An Innovative Method for the Synthesis of Dialkyl Carbonate, a ‘Green’ Chemical
Highlights: Industrial collaboration on challenging chemical synthesis work requiring significant planning, literature research and execution skills. Chemical characterisation by IR and NMR spectroscopy.
Dr Vuong performed this work as the Principal Project Researcher when working as an ICL Research Fellow (ICL: Israel Chemical Limited) at Dow Centre for Sustainable Engineering Innovation, The University of Queensland, UQ. The research team at UQ was asked by ICL to propose a research project aimed at utilising bromine in the production of commercial chemicals. ICL is one of the top five of largest producers of bromine. Scoping work suggested potential to produce dimethyl carbonate via carbonyl bromide intermediate formed by the reaction between bromine and carbon monoxide. Dimethyl carbonate is a widely used industrial chemical, it is the most significant amongst dialkyl carbonates. Approximately 50% of manufactured Dimethyl carbonate is used in the production of diphenyl carbonate as required for polycarbonate synthesis. Dimethyl carbonate is considered as a potential ‘green’ solvent and the preferred replacement for many volatile organic compounds. Dimethyl carbonate, when used as a fuel additive can significantly decrease particulate emissions and can be added to existing fuel formulation. A lower production cost of dimethyl carbonate could enable greater use as a green solvent, fuel additive and facilitate a more effective method producing isocyanate (i.e. polyurethane production).
Over the course of nearly one year with numerous experiments using different light sources, different surface catalysts to facilitate the reaction between bromine and carbon monoxide to form carbonyl dibromide. It was found dialkyl carbonate (e.g. dibutyl carbonate) could be synthesised yields up approximately 25% under mild conditions at 5 – 25 °C through in situ generated carbonyl dibromide on porous glass. The carbonyl dibromide intermediate was observed by Fourier Transformed Infrared Spectroscopy (FTIR). Further process gains could be possible if the reaction were to be conducted in a reactive distillation. Technoeconomic analysis, however, was not supportive for the commercialisation of this innovative synthesis route. The research was published in the prestigious journal, ACS Sustainable Chemistry & Engineering.
Publication: K. Q. Vuong, R. Effenberger, J. Zilberman, S. Smart, C. M. Williams and E. W. McFarland. Dialkyl Carbonate Synthesis via In Situ Generated Carbonyl Dibromide on Porous Glass. ACS Sustainable Chemistry & Engineering, 2017, 5(9), 7492-7495.