Return to the future
Recent developments in the electrochemical synthesis of ethylene oxide seem to offer interesting perspectives for a highly selective industrial process, free of CO2 emissions, where ethylene, water and electricity are the only consumables, and valuable Hydrogen can be recovered. Combined with another process generating ethylene from CO2 the route CO2 to ethylene oxide becomes conceivable. The article also highlights the progress possible with a clever use of existing knowledge.
In these columns I have repeatedly advocated the importance of recurring to the past to get inspiration for the future. Recently I came across two developments that seem to confirm, at least conceptually, that I may be right.
I refer to the full sustainable production of ethylene oxide (EO).
EO was first discovered by the French chemist Charles Adolphe Wurtz (1817-1884) in 1859 by dehydrochlorination of 1-chloro-2-hydrovyethanol (ethylene chlorohydrin), a process still occasionally used for laboratory synthesis.
EO has become a fundamental pillar of the chemical industry, used in a variety of applications: detergents, solvents, glycols and polyethylene glycols, medical equipments disinfection, thermobaric weapons. About 20 million metric tons of ethylene oxide per year are produced, by reacting ethylene and oxygen over a silver catalyst at temperatures of 200–300 °C and pressures up to 3 Mpa. Although the process is more cost-effective compared with other synthetic routes it is highly polluting: for each ton of ethylene oxide produced almost one ton of CO2 is released to the environment, partly be ...