Method and system for purifying an ethylene-containing gas stream
AssigneeClariant GmbH
InventorsMingyong Sun, Steven A. Blankenship, Michael A. Urbancic, Richard Paul Zoldak
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Abstract
A two catalyst system is described having separate catalyst beds for the selective conversion of acetylene to ethylene which reduces the concentration of acetylene, dienes, O2, and NOx is disclosed. An ethylene containing gas stream, such as an off-gas stream from a refinery catalytic cracking unit used in the production of fuels and gas oils, is treated by first contacting the gas stream with a silver catalyst supported on a metal oxide and subsequently contacting the gas stream with a ruthenium catalyst supported on metal oxide. The two catalysts are contained within contiguous continuous reactors or reactor compartments.
Claims18
A method for the purification of an ethylene-containing gas stream which contains acetylenes, dienes, oxygen, and nitric oxide, the method comprising at least the steps of:
- a. contacting said ethylene-containing gas stream with a supported silver catalyst having a silver content of between about 0.5 and 10% by mass to produce a first processed ethylene-containing gas stream;
- and
- b. contacting said first catalytically processed gas stream with a supported ruthenium catalyst having a ruthenium content of between about 0.01 and 5% by mass to produce a second processed ethylene-containing gas stream containing less than about 1 ppm acetylene, less than about 1 ppm NOx, and less than about 1 ppm O2 with an ethylene loss of less than 2% relative to inlet ethylene
A continuous flow reactor system for processing a chemical feedstock having a first reactor stage possessing a first supported metal catalyst and a second reactor stage possessing a second supported metal catalyst wherein said first supported metal catalyst and said second supported metal catalyst are not identical and each function to process said chemical feedstock so as to accomplish said chemical processing, said first supported metal catalyst selected to beneficially process said chemical feedstock so as to clean up acetylenes, oxygen, and nitric oxide with low ethylene loss.
The method of extending the life and improving ethylene selectivity of a platinum series metal catalyst used in chemical processing comprising the step of contacting a chemical feedstock with a first supported metal catalyst selected to beneficially process said chemical feedstock so as to reduce the concentration of feedstock impurities detrimental to said platinum series metal catalyst.
Dependencies are inferred from the claim text.