Controlled pressure hydrothermal treatment of odh catalyst
AssigneeNOVA Chemicals (International) S.A.
InventorsVasily Simanzhenkov, Xiaoliang Gao, David Jeffrey Sullivan, Hanna Drag, Marie Annette Barnes
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Abstract
The preparation of an oxidative dehydrogenation catalyst comprising Mo, V, Nb and Te using a hydrothermal step the activity and reproducibility of the catalyst is improved by conduction the hydrothermal step at higher pressures while permitting gaseous products to leave the reactor. In some instances a condenser may be upstream of the pressure relief valve.
Claims24
A process for synthesis of a catalyst for oxidative dehydrogenation of paraffins via a hydrothermal treatment comprising:
- i) preparing an aqueous slurry comprising Mo, V, Nb and Te salts in a molar ratio of metal elements 1:0.3 to 3;
- 0.05 to 0.25;
- and 0.08 to 0.2 at a temperature from 25° C. to 80° C.;
- ii) heating slurry in a reactor to a temperature from 80° to 220° C. at a pressure equal or above the saturated water vapor pressure at the corresponding reaction temperature, for a period of time not less than 1 hour with agitation and simultaneous removal of gaseous byproduct species produced during the reaction.
- iii) letting the reactor cool and depressurizing the reactor and recovering the catalyst as a solid.
The process according to 4, wherein the condenser is operated at a temperature above 0° C. and below reaction temperature.
The process according 1, wherein the gaseous species are removed from the reactor using one or more methods selected from gas absorption, gas adsorption, membrane separation, and chemicals transformation.
An oxidative dehydrogenation catalyst having the empirical formula as measured by PIXE:
- Mo1.0V0.32-0.49Te0.10-0.17Nb0.14-0.17Od
- where d is a number to satisfy the valence of the oxide.
A method for the oxidative dehydrogenation of a mixed feed comprising ethane and oxygen in a volume ratio from 70:30 to 95:5 and optionally one or more C3-6 alkanes or alkenes and oxygenated species including CO and CO2 at a temperature less than 400° C., a gas hourly space velocity of not less than 100 hr−1, and a pressure from 0.8 to 7 atmospheres comprising passing said mixture over an oxidative dehydrogenation catalyst having the empirical formula as measured by PIXE:
- Mo1.0V0.32-0.49Te0.10-0.17Nb0.14-0.17Od
- where d is a number to satisfy the valence of the oxide wherein the molar ratio of Mo:V in the catalyst is from 1:0.32 to 1:0.42 as measured by PIXE.
Dependencies are inferred from the claim text.