阅读说明：本技术 一种混合碳四原料加氢精制的方法及其系统 (Method and system for hydrorefining mixed C-C raw material ) 是由 张登前 习远兵 李中亚 李善清 李洪宝 褚阳 田鹏程 于 2019-03-28 设计创作，主要内容包括：一种混合碳四原料加氢精制的方法及其系统。所涉及的方法为：混合碳四原料和惰性气体在第一反应器与硫醇醚化催化剂接触进行反应,其反应流出物分离后,所得低硫混合碳四物料在第二反应器与选择性加氢脱二烯催化剂接触进行脱二烯反应,得到低硫、低二烯烃混合碳四产品。本发明大大降低了选择性加氢脱二烯催化剂硫中毒风险,显著延长了选择性加氢脱二烯催化剂的使用周期,并且单烯收率高。(A hydrorefining method and system for mixed C-C raw material. The method comprises the following steps: the mixed C-C material and inert gas contact with a mercaptan etherification catalyst in a first reactor to react, after reaction effluent is separated, the obtained low-sulfur mixed C-C material contacts with a selective hydrogenation diene-removing catalyst in a second reactor to carry out diene-removing reaction, and a low-sulfur and low-diene mixed C-C product is obtained. The invention greatly reduces the risk of sulfur poisoning of the selective hydrogenation diene-removing catalyst, obviously prolongs the service cycle of the selective hydrogenation diene-removing catalyst and has high monoene yield.)

1. A method for hydrorefining a mixed C4 feedstock, comprising:

(1) the mixed C-IV raw material is in contact with a mercaptan etherification catalyst for reaction in a first reactor under the atmosphere of inert gas, and the obtained reaction effluent is separated to obtain a thioether and low-sulfur mixed C-IV material, wherein the mercaptan etherification catalyst is a catalyst which is loaded on an alumina carrier and contains at least one VIII group non-noble metal component and at least one VIB group metal component;

(2) the obtained low-sulfur mixed carbon four material, hydrogen and selective regulating gas enter a second reactor together, and are contacted with a selective hydrogenation diene-removing catalyst to carry out hydrogenation diene-removing reaction, and the reaction effluent of the second reactor is separated to obtain a low-sulfur low-diene mixed carbon four product, wherein the selective hydrogenation diene-removing catalyst is a noble metal catalyst; the selective hydrodedienization catalyst includes at least one group VIII noble metal component and optionally a group IB metal component.

2. The process according to claim 1, characterized in that in the mercaptan etherification catalyst in step (1), the non-noble group VIII metal is selected from cobalt and/or nickel, the group VIB metal component is selected from molybdenum and/or tungsten; calculated by oxides and taking a mercaptan etherification catalyst as a reference, the mass fraction of the VIII group non-noble metal component is 1-40%, and the mass fraction of the VIB group metal component is 0.1-10%.

3. The method according to claim 2, characterized in that the non-noble group VIII metal component in the mercaptan etherification catalyst is nickel, the group VIB metal component is molybdenum, and the mass fraction of nickel is 3-25% and the mass fraction of molybdenum is 0.5-4.5% in terms of oxides and based on the mercaptan etherification catalyst.

4. The process of claim 1 wherein the selective hydrodediene catalyst of step (2) comprises a support comprising alumina and/or silica-alumina and a hydrogenation-active metal component comprising at least one group VIII noble metal component selected from palladium and/or platinum and optionally a group IB metal component.

5. The process of claim 4, wherein the mass fraction of palladium and/or platinum is 0.05 to 1% and the mass fraction of the group IB metal component is 0 to 0.5%, calculated as the oxide and based on the selective hydrodediene catalyst.

6. The method according to claim 1, wherein the mixed C-IV raw material is a C-IV material or a C-III-C-IV mixed material obtained by a catalytic cracking, atmospheric and vacuum distillation, coking and hydrocracking device, the volume fraction of butadiene in the mixed C-IV raw material is 0.005-1%, the sulfur content is 10-500 μ g/g, and the mercaptan sulfur accounts for 50-98% of the mass of the sulfur-containing compound.

7. The method according to claim 1, wherein the inert gas in step (1) is selected from one or more of nitrogen, helium and argon; the volume ratio of the inert gas to the mixed C-C raw material in a standard state is 1-50: 1, and preferably 2-30: 1.

8. The method according to claim 1, wherein the reaction atmosphere of the first reactor in the step (1) further contains hydrogen; the volume ratio of the hydrogen to the mixed carbon four raw material in the standard state is 1-100: 1, and preferably 2-60: 1.

9. The method according to claim 1, wherein the reaction conditions of the first reactor in step (1) are: the pressure is 0.3-4.0 MPa, the reaction temperature is 30-250 ℃, and the volume space velocity is 1.0-20.0 h^-1；

The reaction conditions of the second reactor in the step (2) are as follows: hydrogen partial pressure of 0.3-4.0 MPa, reaction temperature of 30-150 ℃ and volume space velocity of 1.0-20.0 h^-1And the molar ratio of the hydro-diene is 0.5-50.

10. The process according to claim 1 or 9, wherein the reaction conditions of the first reactor in step (1) are: the pressure is 0.5-2.5 MPa, the reaction temperature is 60-200 ℃, and the volume space velocity is 2.0-10.0 h^-1；

The reaction conditions of the second reactor in the step (2) are as follows: hydrogen partial pressure of 0.5-3.0 MPa, reaction temperature of 40-130 ℃ and volume space velocity of 2.0-10 h^-1And the molar ratio of the hydro-diene is 1.0-10.

11. The method according to claim 1, wherein the sulfur content of the low-sulfur mixed carbon-four material in the step (1) is 0-10 μ g/g.

12. The method of claim 1, wherein the selective conditioning gas of step (2) is selected from the group consisting of CO and CO₂、NO、H₂One or more of S; based on the total volume of the second reactor feed mixture, the volume fraction of the selective tuning gas is: 0.001 to 10 percent.

13. The process of claim 1, wherein the volume fraction of diolefins in the low sulfur, low diolefin mixed carbon four product of step (2) is 0 to 0.005%, preferably 0 to 0.003%.

14. A system for hydrorefining mixed C-C raw material comprises a first reactor, a second reactor, a first separation area and a second separation area;

a mixed C4 raw material pipeline and an inert gas pipeline are communicated with an inlet of a first reactor, a mercaptan etherification catalyst is filled in the first reactor, and the mercaptan etherification catalyst is a catalyst which is loaded on an alumina carrier and contains at least one VIII group non-noble metal component and at least one VIB group metal component; the outlet of the first reactor is communicated with the inlet of the first separation area, and the first separation area is provided with a high-boiling-point thioether outlet and a low-sulfur mixed carbon four material outlet; the outlet of the low-sulfur mixed carbon-four material is communicated with the inlet of a second reactor, a hydrogen pipeline and a selective regulation and control gas pipeline are communicated with the inlet of the second reactor, and a selective hydrodediene catalyst is filled in the second reactor and comprises at least one VIII group noble metal and optional IB group metal; the outlet of the second reactor is communicated with the inlet of the second separation zone, and the second separation zone is provided with a low-sulfur and low-diene mixed carbon four product outlet.

15. The system of claim 14, wherein the mercaptan etherification catalyst comprises a group VIII non-noble metal selected from cobalt and/or nickel, a group VIB metal component selected from molybdenum and/or tungsten; calculated by oxides and taking a mercaptan etherification catalyst as a reference, the mass fraction of the VIII group non-noble metal component is 1-40%, and the mass fraction of the VIB group metal component is 0.1-10%.

16. The system according to claim 15, wherein the non-noble group VIII metal component of the mercaptan etherification catalyst is nickel, the group VIB metal component of the mercaptan etherification catalyst is molybdenum, and the mass fraction of nickel is 3 to 25% and the mass fraction of molybdenum is 0.5 to 4.5% in terms of oxides and based on the mercaptan etherification catalyst.

17. The system of claim 14 wherein the selective hydrodediene catalyst comprises a support and a hydrogenation-active metal component, the support being alumina and/or silica-alumina, the hydrogenation-active metal component comprising at least one group VIII noble metal component and optionally a group IB metal component, wherein the group VIII noble metal component is selected from palladium and/or platinum.

18. The system of claim 17, wherein the mass fraction of palladium and/or platinum is 0.05 to 1% and the mass fraction of the group IB metal component is 0 to 0.5%, calculated as the oxide and based on the selective hydrodediene catalyst.

Technical Field

The invention provides a method and a system for producing a superposed raw material by hydrorefining a mixed carbon four raw material.

Background

Along with the establishment and implementation of the national fifth and sixth standards, the requirement of high-octane clean gasoline components is increasing day by day, and meanwhile, along with the large-scale popularization of domestic ethanol gasoline, the high-octane component methyl tert-butyl ether (MTBE) widely used for blending gasoline cannot be added into the ethanol gasoline, so that a large number of MTBE substitution technologies are developed at home and abroad in the face of the deficiency of the high-octane component of the clean gasoline. One of these is the polymerization of isobutene. The carbon tetraolefin polymerization technology can replace the MTBE technology, fully utilizes the refinery mixed carbon four raw material, and simultaneously, the polymerization product is a clean gasoline component with high octane value.

The raw material of the superposition technology generally adopts mixed carbon four components produced by catalytic cracking and other processes, and the mixed carbon four raw material generally contains 0.1 to 1.2 percent of butadiene. In the case of the carbon tetraolefin polymerization technique, butadiene can deactivate the polymerization catalyst by rapid carbon deposition. The best way to solve this problem is to remove butadiene from the feedstock by selective hydrogenation. The raw material in the mixed carbon four is removed by adopting a hydrogenation method, and a noble metal catalyst and a liquid phase hydrogenation method, such as a supported Pd catalyst, are usually adopted. The prior art makes appropriate improvements to Pd catalysts to increase the activity and selectivity of the catalyst.

In the selective hydrogenation and diene removal process of the mixed C-C four raw material, the raw material contains a certain amount of sulfur (10-200 mu g/g), and sulfur-containing compounds can poison the selective hydrogenation and diene removal catalyst, so that the activity of the selective hydrogenation and diene removal catalyst is rapidly reduced, and the operation cycle of the catalyst is seriously influenced. And moreover, sulfides in the mixed C4 can enter the superimposed product, so that the sulfur content of gasoline blending components can not meet the requirements of national fifth and sixth standards.

At present, the method for removing sulfides in mixed C4 is mainly to carry out crude desulfurization by solid alkali and then remove various sulfides contained in the crude desulfurization by using a hydrolytic agent or an adsorbent at one time.

CN101249366A discloses a fine desulfurization method, which comprises the steps of firstly, carrying out coarse desulfurization on four carbon components in a refinery by using solid alkali, and then contacting with a carbonyl sulfide adsorbent to adsorb and remove most of carbonyl sulfide and mercaptan in the carbonyl sulfide; then contacting with a fine desulfurization adsorbent to adsorb and remove the residual sulfur. After the refinery carbon four components are subjected to fine desulfurization treatment by the method provided by the invention, the total sulfur content can be reduced to 1mg/m³The following.

CN103102987A discloses a fine desulfurization method for a carbon four-fraction, which comprises the steps of carrying out amine washing desulfurization and alkali washing on a liquefied petroleum gas which is a byproduct of a catalytic cracking device, a catalytic cracking device and the like to remove mercaptan, separating three carbon components in the liquefied petroleum gas by a gas separation device, separating a mixed carbon four-fraction from the gas separation device through the top of a light component removal tower to obtain a component rich in isobutane and trace carbonyl sulfide COS, and feeding the residual fraction into a heavy component removal tower; separating refined mixed carbon four fraction rich in butene component at the top of the de-heavy tower, wherein the sulfur content of the component is less than 3mg/m³。

Patent TW201011100A discloses a process for removing mercaptans from a gaseous mixture, in which a gaseous mixture comprising hydrocarbons and mercaptans is first fed to a reactor, etherified over a catalyst comprising palladium and silver, and after etherification the reactor product mixture is fractionated to separate the lower boiling hydrocarbons from the thioethers for the purpose of desulfurization.

Disclosure of Invention

The invention aims to provide a method and a system for hydrorefining a mixed C-C four raw material, which are used for solving the problems of easy inactivation, poor selectivity and the like of a selective hydrogenation diene-removing catalyst in the prior art.

The invention provides a method for hydrorefining mixed C-C raw material, which comprises the following steps:

(1) the mixed C-IV raw material is in contact with a mercaptan etherification catalyst for reaction in a first reactor under the atmosphere of inert gas, and the obtained reaction effluent is separated to obtain a thioether and low-sulfur mixed C-IV material, wherein the mercaptan etherification catalyst is a catalyst which is loaded on an alumina carrier and contains at least one VIII group non-noble metal component and at least one VIB group metal component;

(2) the obtained low-sulfur mixed carbon four material, hydrogen and selective regulating gas enter a second reactor together, and are contacted with a selective hydrogenation diene-removing catalyst to carry out hydrogenation diene-removing reaction, and the reaction effluent of the second reactor is separated to obtain a low-sulfur low-diene mixed carbon four product, wherein the selective hydrogenation diene-removing catalyst is a noble metal catalyst; the selective hydrodedienization catalyst includes at least one group VIII noble metal component and optionally a group IB metal component.

In the invention, the mixed C-C raw material is a C-C material or a C-C mixed material obtained by a catalytic cracking, atmospheric and vacuum distillation, coking and hydrocracking device, the volume fraction of butadiene in the mixed C-C raw material is 0.005-1%, the sulfur content is 10-500 mu g/g, and the mercaptan sulfur accounts for 50-98% based on the mass of a sulfur-containing compound.

In the invention, the sulfur-containing compounds in the mixed C-C raw material mainly exist in the form of mercaptan, and in the first reactor, the mercaptan and the olefin are subjected to an addition reaction under the action of a mercaptan etherification catalyst to generate the high-boiling-point thioether.

In a preferred case, in the mercaptan etherification catalyst, the non-noble group VIII metal component is selected from cobalt and/or nickel, and the group VIB metal component is selected from molybdenum and/or tungsten; calculated by oxides and taking a mercaptan etherification catalyst as a reference, the mass fraction of the VIII group non-noble metal component is 1-40%, and the mass fraction of the VIB group metal component is 0.1-10%.

Preferably, the VIII group non-noble metal component in the mercaptan etherification catalyst is nickel, the VIB group metal component is molybdenum, the mass fraction of the nickel is 3-25% and the mass fraction of the molybdenum is 0.5-4.5% in terms of oxides and on the basis of the mercaptan etherification catalyst.

In one preferred embodiment of the present invention, the reaction atmosphere in the first reactor in step (1) does not contain hydrogen, and the mixed C-C feedstock is contacted with a mercaptan etherification catalyst in an inert gas atmosphere to carry out mercaptan etherification reaction, so that most of mercaptan and diene react to form high-boiling thioether.

In a preferable case, the inert gas in the step (1) is selected from one or more of nitrogen, helium and argon; the volume ratio of the inert gas to the mixed C-C raw material in a standard state is 1-50: 1, and more preferably 2-30: 1.

In another preferred embodiment of the present invention, the reaction atmosphere of the first reactor in step (1) further contains hydrogen; the method comprises the steps of enabling inert gas and hydrogen to exist in a reaction atmosphere at the same time, wherein the volume ratio of the hydrogen to the mixed carbon four raw material in a standard state is 1-100: 1, and preferably 2-60: 1.

In a preferred aspect, the reaction conditions of the first reactor in step (1) are: the pressure is 0.3-4.0 MPa, the reaction temperature is 30-250 ℃, and the volume space velocity is 1.0-20.0 h^-1(ii) a More preferred reaction conditions are: the pressure is 0.5-2.5 MPa, the reaction temperature is 60-200 ℃, and the volume space velocity is 2.0-10.0 h^-1。

And separating the reaction effluent of the first reactor to obtain the four materials of the thioether and the low-sulfur mixed carbon. Preferably, the separation is carried out by adopting a fractionation method, the upper part of the fractionating tower obtains low-sulfur mixed C-C material, and the lower part of the fractionating tower obtains thioether.

Preferably, the sulfur content of the low-sulfur mixed carbon four material is 0-10 mu g/g, and more preferably 0-6 mu g/g.

In the step (2), the low-sulfur mixed carbon four material, hydrogen and selective control gas enter a second reactor together, and are contacted with a selective hydrogenation and diene removal catalyst to perform a selective hydrogenation and diene removal reaction.

Preferably, the selective control gas is selected from CO and CO₂、NO、H₂One or more of S; based on the total volume of the second reactor feed mixture, the volume fraction of the selective tuning gas is: 0.001 to 10 percent. The feeding mixture of the second reactor is the mixture of low-sulfur mixed carbon four material, hydrogen and selective regulating gas entering the second reactor.

In a preferred case, the reaction conditions of the second reactor are: hydrogen componentThe pressure is 0.3-4.0 MPa, the reaction temperature is 30-150 ℃, and the volume space velocity is 1.0-20.0 h^-1And the molar ratio of the hydro-diene is 0.5-50.

More preferably: hydrogen partial pressure of 0.5-3.0 MPa, reaction temperature of 40-130 ℃ and volume space velocity of 2.0-10 h^-1And the molar ratio of the hydro-diene is 1.0-10.

In a preferred case, the selective hydrodedienization catalyst comprises a support, which is alumina and/or silica-alumina, and a hydrogenation-active metal component comprising at least one group VIII noble metal component, selected from palladium and/or platinum, and optionally a group IB metal component. In the present invention, the optional group IB metal component means that the group IB metal component is an optional component, and may or may not be present. The group IB metal component is selected from one or more of copper, silver and gold.

Further preferably, the mass fraction of palladium and/or platinum is 0.05 to 1% and the mass fraction of the group IB metal component is 0 to 0.5%, calculated on the basis of the oxide and based on the selective hydrogenation and diene removal catalyst.

In the present invention, the method for introducing the hydrogenation active metal to the carrier in the selective hydrogenation and diene removal catalyst is preferably an impregnation method, and the impregnation method is a conventional method, such as pore saturation impregnation, excess liquid impregnation, spray impregnation, and the like. Wherein, one or more of the VIII group noble metal component and the IB group metal component can be independently introduced, or can be introduced two by two or three simultaneously. When the impregnation is a stepwise impregnation, there is no limitation on the order in which the impregnation solution impregnates the support. Although not required, a drying step is preferably included after each impregnation. The drying conditions include: the drying temperature is 100-210 ℃, preferably 120-190 ℃, and the drying time is 1-6 hours, preferably 2-4 hours.

And separating the reaction effluent of the second reactor to obtain a low-sulfur and low-diene mixed C4 product. Preferably, the volume fraction of the diolefins in the low-sulfur and low-diolefin mixed C4 product is 0-0.005%, and more preferably 0-0.003%.

The invention also provides a system for hydrorefining the mixed C-C raw material, which comprises a first reactor, a second reactor, a first separation area and a second separation area;

a mixed C4 raw material pipeline and an inert gas pipeline are communicated with an inlet of a first reactor, a mercaptan etherification catalyst is filled in the first reactor, and the mercaptan etherification catalyst is a catalyst which is loaded on an alumina carrier and contains at least one VIII group non-noble metal component and at least one VIB group metal component; the outlet of the first reactor is communicated with the inlet of the first separation area, and the first separation area is provided with a high-boiling-point thioether outlet and a low-sulfur mixed carbon four material outlet; the outlet of the low-sulfur mixed carbon-four material is communicated with the inlet of a second reactor, a hydrogen pipeline and a selective regulation and control gas pipeline are communicated with the inlet of the second reactor, and a selective hydrodediene catalyst is filled in the second reactor and comprises at least one VIII group noble metal and optional IB group metal; the outlet of the second reactor is communicated with the inlet of the second separation zone, and the second separation zone is provided with a low-sulfur and low-diene mixed carbon four product outlet.

In a preferred case, in the mercaptan etherification catalyst, the non-noble group VIII metal is selected from cobalt and/or nickel, and the group VIB metal component is selected from molybdenum and/or tungsten; calculated by oxides and taking a mercaptan etherification catalyst as a reference, the mass fraction of the VIII group non-noble metal component is 1-40%, and the mass fraction of the VIB group metal component is 0.1-10%.

Preferably, the VIII group non-noble metal component in the mercaptan etherification catalyst is nickel, the VIB group metal component is molybdenum, the mass fraction of the nickel is 3-25% and the mass fraction of the molybdenum is 0.5-4.5% in terms of oxides and on the basis of the mercaptan etherification catalyst.

In a preferred case, the selective hydrodediene catalyst comprises a carrier and a hydrogenation active metal component, wherein the carrier is alumina and/or silica-alumina, and the hydrogenation active metal component comprises at least one group VIII noble metal component and an optional group IB metal component, wherein the group VIII noble metal component is selected from palladium and/or platinum, and the group IB metal component is selected from one or more of copper, silver and gold.

Further preferably, the mass fraction of palladium and/or platinum is 0.05 to 1% and the mass fraction of the group IB metal component is 0 to 0.5%, calculated on the basis of the oxide and based on the selective hydrogenation and diene removal catalyst.

The method and the system for hydrofining the mixed carbon four raw material can process the mixed carbon four raw material with high butadiene content and high sulfur content to produce a superposed raw material with the sulfur content of less than 10 mu g/g and the diene content of less than 0.005 volume percent. Compared with the prior art, the method has the advantages of good selectivity, high mono-olefin yield, long system running period, good environmental protection and the like.

Drawings

FIG. 1 is a schematic diagram of a mixed carbon four feedstock hydrofinishing system provided by the present invention.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The present invention will be further described with reference to the drawings, but the present invention is not limited thereto.

As shown in FIG. 1, the system for producing a superimposed feedstock by hydrofining a mixed carbon four feedstock provided by the present invention comprises a first reactor 11, a second reactor 12, a first separation zone 5 and a second separation zone 13.

A mixed carbon four raw material pipeline 1 and an inert gas pipeline 2 are communicated with a general pipeline 3 connected with the inlet of a first reactor 11, and a mercaptan etherification catalyst is filled in the first reactor; the outlet of the first reactor is communicated with the inlet of a first separation zone 5 through a pipeline 4, the first separation zone 5 is a fractionating tower, the bottom of the fractionating tower is provided with a high-boiling-point thioether outlet and is connected with a pipeline 6, the top of the fractionating tower is provided with an inert gas outlet and is connected with a pipeline 7, the outlet of a low-sulfur mixed carbon four-material of the fractionating tower is connected with the inlet of a second reactor 12 through a pipeline 8, hydrogen and a selective regulation and control gas pipeline 9 are communicated with the inlet of the second reactor 12, and a selective hydrogenation and diene removal catalyst is filled in the second reactor and comprises at least one VIII group noble metal and optional IB group metal; the outlet 10 of the second reactor is communicated with the inlet of a second separation zone 13 which is provided with a low sulfur and low diene mixed carbon four product outlet and is communicated with a pipeline 14.

The following examples further illustrate the process of the present invention but are not intended to limit the invention thereto.