High pressure drop endothermic process
AssigneeMobil Oil Corporation
InventorMohsen N. Harandi
Life of this patent
Estimating the term…
Abstract
Aliphatic feeds are converted to olefins and/or aromatics in a multi pressure reactor system. A high pressure first stage reactor generates much or all of the hydrogen needed to reduce catalyst coking in lower pressure downstream reactors. High pressure operation protects catalyst stability in the first reactor, while produced hydrogen helps protect downstream catalyst. Low pressure downstream operation improves yields.
Claims20
A process for removing a designated amount of hydrogen from an aliphatic hydrocarbon feed comprising at least some saturated hydrocarbons in the C.sub.2 to C.sub.2 range by passing said feed over a weight of catalyst having catalytic activity for removing hydrogen from aliphatic hydrocarbons comprising:
- a. heating and vaporizing a high pressure liquid feed comprising said saturated hydrocarbons to produce a heated high pressure vapor stream having a designated temperature;
- b. charging to a first, high pressure, dehydrogenation reaction zone containing a portion of said catalyst said heated high pressure vapor and converting same in said high pressure dehydrogenation reaction zone to produce a first reaction zone effluent containing a limited amount of hydrogen;
- c. charging said first reaction zone effluent to a second reaction zone operating at a reduced pressure relative to said first reaction zone, and wherein the ratio of the absolute pressure in said second zone to said first zone is at least 1.35:1 and achieving in said second zone additional conversion of said first reaction zone effluent to produce said designated amount of hydrogen;
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- d. removing from said second reaction zone a reactor effluent stream of olefinic and/or aromatic product and produced hydrogen as a product of the process.
A process for dehydrogenating paraffins in a single bed reactor to form olefins comprising:
- a. heating and vaporizing a liquid feed comprising C.sub.2 to C.sub.2 saturated hydrocarbons and having a pressure of at least 25 psig to produce a heated vapor stream having a pressure of at least 25 psig;
- b. charging to a single reactor vessel containing one or more beds of a paraffin dehydrogenation catalyst said heated vapor having a pressure of at least 25 psig;
- c. depressuring and converting said vapor by passing said vapor through said catalyst in said reactor vessel, and wherein the absolute pressure of said vapor is reduced by at least 50 % by passage through said catalyst;
- d. removing from said reactor vessel an effluent stream of olefinic and/or aromatic product and produced hydrogen as a product of the process.
A process for dehydrocyclization of a feed containing C.sub.5 to C.sub.12 aliphatics in a multi reactor process comprising;
- a. heating and vaporizing a liquid feed containing C.sub.5 to C.sub.12 aliphatics and having a pressure of at least 100 psig to produce a heated vapor stream having a pressure above 100 psig;
- b. charging heated vapor to a first dehydrocyclization reactor operating at dehydrocyclization conditions including a pressure above 100 psig and containing a dehydrocyclization catalyst and converting a limited amount of said feed to produce a first reactor effluent containing produced hydrogen;
- c. charging said first reactor effluent to at least one downstream dehydrocyclization reactor operating at less than 1/2 the absolute pressure of said first reactor and containing a dehydrocyclization catalyst and converting in said downstream reactor additional amounts of said feed;
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- d. removing from said at least one downstream reactor a reactor effluent stream comprising aromatic products and produced hydrogen as a product of the process.
Dependencies are inferred from the claim text.