Catalyst composition for the selective conversion of synthesis gas to light olefins
AssigneeDow Global Technologies LLC
InventorsThomas Davidian, Matthijs Ruitenbeek, Adam Chojecki, Adrianus Koeken
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Abstract
A catalyst composition and process for preparing it and for using it to enhance the selectivity to light (C2 to C3) olefins in a Fischer-Tropsch conversion of synthesis gas is disclosed. The catalyst composition is an iron-based catalyst on an yttria/zirconia support. In a Fischer-Tropsch reaction the selectivity to ethylene may be enhanced by at least 20 mole percent and to propylene by at least 4 mole percent, in comparison with use of an otherwise identical catalyst that is free of yttria, in an otherwise identical Fischer-Tropsch reaction.
Claims8
A catalyst for use in converting synthesis gas into olefins, comprising
- iron, and optionally, an alkali metal, alkaline earth metal or a combination thereof,
- on a support comprising zirconia and yttria,
- the iron being present in an amount ranging from 1 weight percent to 20 weight percent, based on combined weight of the iron and the support;
- the yttria being present in an amount ranging from 1 mole percent to 95 mole percent, based on combined moles of yttria and zirconia, and
- the optional alkali metal, alkaline earth metal or combination thereof being present in an amount ranging from 0 mole percent to 6 mole percent, based on moles of the iron.
A catalyst for use in converting synthesis gas to olefins, prepared by a process comprising
- (1) dispersing an iron-containing compound and, optionally, an alkali metal, an alkaline earth metal, or a combination thereof, on a particulate catalyst support comprising zirconia and yttria;
- the amount of the iron-containing compound ranging from 1 weight percent to 20 weight percent, based on combined weight of the iron and the support;
- the amount of the optional alkali metal, alkaline earth metal, or combination thereof ranging from 0 mole percent to 6 mole percent, based on combined moles of the alkali metal, the alkaline earth metal, or combination thereof and the iron;
- and
- the amount of yttria ranging from 0.1 mole percent to 95 mole percent, based on combined moles of yttria and zirconia;
- (2) thermally at least partially decomposing the iron-containing compound to form a catalyst precursor composition comprising an iron oxide;
- (3) subjecting the catalyst precursor composition to at least partial carburization in a carbon monoxide-containing atmosphere to convert at least some of the iron oxides to iron carbides.
Dependencies are inferred from the claim text.