Skip to main content

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

Objective



Objectives

The partial oxidation of methane to ethylene/ethane and to methanol/formaldehyde is being investigated in a novel gas recycle reactor-separator. The units will employ a fixed-bed catalytic or electrocatalytic reactor with an optimized catalyst composition and an optimally designed swing-bed molecular sieve trap. The project is expected to demonstrate the technical feasibility of scale-up of the novel reactor-separator for the one-step oxidative coupling or partial oxidation of methane.

Technical Approach

The development of direct (one-step) and energy efficient process for the conversion of methane to ethylene and to methanol/formaldehyde has been a long-sought goal. Despite intensive research during the last twelve years, the maximum ethylene and formaldehyde yields obtained in laboratory-scale reactors until 1994 was of the order of 20% and 5% respectively.
In 1994, one of the participating research teams (University of Patras) developed a novel laboratory scale gas-recycle reactor separator which gave ethylene yields up to 85% for the oxidative coupling of methane (OCM)(Science 254, 1583, 1994). In this novel reactor-separator ethylene and ethane are trapped, and thus protected from further oxidation, in a molecular sieve trap in the recycle loop. They are released by subsequent heating of the molecular sieve trap. The above very encouraging results were obtained in a small microreactor (catalyst mass 0.1g molecular sieve mass 2-3g) able to handle up to 3 ccSTP/min of CH4.

The current objectives are:
1. To study the scale-up of the novel reactor-separator for ethylene production by building bench-scale units able to convert up to 1000 ccSTP/min of CH4 each to ethylene.
2. To construct and test a similar catalytic reactor-separator for the production of methanol/formaldehyde from methane (up to 1000 ccSTP/min).
Efficient state-of-the-art catalysts and molecular trapping materials are already being produced and tested by the project team and preliminary results have already shown a five-fold enhancement in formaldehyde yield relative to single-pass conditions using the novel-reactor separator concept.

Expected Achievements and Exploitation

The outputs of this project are:
- Specifications of the optimal catalyst, electrocatalyst and trapping materials for the novel reactor-separator units.
- Design, construction and operation of prototype reactor-separator units at flowrates on the order of 1 l/min.

The results will provide a firm technical basis for assessing the feasibility for developing new industrial processes for the one-step energy-efficient conversion of methane to ethylene and formaldehyde.

Coordinator

University of Patras
Address
Caratheodory St.1
26500 Patras
Greece

Participants (5)

IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
United Kingdom
Address
Prince Consort Road
SW7 2AZ London
Lube Processing Corporation
Greece
Address
10-12,Kifissias Street
15125 Amaroussio - Athens
Shell Research BV
Netherlands
Address
3,Badhuisweg
1003 AA Amsterdam
University of Cambridge
United Kingdom
Address
Lensfield Road
CB2 1EW Cambridge
Universität Karlsruhe (Technische Hochschule)
Germany
Address
12,Kaiserstrasse
76128 Karlsruhe