves high conversions of methyl propanoate with excellent selectivity (up to 43 % conversion with up to 99.5 % selectivity on methyl propanoate, compared with 18 % conversion at 93 % selectivity in the current process). The system requires a polar, aprotic solvent to increase the activity of the base catalyst and high temperature addition is essential for high selectivity on formaldehyde. The caesium methylcarbonate is slowly deactivated through reaction of methyl esters with water, the co-product of the condensation reaction, to caesium propanoate and caesium methacrylate. For this reason, systems for the recycling to these methyl esters and caesium methylcarbonate have been developed so that multiple turnovers on caesium can be achieved through reaction-regeneration cycles. Regeneration of the active base can be achieved in a separate process step using carbon dioxide and methanol, to effectively reverse the equilibrium by which hydrolysis occurs, or with an in situ method using dimethyl carbonate as a sacrificial scavenger. A patent has been submitted to cover the work in this thesis and work on this project is continuing at Lucite International, the sponsors of this PhD studentship. This process is under active consideration for scale up and commercialization.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.706595  DOI: Not available
Keywords: QD Chemistry
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