阅读说明：本技术 一种固体催化剂组合装填的芳烃中脱除微量烯烃的方法 (Method for removing trace olefin from aromatic hydrocarbon filled with solid catalyst combination ) 是由 李水荣 朱志荣 孙晓明 赵国庆 潘茂华 于 2020-04-03 设计创作，主要内容包括：本发明涉及石化领域,公开了一种固体催化剂组合装填的芳烃中脱除微量烯烃的方法,包括以下步骤：将芳烃原料置于脱烯烃反应器中,在温度和压力条件下,自上而下分别通过两段反应区,两段反应区中按照芳烃原料的流动方向分别装填催化剂A和催化剂B,其中,催化剂A为改性白土吸附剂,催化剂B为改性Y分子筛催化剂；芳烃原料通过化学吸附与催化反应后脱除烯烃。本发明方法充分利用两种不同催化剂的自身优势,通过发挥协同作用,提高了整个芳烃脱除烯烃体系的活性与效率,吸附与反应的组合方法降低了反应产物的溴指数,并大幅延长了催化剂的寿命。(The invention relates to the field of petrifaction, and discloses a method for removing trace olefin from aromatic hydrocarbon filled with a solid catalyst combination, which comprises the following steps: placing an aromatic hydrocarbon raw material in a de-olefin reactor, and respectively passing through two reaction zones from top to bottom under the conditions of temperature and pressure, wherein the two reaction zones are respectively filled with a catalyst A and a catalyst B according to the flowing direction of the aromatic hydrocarbon raw material, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst; the olefin is removed from the aromatic hydrocarbon raw material after chemical adsorption and catalytic reaction. The method of the invention fully utilizes the advantages of two different catalysts, improves the activity and efficiency of the whole aromatic hydrocarbon olefin removal system by exerting the synergistic effect, reduces the bromine index of the reaction product by the combined method of adsorption and reaction, and greatly prolongs the service life of the catalyst.)

1. A method for removing trace olefin from aromatic hydrocarbon loaded with a solid catalyst combination is characterized by comprising the following steps: placing an aromatic hydrocarbon raw material in a de-olefin reactor, and respectively passing through two reaction zones from top to bottom under the conditions of temperature and pressure, wherein the two reaction zones are respectively filled with a catalyst A and a catalyst B according to the flowing direction of the aromatic hydrocarbon raw material, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst; the olefin is removed from the aromatic hydrocarbon raw material after chemical adsorption and catalytic reaction.

2. The method of claim 1, wherein:

the modified clay adsorbent is acidified activated clay, wherein the acidification is carried out by mixing one of hydrochloric acid, sulfuric acid and nitric acid with phosphoric acid according to a mass ratio of 0.8-1.2:1 to obtain mixed acid, and the total concentration of the mixed acid aqueous solution is 1.0-12.0 wt%; and/or

The modified Y molecular sieve catalyst is a Y molecular sieve modified by treatment of an acid aqueous solution, the acid aqueous solution is a mixed acid obtained by mixing hydrochloric acid or phosphoric acid and one of citric acid, acetic acid and oxalic acid according to a mass ratio of 1:1.5-2.5, and the total concentration of the mixed acid aqueous solution is 5.0-10.0 wt%.

3. The method of claim 1 or 2, wherein: the filling mass ratio of the catalyst A to the catalyst B is 0.1-8: 1.

4. The method of claim 1, wherein: and an inert region for isolation is filled between the catalyst A and the catalyst B, and the filling thickness of the inert region is not less than that of the catalyst A and the catalyst B.

5. The method of claim 4, wherein: the filler of the inert zone is inert glass beads and/or ceramic rings.

6. The method of claim 1, wherein: the temperature is 120-200 ℃, the pressure is 0.1-2.0 MPa, and the mass space velocity is 0.05-2.0 h^-1。

7. The method of claim 1, wherein: and after the catalyst A and the catalyst B are filled, inert gas is introduced for purging before reaction.

8. The method of claim 7, wherein:

the inert gas is one of nitrogen, helium and argon; and/or

The purging temperature is 150-450 ℃, the purging flow rate of the inert gas is 80-200 mL/min, and the purging time is 0.5-5 h.

9. The method of claim 1, wherein: the aromatic hydrocarbon raw material is crude aromatic oil or a carbon eight aromatic hydrocarbon isomerization product generated by a reforming device.

10. A combined filling solid catalyst for removing trace olefin from aromatic hydrocarbon is characterized in that: the catalyst comprises a catalyst A and a catalyst B, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst.

Technical Field

The invention relates to the field of petrifaction, in particular to a method for removing trace olefin from aromatic hydrocarbon filled with a solid catalyst in a combined manner.

Background

With rapid progress of science and technology and continuous improvement of production and living demands, the production and demand of synthetic materials such as plastics, chemical fibers, rubber and the like, additives, organic solvents, medicines, pesticides, coatings, dyes, various organic synthetic intermediates and the like, which take aromatic hydrocarbons as raw materials, are rapidly increased. Particularly, the aromatic hydrocarbon product market has been expanding since the 21 st century, and the productivity and yield of global aromatic hydrocarbon plants have been continuously increasing. At present, the main products of global aromatics are light aromatics such as benzene, toluene, xylene, and the like. In recent years, the polyester industry in China develops rapidly, and the development of the upstream aromatic hydrocarbon industry is promoted continuously.

The traditional aromatic hydrocarbon production technology comprises a disproportionation and transalkylation technology, a carbon-eight aromatic hydrocarbon isomerization technology, a PX separation technology and the like, and new technologies such as a toluene-methanol alkylation technology, a light hydrocarbon aromatization technology, a catalytic cracking light cycle oil aromatic hydrocarbon conversion technology and the like are continuously upgraded and updated in a way of adapting to the development of an aromatic hydrocarbon market. However, a certain amount of olefin impurities cannot be avoided in the produced aromatic hydrocarbon product, and the existence of the olefin impurities not only affects the purity and specification of the aromatic hydrocarbon product, but also the olefin with active properties is easy to form colloid, so that the quality of the aromatic hydrocarbon product is unqualified, and some subsequent process procedures are affected, and further processing and utilization of the aromatic hydrocarbon are affected.

At present, the production process for removing trace olefin impurities in aromatic hydrocarbon by oil refineries at home and abroad mainly comprises hydrofining and clay refining, wherein the clay refining method is most commonly used. The clay refining process is to contact clay with olefin-containing arene and utilize the relatively high porosity of clay to adsorb and eliminate olefin. However, the clay has small specific surface area, is easy to adsorb and saturate, has short service cycle and needs to be replaced frequently. Moreover, because of the irreproducibility of the clay structure, the clay is generally treated by landfill, which causes serious pollution to the environment. In addition, the removal and reinstallation of clay may have some effect on production. Compared with clay, the molecular sieve has higher specific surface area, can obtain acidity through treatment such as ion exchange and the like, has better activity in the reaction of removing olefin from aromatic hydrocarbon, has longer service life, has the characteristic of regeneration, and is beneficial to environmental protection besides reducing the replacement frequency of the catalyst. After the composition is combined with the argil, the composition has remarkable synergistic effect.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for removing trace olefin from aromatic hydrocarbon filled with a solid catalyst in a combined manner.

The specific technical scheme of the invention is as follows: a method for removing trace olefin from aromatic hydrocarbon loaded with a solid catalyst combination comprises the following steps: placing an aromatic hydrocarbon raw material in a de-olefin reactor, and respectively passing through two reaction zones from top to bottom under the conditions of temperature and pressure, wherein the two reaction zones are respectively filled with a catalyst A and a catalyst B according to the flowing direction of the aromatic hydrocarbon raw material, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst; the olefin is removed from the aromatic hydrocarbon raw material after chemical adsorption and catalytic reaction.

The invention initiatively applies the combination of the activated clay and the Y molecular sieve to the removal of trace olefin in aromatic hydrocarbon, the two can mutually promote to generate a synergistic action, and the synergistic action and the mechanism are as follows: the two pore channel structures and surface properties of the catalyst A and the catalyst B are different. The trace aromatic hydrocarbon in the reaction raw material is of various types, so the catalyst A and the catalyst B play a role in respectively removing part of the trace aromatic hydrocarbon. In addition, some minor amounts of olefins may react on catalyst A and then further react on catalyst B to complete the removal. The catalyst A and the catalyst B are matched with each other and selectively play roles, but are mutually promoted and cooperated, so that the whole catalyst unit has very good catalyst activity and stability.

The process of the invention is carried out in a fixed bed continuous flow reactor, the process of which is briefly described below: and putting the required amount of catalyst into a constant temperature area of the reactor, filling the lower part of the catalyst with glass beads or quartz sand, and putting a small amount of glass beads or quartz sand into the upper part of the catalyst. Under the set temperature and pressure, the arene material is pumped into the reactor via the preheater and the catalyst bed layer for catalytic reaction, and the reaction product is analyzed in the bromine index analyzer to determine the bromine index of the product.

Preferably, the modified clay adsorbent is acidified activated clay, the acidification is performed by using mixed acid obtained by mixing one of inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid with phosphoric acid according to the mass ratio of 0.8-1.2:1, and the total concentration of the mixed acid aqueous solution is 1.0-12.0 wt%.

Preferably, the modified Y molecular sieve catalyst is a Y molecular sieve modified by treatment with an acid aqueous solution, the acid aqueous solution is a mixed acid obtained by mixing hydrochloric acid or phosphoric acid and one of organic acids such as citric acid, acetic acid and oxalic acid according to a mass ratio of 1:1.5-2.5, and the total concentration of the mixed acid aqueous solution is 5.0-10.0 wt%.

Preferably, the loading mass ratio of the catalyst A to the catalyst B is 0.1-8: 1.

Preferably, an inert region for isolation is filled between the catalyst a and the catalyst B, and the filling thickness of the inert region is not less than that of the catalyst a and the catalyst B.

Preferably, the filler of the inert zone is inert glass beads and/or ceramic rings.

Preferably, the temperature is 120-200 ℃, the pressure is 0.1-2.0 MPa, and the mass space velocity is 0.05-2.0 h^-1。

Preferably, after the catalyst A and the catalyst B are completely filled, inert gas is blown to purge before the reaction.

Preferably, the inert gas is one of nitrogen, helium and argon.

Preferably, the purging temperature is 150-450 ℃, the purging flow rate of the inert gas is 80-200 mL/min, and the purging time is 0.5-5 h.

Preferably, the aromatic hydrocarbon raw material is crude aromatic oil or a hydrocarbon octaene isomerization product generated by a reforming device.

A combined packed solid catalyst for removing trace olefin from aromatic hydrocarbon comprises a catalyst A and a catalyst B, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst.

Compared with the prior art, the invention has the following advantages:

(1) the catalyst has good activity, the bromine index of the product is low, and the aromatic hydrocarbon loss is small;

(2) compared with the traditional clay catalyst or the existing molecular sieve catalyst, the method for filling the solid catalyst in a combined manner greatly prolongs the overall service life of the catalyst;

(3) different from the traditional clay refining process, the clay catalyst and the molecular sieve catalyst used in the invention form a catalytic system, and the clay catalyst and the molecular sieve catalyst do not need to be replaced frequently;

(4) the catalyst B and the molecular sieve used in the invention have renewable performance, thereby effectively avoiding the generation of solid wastes and having little influence on the environment.

Detailed Description

The present invention will be further described with reference to the following examples.

General examples

A method for removing trace olefin from aromatic hydrocarbon loaded with a solid catalyst combination comprises the following steps: placing an aromatic hydrocarbon raw material in a de-olefin reactor, and respectively passing through two reaction zones from top to bottom under the conditions of temperature and pressure, wherein the two reaction zones are respectively filled with a catalyst A and a catalyst B according to the flowing direction of the aromatic hydrocarbon raw material, wherein the catalyst A is a modified clay adsorbent, and the catalyst B is a modified Y molecular sieve catalyst; the olefin is removed from the aromatic hydrocarbon raw material after chemical adsorption and catalytic reaction.

Preferably, the modified clay adsorbent is acidified activated clay, wherein the acidification is performed by using one of hydrochloric acid, sulfuric acid and mixed acid of nitric acid and phosphoric acid (the mass ratio is 1: 1) in inorganic acid, and the total concentration of the mixed acid aqueous solution is 1.0-12.0 wt%. The modified Y molecular sieve catalyst is a Y molecular sieve modified by acid water solution treatment, the acid is hydrochloric acid or mixed acid (the mass ratio is 1: 2) of phosphoric acid and citric acid, acetic acid and oxalic acid in organic acid, and the total concentration of the mixed acid water solution is 5.0-10.0 wt%.

Preferably, the loading mass ratio of the catalyst A to the catalyst B is 0.1-8: 1.

Preferably, an inert region for isolation is filled between the catalyst a and the catalyst B, and the filling thickness of the inert region is not less than that of the catalyst a and the catalyst B. The filler of the inert zone is inert glass beads and/or ceramic rings.

Preferably, the temperature is 120-200 ℃, the pressure is 0.1-2.0 MPa, and the mass space velocity is 0.05-2.0 h^-1. And after the catalyst A and the catalyst B are filled, inert gas is introduced for purging before reaction.

Preferably, the inert gas is one of nitrogen, helium and argon. The purging temperature is 150-450 ℃, the purging flow rate of the inert gas is 80-200 mL/min, and the purging time is 0.5-5 h.

Preferably, the aromatic hydrocarbon raw material is crude aromatic oil or a hydrocarbon octaene isomerization product generated by a reforming device.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The reaction for removing trace olefin from aromatic hydrocarbon is carried out in a fixed bed reactor (olefin removal reactor), and the inner diameter of the reaction tube is 1.5cm, and the length is 75 cm. The bromine index of the aromatic hydrocarbon as the reaction feed was about 850mgBr/100 g.

Example 1

Taking a proper amount of argil, and treating for 4 hours by adopting nitric acid and hydrochloric acid (the molar ratio is 1: 1) under the conditions that the liquid-solid ratio is 5 and the pickling temperature is 90 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst A. Taking a proper amount of Y molecular sieve catalyst, and treating for 4 hours by adopting hydrochloric acid and citric acid (the molar ratio is 1: 2) under the conditions that the liquid-solid ratio is 4 and the pickling temperature is 95 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst B.

In the reverse directionThe bottom of the reaction tube was filled with an appropriate amount of inert glass beads, then 10g of catalyst B was weighed and placed in the reaction tube, then inert glass beads of 4cm height were filled, then 2g of catalyst A was weighed, and finally the upper part was filled with an appropriate amount of inert glass beads. Purging with nitrogen at 350 deg.C for 3H, cooling to 160 deg.C, and switching to H atmosphere₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.5MPa, and then controlling the mass space velocity to be 1.0h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Example 2

Taking a proper amount of argil, and treating for 4 hours by adopting phosphoric acid and hydrochloric acid (the molar ratio is 1: 1) under the conditions that the liquid-solid ratio is 5 and the pickling temperature is 90 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst A. Taking a proper amount of Y molecular sieve catalyst, and treating for 4 hours by adopting phosphoric acid and citric acid (the molar ratio is 1: 2) under the conditions that the liquid-solid ratio is 4 and the pickling temperature is 95 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst B.

The bottom of the reaction tube is filled with inert glass beads with a certain height, then 10g of catalyst B is weighed and filled into the reaction tube, then inert glass beads with a height of 4cm are filled, then 5g of catalyst A is weighed, and finally the upper part of the reaction tube is filled with a proper amount of inert glass beads. Purging with nitrogen at 350 deg.C for 4H, cooling to 160 deg.C, and switching to H atmosphere₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.5MPa, and then controlling the mass space velocity to be 1.0h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Example 3

Taking a proper amount of argil, and treating for 4 hours by adopting phosphoric acid and hydrochloric acid (the molar ratio is 1: 1) under the conditions that the liquid-solid ratio is 5 and the pickling temperature is 90 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst A. Taking a proper amount of Y molecular sieve catalyst, and treating for 4 hours by adopting phosphoric acid and citric acid (the molar ratio is 1: 2) under the conditions that the liquid-solid ratio is 4 and the pickling temperature is 95 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst B.

Filling inert glass beads with a certain height at the bottom of the reaction tube, then weighing 10g of catalyst B, filling the catalyst B into the reaction tube, then filling inert glass beads with a height of 4cm, then weighing 10g of catalyst A, and finally filling a proper amount of inert glass beads at the upper part. Purging with nitrogen at 350 deg.C for 4H, cooling to 150 deg.C, and switching to H₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.5MPa, and then controlling the mass space velocity to be 1.0h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Example 4

Taking a proper amount of argil, and treating for 4 hours by adopting nitric acid and hydrochloric acid (the molar ratio is 1: 1) under the conditions that the liquid-solid ratio is 5 and the pickling temperature is 90 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst A. Taking a proper amount of Y molecular sieve catalyst, and treating for 4 hours by adopting hydrochloric acid and citric acid (the molar ratio is 1: 2) under the conditions that the liquid-solid ratio is 4 and the pickling temperature is 95 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst B.

The bottom of the reaction tube is filled with inert glass beads with a certain height, then 10g of catalyst B is weighed and filled into the reaction tube, then inert glass beads with a height of 4cm are filled, then 20g of catalyst A is weighed, and finally the upper part of the reaction tube is filled with a proper amount of inert glass beads. Purging with nitrogen at 350 deg.C for 4H, cooling to 150 deg.C, and switching to H₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.2MPa, and then controlling the mass space velocity to be 1.2h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Comparative example 1

Taking a proper amount of Y molecular sieve catalyst, and treating for 4 hours by adopting hydrochloric acid and citric acid (the molar ratio is 1: 2) under the conditions that the liquid-solid ratio is 4 and the pickling temperature is 95 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst B.

The bottom of the reaction tube is filled with a certain amount ofThen, 10g of catalyst B was weighed out and charged into a reaction tube, and then an appropriate amount of inert glass beads was filled in the upper part. Purging with nitrogen at 350 deg.C for 3H, cooling to 160 deg.C, and switching to H atmosphere₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.5MPa, and then controlling the mass space velocity to be 1.0h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Comparative example 2

Taking a proper amount of argil, and treating for 4 hours by adopting nitric acid and hydrochloric acid (the molar ratio is 1: 1) under the conditions that the liquid-solid ratio is 5 and the pickling temperature is 90 ℃. And carrying out the steps of suction filtration, washing, drying, roasting and the like to obtain the catalyst A.

The bottom of the reaction tube was filled with inert glass beads of a certain height, then 10g of catalyst a was weighed and charged into the reaction tube, and then the upper part was filled with an appropriate amount of inert glass beads. Purging with nitrogen at 350 deg.C for 4H, cooling to 160 deg.C, and switching to H atmosphere₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.5MPa, and then controlling the mass space velocity to be 1.0h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Comparative example 3

Filling inert glass beads with a certain height at the bottom of a reaction tube, then weighing 10g of unmodified Y molecular sieve, filling the unmodified Y molecular sieve into the reaction tube, then filling inert glass beads with a height of 4cm, then weighing 20g of unmodified argil, and finally filling a proper amount of inert glass beads at the upper part. Purging with nitrogen at 350 deg.C for 4H, cooling to 150 deg.C, and switching to H₂Used for controlling the system pressure of the reaction system, then controlling the reaction pressure to be 1.2MPa, and then controlling the mass space velocity to be 1.2h^-1The aromatic hydrocarbon feedstock was fed into the reactor, and the reactor outlet product was analyzed for bromine index using a bromine index tester, the results of which are shown in Table 1.

Table 1:

as can be seen from Table 1, the final effect of the method for removing trace olefin from aromatic hydrocarbon loaded by adopting the solid catalyst combination is obviously better than that of a single clay catalyst or a Y molecular sieve catalyst. Moreover, the activity and stability of the catalyst are effectively reduced by modifying the catalyst. The bromine index of the reaction raw material is effectively reduced by adopting the combined filling of the modified clay and the modified Y molecular sieve in the embodiments 1 to 4, the bromine index is basically kept below 40 in the continuous reaction time of 30 days, and the bromine index can be basically maintained at a lower level in the continuous reaction time of 30 days. However, the combined loading of catalyst A and catalyst B alone or unmodified clay and Y molecular sieve in comparative examples 1-3 was significantly lower than the catalyst performance in the examples in both 30-day and 90-day long-lasting reactions. This shows that the catalyst system obtains better stability while the combined loading method of the catalyst A and the catalyst B effectively removes trace olefin in aromatic hydrocarbon.

The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.