US 11,253,816 B2 · Direct oxidation of hydrogen sulfide in a hydroprocessing recycle gas stream with hydrogen purification

Abstract

A process and system for treating a hydroprocessing unit effluent gas stream for recycling includes introducing the effluent gas stream into a hydrogen purification zone and recovering a hydrogen-rich gas stream and a liquid stream containing a mixture that includes C1 to C4 hydrocarbons and H2S which is then mixed with an oxidant and fed to an oxidation unit containing catalyst for conversion of the H2S to elemental sulfur vapors that is separated for recovery of the elemental sulfur, and recovering a sweetened mixture that includes C1 to C4 hydrocarbons. Alternatively, the hydroprocessing unit effluent gas stream containing H2S is cooled, contacted with a solvent to absorb the C1 to C4 hydrocarbons and H2S, with the hydrogen-rich stream being recovered for recycling to the hydroprocessing unit, and the rich liquid solvent being flashed to produce a lean solvent stream for recycling to the adsorption zone and a mixed gas stream that includes the C1 to C4 hydrocarbons and H2S that is passed to an oxidation zone and is reacted with an oxidant in the presence of a catalyst to complete the process as described above for the recovery of elemental sulfur and a mixture that includes the sweetened C1 to C4 hydrocarbons.

Claims14

Dependent claims

An integrated process for the treatment of a hydrocarbon hydrocracking unit recycle gas stream, the process comprising:

a. mixing a sulfur-containing heavy hydrocarbon liquid feedstock with hydrogen gas to produce a combined feedstream and introducing the combined feedstream into a hydrocracking unit;
b. hydrocracking the combined feedstream to produce a hydrocracking unit effluent stream;
c. passing the effluent stream to a gas/liquid separator and removing a liquid effluent stream and a gaseous effluent stream from the separator;
d. introducing the gaseous effluent stream into a hydrogen purification unit to produce a hydrogen-rich gas stream and a hydrogen-lean stream consisting essentially of a mixture of C1 to C4 hydrocarbons and H2S;
e. mixing the hydrogen-lean stream consisting essentially of the mixture of C1 to C4 hydrocarbons and H2S with an oxidant to produce an oxidation unit feedstream;
f. contacting the oxidation unit feedstream in a catalytic oxidation unit with a catalyst, wherein the catalyst is MgCr2O4 or Cu—Zn on an alumina support, to convert substantially all of the H2S to elemental sulfur and to produce an oxidation unit effluent stream comprising a sweetened mixture of C1 to C4 hydrocarbons and elemental sulfur vapors;
g. condensing the sulfur vapors and recovering the elemental sulfur from the oxidation unit effluent stream;
and
h. recovering the sweetened mixture of C1 to C4 hydrocarbons from the oxidation unit.

6 more elements

An integrated process for the treatment of a hydrocracking unit hydrocarbon recycle gas stream, the process comprising:

a. mixing a sulfur-containing heavy hydrocarbon liquid feedstock with hydrogen gas to produce a combined feedstream and introducing the combined feedstream into a hydrocracking unit;
b. hydrocracking the combined feedstream to produce a hydrocracking unit effluent stream;
c. separating the hydrocracking unit effluent stream in a gas/liquid separator into a hydrocracking unit effluent liquid stream and a hydrocracking unit effluent gas stream;
cooling the hydrocracking unit effluent gas stream and recovering a cooled hydrocracking unit effluent gas stream;
e. introducing the cooled hydrocracking unit effluent gas stream and a liquid solvent stream into an absorption zone to absorb a mixture comprising C1 to C4 hydrocarbons and H2S and produce a hydrogen-rich gas stream and a rich liquid solvent stream comprising a mixture of C1 to C4 hydrocarbons and H2S;
f. recovering the hydrogen-rich gas stream for use as a recycle hydrogen gas stream;
g. recovering and flashing the rich liquid solvent stream comprising the mixture of C1 to C4 hydrocarbons and H2S in at least one flashing zone to produce a lean liquid solvent stream and a second stream consisting essentially of a mixture of C1 to C4 hydrocarbons and H2S;
h. mixing the second stream consisting essentially of the mixture of C1 to C4 hydrocarbons and H2S with an oxidant to produce an oxidation unit feedstream;
i. oxidizing the oxidation unit feedstream in an oxidation unit in the presence of a catalyst, wherein the catalyst is MgCr2O4 on an alumina support or Cu—Zn on an alumina support, to convert substantially all of the H2S to elemental sulfur vapors and separating the elemental sulfur vapors from the hydrocarbon mixture consisting essentially of sweetened C1 to C4 hydrocarbons;
j. recovering elemental sulfur vapors from the oxidation unit;
and
k. recovering the mixture consisting essentially of sweetened C1 to C4 hydrocarbons from the oxidation unit.

9 more elements

Dependencies are inferred from the claim text.

Direct oxidation of hydrogen sulfide in a hydroprocessing recycle gas stream with hydrogen purification

Life of this patent

Direct oxidation of hydrogen sulfide in a hydroprocessing recycle gas stream with hydrogen purification

Life of this patent

Abstract

Claims14