Green metrics analysis applied to the simultaneous liquid-phase etherification of isobutene and isoamylenes with ethanol over AmberlystTM 35

A case study of the green metrics analysis of several processes is described. The considered system is the simultaneous etherification of isobutene and isoamylenes with ethanol over AmberlystTM 35. Experimental results are compared under the green metrics methodology with those for the isolated ethyl tert-butyl ether and tert-amyl ethyl ether syntheses previously reported over acid ionexchange resins using different reaction batch devices and different synthesis pathways, such as the production of both ethers from tertiary alcohols and from ethanol. The best results, from an environmental point of view, were obtained for ether syntheses from olefins and ethanol in terms of the parameters measured in the green metrics analysis. A process allowing the separation of ethers from the product stream and the reactants recirculation has been proposed and simulated. The suggested process depicts a suitable alternative for the simultaneous production of tertiary ethers from pure olefin feed and their downstream implementation as greener fuel additives with environmental benefits.