New energy-efficient process routes in industry: the one-step conversion of methane to ethylene, methanol and formaldehyde

Project Information

Grant agreement ID: JOE3950010

Project closed

Start date 1 January 1996

End date 30 June 1998

Funded under

• Specific programme for research and technological development, including demonstration in the field of non-nuclear energy, 1994-1998

Total cost € 0,00

EU contribution No data

Coordinated by

University of Patras
Greece

Exploitable results

New energy-efficient process routes in industry: the one-step conversion of methane to ethylene, methanol and formaldehyde

The main goals of the Project were: to study the scale-up of a novel oxidative coupling of methane (OCM) reactor-separator (Science 264, 1583, 1994) for ethylene production, and to construct and test similar reactor-separator units for the production of methanol/formaldehyde from methane. Both goals have been met during the Project. The OCM reactor-separator has been successfully scaled up from the microreactor unit described in the Science publication (catalyst mass 0.1 g, molecular sieve mass 2-3 g, gas feed flowrate 3 cm3 STP/min) to a large bench scale unit (catalyst mass 4 g, molecular sieve mass 40 g, gas feed flowrate 250 cm3 STP/min, recycle flowrate 900 cm3 STP/min). This near 100-fold scale-up in gas feed flowrate has been achieved without any significant loss in C2 hydrocarbon selectivity and yield. This C2 yields up to 53% and C2H4 yields up to 45% have been obtained. It is the first time that such high C2 and C2H4 yields are obtained at such high gas flowrates (240 cm3 STP/min). The same concept was used to study and scale-up the partial oxidation of methane to methanol and formaldehyde (MMF process). Maximum formaldehyde yield of 6% at a selectivity of 45% was obtained at feed flowrates of 30 cm3 STP/min using 2 g of catalyst, 20 g of trapping material and recycle flowrates of 380 cm3 STP/min. Although the maximum achieved formaldehyde yield was significantly lower than that originally anticipated on the basis of literature values reported for single pass (no recycle) operation, still the achieved value (6%) is the highest reported in the literature. Since our best single pass formaldehyde yield was of the order of 1% the values achieved with recycle operation (6%) show the significant advantages of the recycle reactor separator. In the course of this Project significant advances were made both in terms of developing novel state-of-the-art catalysts for the OCM process as well as for the development of efficient trapping materials for the selective adsorption of ethylene at higher temperatures (250°C).