The preconditions were fixed by DSM:
Targets:
-ethylene yield 70% per pass,
-catalyst productivity higher than 0.2 kg ethylene/kg catalyst. h,
-P 2-3 atm in final testing,
-use of oxygen in stead of air
-complete conversion of oxygen,
-dilution preferably with steam
Conditions:
A set of starting elements is chosen and as well as the reaction conditions:
-T: 400-650 oC,
-P: 1 bar,
-ethylene ratio between 2 and 8,
-ethane concentration between 5 and 20% and
-contact time between 0.1 and 1 g.s/ml
Preliminary parallel testing and optimisation of ODHE catalytic materials for best performance at low temperatures applying the evolutionary approach is in progress. So far 4 generations each comprising 60 catalytic materials have been tested in the available 64-channels ceramic reactor under conditions as defined in WP1 (5 # conditions each).
Key data of the reactor set-up:
-64-channels reactor module
-inner diameter of a single reactor channel: 5.0 mm
-nearly constant temperature and flow in all reactor channels
-inert reactor material (ceramic)
-channel effluent to be analysed selected by multi position valves located in an air-heated box
-After testing of 4 generations of ODHE catalytic materials for the following results have been obtained:
-The best support for eggshell catalytic materials of the given pool of elements
is a-Al2O3 with a particle size of 250 -350 mm.
- So far the main components, which show a good performance, are: Cr, Co, Mn, Au
- Of minor importance for the catalyst activity are: Zr, Cu, Ga
- At standard conditions the best catalyst after 4 generations exhibits a ethylene yield of 16.5%
- No convergence of the combinatorial process occurred after 4 generations.