Coking reduction in cracking reactors
AssigneeArkema France
InventorsFrancis Humblot, Claude Brun, Harry M. Woerde, Paul F. Van Den Oosterkamp
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Abstract
The invention concerns a method for reducing coking on the metal walls of a reactor cracking hydrocarbons or other organic compounds and on the metal walls of a heat exchanger placed downstream of the cracking reactor, whereby the metal surfaces coming into contact with the organic substance to be cracked are pre-treated with a water vapor stream containing at least silicon and at least a sulphur compound.
Claims25
A process for reducing coking on the metal walls of a cracking reactor and a heat exchanger placed subsequent to the cracking reactor for cracking of a feedstock of hydrocarbons or of other organic compounds comprising:
- pretreating the metal walls coming into contact with the organic compounds to be cracked with a stream of steam with at least one non-sulphur-containing silicon compound which is hexamethyldisiloxane and at least one non-silicon-containing sulphur compound which is dimethyldisulfide at a temperature between 300 and 1100° C. for 0.5 to 12 hours, wherein the Si:S atomic ratio is between 2:1 and 1:2 and the concentration of silicon is less than 500 ppm;
- cracking the feedstock hydrocarbons or other organic compounds in the cracking reactor and heat exchanger;
- and
- decoking the cracking reactor and heat exchanger with a mixture of air and steam.
A process for reducing coking on metal walls of a cracking reactor and a heat exchanger placed subsequent to the cracking reactor for the cracking of hydrocarbons or other organic compounds comprising;
- pretreating the metal walls coming into contact with the organic compounds to be cracked with a stream of steam having at least one non-sulphur-containing silicon compound and at least one non-silicon-containing sulphur compound at a temperature between 300 and 1100° C. for 0.5 to 12 hours, such that the at least one non-silicon containing sulphur compound is carbon disulphide or a compound of formula R1—Sx—R2 in which R1 and R2, which are identical or different, each are representative of a hydrogen atom or hydrocarbonaceous group, and x is a number equal to or greater than 1, such that an inhibition of coke percentage on the metal walls of the cracking reactor and the heat exchanger is 36 to 66%;
- cracking the feedstock hydrocarbons or other organic compounds in the cracking reactor and heat exchanger;
- and
- decoking the cracking reactor and heat exchanger with a mixture of air and steam.
Dependencies are inferred from the claim text.