CN107974280B

CN107974280B - Liquid acid alkylation reaction method

Info

Publication number: CN107974280B
Application number: CN201610937335.5A
Authority: CN
Inventors: 袁清; 董明会; 毛俊义; 黄涛; 王雷; 秦娅
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2016-10-25
Filing date: 2016-10-25
Publication date: 2020-05-19
Anticipated expiration: 2036-10-25
Also published as: CN107974280A

Abstract

A liquid acid alkylation reaction method adopts an alkylation reactor which comprises a light phase separation zone (I), a reaction zone (III), a circulation zone (II) and a heavy phase settling zone (IV) from top to bottom, wherein two ends of the reaction zone (III) and two ends of the circulation zone (II) are respectively communicated, a dispersed phase feeder (4) is arranged at the bottom of the reaction zone (III), and a continuous phase inlet (1) is arranged in the circulation zone (II) on the side wall of the reactor; the reaction zone and the circulation zone are reaction mixture of liquid acid catalyst, the mixture of isoparaffin and olefin enters the reaction zone through a disperse phase feeder, the isoparaffin and the olefin are subjected to alkylation reaction under the alkylation reaction condition, the reaction product enters the circulation zone after the alkylation reaction, the light phase enters a light phase separation zone at the upper part of the reactor, the heavy phase enters a heavy phase settling zone at the lower part of the reactor, the alkylation reaction product is extracted from a light phase outlet, and the waste liquid catalyst is extracted from a heavy phase outlet. The liquid acid alkylation reaction provided by the invention has high selectivity.

Description

Liquid acid alkylation reaction method

Technical Field

The present invention relates to an alkylation reaction process, and more particularly, to a liquid acid alkylation reaction process employing a novel alkylation reactor.

Technical Field

With the increasing rigor of environmental regulations, the production of clean fuels is becoming more important in the majority of oil refineries. Although an oil refinery has various gasoline blending components such as catalytic cracking gasoline, reformed gasoline, alkylate, isomerate and etherified gasoline, compared with other blending components, alkylate has the advantages of no olefin and aromatic hydrocarbon, extremely low sulfur content and the like, so that great attention is paid to the alkylate technology, and the alkylation technology is continuously developed. With the continuous improvement of alkylation process technology, the status of alkylation unit in the production of oil refining industry is becoming more and more important.

Alkylation refers to the production of an alkylate product from isoparaffins and light olefins over an acidic catalyst, which alkylate product typically has a higher octane number than the feedstock and is a gasoline fraction. In petroleum refining, this reaction is commonly referred to as the reaction of C3-C5 olefins with isobutane. The alkylation catalyst comprises liquid acid and solid acid, wherein the liquid acid catalyst mainly comprises hydrofluoric acid, sulfuric acid or ionic liquid and the like.

The liquid acid catalyzed alkylation reaction is generally operated at a low temperature, which is beneficial to reduce the occurrence of side reactions and can improve the selectivity of the product. In conventional processes, the hydrocarbon feedstock is dispersed in a continuous acid liquor, and therefore the acid is used in relatively large quantities. Although this method requires the use of strong acid as a catalyst, is very corrosive to equipment, produces waste residues that pollute the environment, and causes damage to the human body by hydrofluoric acid, there are no other effective methods that can completely replace this method, and liquid acid catalyzed alkylation is still the major method currently used in the world for producing high octane gasoline components.

Most of the current research on liquid acids has focused on improving and upgrading the liquid acid alkylation reactor and the acid hydrocarbon separation equipment to reduce its adverse effects. Specifically, the following are included in the reactor:

CN101104570A discloses a liquid acid alkylation process, which comprises: introducing a hydrocarbon component consisting essentially of an olefin, an olefin precursor or mixture thereof and an isoparaffin into a downflow reaction zone comprising a disperser; incorporating a vaporization zone into a vessel comprising the reaction zone or into a separate vessel further comprising a disperser; operating the vaporization region at the bubble point of said hydrocarbon component such that vaporization of the hydrocarbon is operated at the outlet in a pulsed flow regime or near pulsed flow regime by adjusting the flow ratio of hydrocarbon/acid/steam in said vaporization region.

US5785933 discloses a sulfuric acid alkylation reactor comprising: a reactor vessel having a vertical cylindrical wall, a top, an inverted conical bottom, and an internally perforated baffle; a settling vessel for separating the sulfuric acid catalyst from the alkylate; a transfer pipe having a vertical portion suspended in the middle of the reactor, a horizontal portion sealed through the cylindrical wall of the reactor and communicating with the settling vessel, the transfer pipe having a first end disposed toward the inverted conical bottom and a second end located at the top of the settling vessel; and a plurality of emulsion injection pipes tangentially disposed and communicating with the interior of the reactor, for injecting reactants into the reaction vessel.

US4075258 discloses an improved alkylation process based on the discovery that stirring an alkylation medium above a critical mixing intensity can increase the motor octane number of the resulting alkylate, and thus the process uses a reactor in which mixing elements are provided.

CN101679143A discloses a system for alkylating hydrocarbons containing at least one isoparaffin and at least one olefin, the system comprising: at least one external high shear mixing device comprising at least one rotor and at least one stator separated by a shear gap, wherein the shear gap is the minimum distance between the at least one rotor and the at least one stator, wherein the high shear mixing device is capable of producing a tip speed of greater than 22.9m/s at the tip of the at least one rotor; a pump configured to route a pressurized liquid stream containing a liquid acid catalyst into at least one shear mixing device; and a vessel configured to receive the emulsion from the high shear mixing device.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a liquid alkylation reaction method adopting a novel reactor.

A liquid acid alkylation reaction method adopts an alkylation reactor which comprises a light phase separation zone I, a reaction zone III, a circulation zone II and a heavy phase sedimentation zone IV from top to bottom, wherein two ends of the reaction zone III and two ends of the circulation zone II are respectively communicated, a dispersed phase feeder 4 is arranged at the bottom of the reaction zone III, the dispersed phase feeder 4 is communicated with a dispersed phase inlet 3 at the bottom of the reactor, a continuous phase inlet 1 is arranged at the circulation zone II on the side wall of the reactor, a light phase outlet 2 is arranged at the top of the light phase separation zone I, and a heavy phase outlet 5 is arranged at the bottom of the heavy phase sedimentation zone IV; the reaction area and the circulation area are filled with reaction mixture containing liquid acid catalyst, the mixture of isoparaffin and olefin enters the reaction area through a disperse phase feeder, the isoparaffin and the olefin are subjected to alkylation reaction under the alkylation reaction condition, the reactant flow enters the circulation area, the light phase of the reactant flow enters a light phase separation area at the upper part of the reactor, the heavy phase enters a heavy phase settling area at the lower part of the reactor, the alkylation reaction product is extracted from a light phase outlet, and the waste liquid catalyst is extracted from a heavy phase outlet.

The liquid acid alkylation reaction method provided by the invention has the beneficial effects that:

the liquid acid alkylation reaction method provided by the invention adopts a novel alkylation reactor, which comprises a light phase separation zone, a reaction zone, a circulation zone and a heavy phase settling zone, wherein a dispersed phase feeder is arranged at the bottom of the reaction zone, and alkylation reaction raw materials are dispersed in a reaction mixture containing a liquid acid catalyst in the form of micro liquid drops, so that the interphase mass transfer surface of the alkylation reaction raw materials and the liquid acid catalyst is improved, and the improvement of the reaction efficiency is facilitated; the circulation area is arranged to realize the in-reactor circulation of the liquid acid catalyst, and compared with a reactor which carries out the external circulation by a mechanical pump, the reactor is beneficial to reducing the energy consumption of the device.

Drawings

FIG. 1 is a schematic flow diagram of a liquid phase computer alkylation reaction method provided by the present invention.

FIG. 2 is a schematic diagram of the reaction zone and the circulation zone in the alkylation reactor.

FIG. 3 is a schematic illustration of packing in the light phase separation zone of an alkylation reactor.

FIG. 4 is a schematic view of the baffle arrangement in the light phase separation zone of the alkylation reactor.

Reference numerals:

1-continuous phase inlet, 2-light phase outlet, 3-dispersed phase inlet, 4-dispersed phase feeder, 5-heavy phase outlet; i-light phase separation zone, II-circulation zone, III-reaction zone and IV-heavy phase settling zone.

Detailed Description

The liquid phase alkylation reactor provided by the present invention is further described with reference to the accompanying drawings and the detailed description thereof, but the present invention is not limited thereto.

A liquid acid alkylation reaction method adopts an alkylation reactor which comprises a light phase separation zone I, a reaction zone III, a circulation zone II and a heavy phase sedimentation zone IV from top to bottom, wherein two ends of the reaction zone III and two ends of the circulation zone II are respectively communicated, a dispersed phase feeder 4 is arranged at the bottom of the reaction zone III, the dispersed phase feeder 4 is communicated with a dispersed phase inlet 3 at the bottom of the reactor, a continuous phase inlet 1 is arranged at the circulation zone II on the side wall of the reactor, a light phase outlet 2 is arranged at the top of the light phase separation zone I, and a heavy phase outlet 5 is arranged at the bottom of the heavy phase sedimentation zone IV; the reaction zone and the circulation zone are filled with a reaction mixture containing a liquid acid catalyst, the mixture of isoparaffin and olefin enters the reaction zone through a disperse phase feeder, the isoparaffin and the olefin are subjected to alkylation reaction under the alkylation reaction condition, the reaction product enters the circulation zone after the reaction, the light phase enters a light phase separation zone at the upper part of the reactor, the heavy phase enters a heavy phase settling zone at the lower part of the reactor, an alkylation reaction product is extracted from a light phase outlet, and a waste liquid catalyst is extracted from a heavy phase outlet.

In the liquid acid alkylation reaction method provided by the invention, the dispersed phase feeder adopts a pressure type feeder, a certain pressure difference exists between the mixture of isoparaffin and olefin in the dispersed phase feeder and the reactor, and the fluid is dispersed into tiny droplets by converting the pressure difference potential energy into the kinetic energy and the surface energy of the dispersed phase fluid. Preferably, the pressure difference between the mixture of isoparaffin and olefin before and after feeding is 0.02-3.0MPa, the initial flow rate of the mixture of isoparaffin and olefin entering the outlet of the disperse phase feeder is 2-40m/s, and the diameter of the droplets of the mixture of isoparaffin and olefin at the outlet of the disperse phase feeder is 0.1-1000 μm.

In the liquid acid alkylation reaction method provided by the invention, the hydrocarbon raw material and the liquid acid catalyst for alkylation reaction are conventional raw materials and catalysts for alkylation reaction. Preferably, the liquid acid catalyst is selected from one or more of hydrofluoric acid, sulfuric acid, trifluoromethanesulfonic acid and ionic liquid; the isoparaffin is one or more of isoparaffin of C3-C7; the olefin is C3-C5 monoolefin; the mole ratio of the isoparaffin to the olefin in the mixture of isoparaffin and olefin is 100-500: 1.

Preferably, the alkylation reaction conditions are as follows: the temperature is-20 ℃ to 100 ℃, and the reaction pressure is 0.1MPa to 2 MPa.

Preferably, the dispersed phase feeder 4 is a perforated pipe, a sintered metal pipe or an atomizing nozzle.

The reaction zone III is a single reaction tube or a plurality of reaction tubes arranged, wherein the bottom of each reaction tube is provided with a corresponding dispersed phase feeder 4. Preferably, the reaction zone has a plurality of reaction tubes arranged therein.

Preferably, the cross-sectional area of the circulation zone II is 0.8 to 4.0 times, more preferably 1.0 to 3.5 times the total cross-sectional area of the reaction zone III.

Preferably, the light phase separation zone I is 1.0-3.0 times of the outer diameter of the circulation zone II. The heavy phase settling zone IV is 1.0-3.0 times of the outer diameter of the circulating zone II.

Preferably, a filler or a baffle is arranged in the light phase separation zone I and/or the heavy phase settling zone IV for improving the liquid-liquid separation efficiency.

preferably, baffles are arranged in the light phase separation zone I, the baffles are obliquely arranged and staggered, the inclination angle β is 5-30 degrees, more preferably, the baffles are provided with small holes, and the diameter of each hole is 1-10 mm.

In the liquid acid alkylation process provided by the present invention, the alkane and alkene starting materials are fed as a dispersed phase from the bottom of the reaction zone via a dispersed phase feeder and are highly dispersed in the form of fine droplets in the reaction mixture containing the liquid acid catalyst. Fresh liquid acid catalyst is added from a continuous phase inlet in the middle of the circulating area, flows to an inlet end at the bottom of the reaction area along with the circulating liquid acid catalyst, is carried by the high-speed upward flowing alkylation raw material and enters the reaction area, and catalyzes the alkylation reaction of alkane and alkene. At the reaction zone outlet, the reaction mixture rapidly achieves bulk phase separation due to density differences as the fluid velocity drops rapidly, with the alkylation reaction product and unreacted alkane flowing upward into the light phase separation zone and the liquid acid catalyst entering the loop zone and flowing downward. In the light phase separation zone and the heavy phase settling zone, the entrained light and heavy components are further separated, the hydrocarbon phase is extracted from the top of the reactor, and the waste acid catalyst is discharged from the bottom of the reactor.

The liquid acid catalyst can be various liquid acids with catalytic action on the alkylation reaction of isoparaffin and olefin, preferably one or more of hydrofluoric acid, sulfuric acid trifluoromethanesulfonic acid, ionic liquid and the like, and more preferably sulfuric acid or hydrofluoric acid. The alkane refers to isoparaffin, preferably one or more of C3-C7 isoparaffin, for example, isobutane and/or isopentane, more preferably isobutane. The olefin is an organic compound having a carbon-carbon double bond (-C ═ C-) in the molecular structure, preferably a C3-C5 monoolefin, and may be one or more of propylene and a carbon tetraene-carbon pentaolefin, and more preferably a carbon tetraene. The relative proportions of isoparaffin and olefin may be conventionally selected. Generally, the molar ratio of isoparaffin to olefin in the reaction zone may be in the range of from 50 to 600:1, preferably from 100 to 500: 1.

In the liquid acid alkylation method provided by the invention, the alkylation reaction conditions are conventional alkylation reaction conditions, wherein the reaction temperature is-20-100 ℃, preferably-10-50 ℃, and more preferably-5-40 ℃; the reaction pressure is preferably to maintain the reaction system in a liquid phase, and may be 0.1MPa to 2MPa, preferably 0.3MPa to 0.6 MPa.

In the liquid acid alkylation method provided by the invention, the dispersed phase feeder adopts a pressure type feeder, and the feeder is selected from one or a combination of a plurality of porous pipes, sintered metal pipes and atomizing nozzles. A certain pressure difference exists between the dispersed phase main fluid and the reactor, and the fluid is dispersed into tiny droplets by converting the pressure difference potential energy into the kinetic energy and the surface energy of the dispersed phase fluid. After entering the reactor, the liquid drops are sheared with the continuous phase fluid to be broken again, so that the size of the liquid drops is further reduced.

The isoparaffin and olefin enter the bottom of the reaction zone through a dispersed phase feeder, the pressure difference between the main fluid and the reactor in the dispersed phase feeder is 0.02-3.0MPa, the initial flow rate of a fluid outlet of the dispersed phase feeder is 2-40m/s, and the diameter of the isoparaffin and olefin liquid drops serving as the dispersed phase is 0.1-1000 mu m.

In the reaction zone, isoparaffin and olefin are dispersed in a liquid acid catalyst serving as a continuous phase in the form of micro-droplets, so that a very large mass transfer surface is favorable for strengthening mass transfer and reaction, and meanwhile, the continuous phase is driven to pass through the whole reaction zone together in a plug flow manner due to the high flow velocity of a dispersed phase, so that local back mixing is favorably reduced.

In the circulation zone, the alkylation feed and the liquid acid catalyst are separated primarily by density differences, with the light phase bulk entering a light phase separation zone at the top of the reactor and the heavy phase bulk entering a heavy phase settling zone at the bottom of the reactor.

the diameters of the light phase separation zone and the heavy phase settling zone are 1.0-3.0 times of the diameter of the circulation zone, the vertical angle of the transition section is 0-60 degrees, the two phases are separated by density difference in the light phase separation zone and the heavy phase settling zone, or accelerated phase separation is carried out by adding a coalescence material, and the coalescence material can adopt two forms of filler and baffle, wherein the baffle is obliquely arranged and staggered, the range of the inclination angle beta is 5-30 degrees, small holes are arranged on the baffle, the diameter of the holes is 1-10mm, and the retention time of the fluid in the light phase separation zone and the heavy phase settling zone is 0.1-2 hours in the using process.

FIG. 1 is a schematic flow diagram of a liquid acid alkylation reaction method provided by the present invention. As can be seen from FIG. 1, the liquid acid catalyst enters the loop zone II from the continuous phase inlet 1 and flows down to the inlet of the reaction zone III after mixing with the reaction mixture. Alkylation reaction raw materials are introduced from a dispersed phase inlet 3, dispersed into micro droplets by a dispersed phase feeder 4 and then enter a reaction zone III. The pressure difference range before and after the dispersed phase feeder is 0.02-3.0MPa, and the initial flow velocity of the dispersed phase fluid outlet is 2-40 m/s. At the inlet end of the reaction zone III, the droplets and the continuous phase fluid are sheared and collided mutually to finish secondary crushing, so that the size of the droplets is further reduced, and meanwhile, the high-speed droplet flow carries most of the continuous phase fluid to enter the reaction zone III and finish mass transfer and reaction of active components. At the outlet end of the reaction zone III, the main separation of the light phase and the heavy phase is realized due to the density difference because the fluid velocity of the reactant flow is reduced, and the further separation of the light phase and the heavy phase is realized in the circulating zone II, wherein the light phase is enriched upwards, and the heavy phase flows downwards. The light phase main body carries a small amount of heavy phase to enter a light phase separation zone I, and the heavy phase fluid carries a part of light phase to enter a heavy phase settling zone IV. The separated light phase is taken out from an outlet 2 at the top of the reactor, and the settled heavy phase is taken out from a heavy phase outlet 5 at the bottom of the reactor.

in order to accelerate the two-phase separation, a conglomerate material can be optionally placed in the light phase separation zone I and the heavy phase settling zone IV, the conglomerate material can adopt two forms of filling materials and baffles, preferably baffles, wherein the baffles are obliquely placed and staggered, the inclination angle β ranges from 5 degrees to 30 degrees, small holes are formed in the baffles, and the diameter of each hole is 1 mm to 10 mm.

The following examples illustrate the utility of a reactor for liquid acid alkylation in accordance with the present invention.

Example 1

The alkylation reactor used is shown in figure 1, wherein the reaction zone is a single reaction tube with a diameter of 22mm, the total height of the reaction zone is 1600mm, the diameter of the circulation zone is 40mm, the effective sectional area of the circulation zone is 2.3 times of the total sectional area of the reaction zone, the diameter of the light phase separation zone is 2.0 times of the outer diameter of the circulation zone, the vertical angle of the transition section is 30 degrees, the diameter of the heavy phase separation zone is 1.2 times of the outer diameter of the circulation zone, the light phase and the heavy phase freely settle by gravity, the material residence time in the light phase separation zone is 40min, and the material residence time in the heavy phase settlement zone is 1.

Isobutane as a raw material of isoparaffin was purchased from beijing huayuan gas chemical company ltd, and the composition thereof is listed in table 1; the etherified carbon four was used as the olefin feedstock from an oil refinery MTBE unit from swinship division, petrochemical gmbh, and the composition is listed in table 1. Concentrated sulfuric acid (with the mass concentration of 94%) serving as a catalyst enters a circulation zone of the reactor through an inlet 1, a mixed raw material of isoparaffin and olefin enters the bottom of a reaction zone through a dispersed phase feeder, the mixed raw material and the catalyst flow upwards in a reaction tube and carry out alkylation reaction, the dispersed phase feeder is an atomizing nozzle, the pressure difference between the front part and the back part is 1.0MPa, and the flow velocity of an outlet of the nozzle is 25 m/s. The volume ratio of isoparaffin to olefin in the raw material is 300: 1; controlling the reaction temperature to be 6-10 ℃; the apparent pressure in the reactor was 0.5 MPa.

The composition of the alkylate was analyzed by gas chromatography (see RIPP 80-90, eds. petrochemical analysis methods, Yangchi et al, 1990) and the results are given in Table 2. The selectivity of the reaction was evaluated as the molar ratio of Trimethylpentane (TMP) and Dimethylhexane (DMH) as alkylation products TMP/DMH. Since trimethylpentane has a higher octane number, a higher TMP/DMH ratio indicates a better selectivity.

Example 2

The alkylation reactor used in example 2 had a plurality of reaction tubes disposed in the reaction zone, as shown in fig. 2, the diameter of the single tube in the reaction zone was 30mm, the total height of the reaction zone was 2400m, the diameter of the circulation zone was 120mm, the effective cross-sectional area of the circulation zone was 1.3 times the total cross-sectional area of the reaction zone, the diameter of the light phase separation zone was 1.5 times the outer diameter of the circulation zone, the vertical angle of the transition zone was 45 °, the diameter of the heavy phase separation zone was the same as the outer diameter of the circulation zone, the residence time of the material in the light phase separation zone was 1h, the residence time of the material in the heavy phase settling zone was 1.5 h.

The alkylation feed used was the same as in example 1 for isoparaffins and olefins. Hydrofluoric acid (with the mass concentration of 88%) serving as a catalyst is fed into a circulation zone of the reactor through a continuous phase inlet, a mixed raw material of isoparaffin and olefin enters a reaction zone through a dispersed phase feeder at the bottom of a reaction tube, and flows upwards together with the catalyst in the reaction tube to perform alkylation reaction, wherein the dispersed phase feeder is a metal sintering tube, and the pressure difference between the front and the back is 0.4 MPa. The volume ratio of isoparaffin to olefin in the raw material is 200: 1; the reaction temperature is 35-40 ℃; the apparent pressure in the reactor was 0.6 MPa. The results of the composition of the alkylation product are set forth in table 2.

TABLE 1

TABLE 2

Claims

1. A liquid acid alkylation reaction method is characterized in that an adopted alkylation reactor comprises a light phase separation zone (I), a reaction zone (III), a circulation zone (II) and a heavy phase settling zone (IV) from top to bottom, wherein two ends of the reaction zone (III) and two ends of the circulation zone (II) are respectively communicated, a dispersed phase feeder (4) is arranged at the bottom of the reaction zone (III), the dispersed phase feeder (4) is communicated with a dispersed phase inlet (3) at the bottom of the reactor, a continuous phase inlet (1) is arranged at the circulation zone (II) on the side wall of the reactor, a light phase outlet (2) is arranged at the top of the light phase separation zone (I), a heavy phase outlet (5) is arranged at the bottom of the heavy phase settling zone (IV), and the sectional area of the circulation zone (II) is 0.8-4.0 times of the total sectional area of the reaction zone (III); the reaction area and the circulation area are filled with reaction mixture containing liquid acid catalyst, the mixture of isoparaffin and olefin enters the reaction area through a disperse phase feeder, the isoparaffin and the olefin are subjected to alkylation reaction under the alkylation reaction condition, the reactant flow enters the circulation area, the light phase of the reactant flow enters a light phase separation area at the upper part of the reactor, the heavy phase enters a heavy phase settling area at the lower part of the reactor, the alkylation reaction product is extracted from a light phase outlet, and the waste liquid catalyst is extracted from a heavy phase outlet.

2. The liquid acid alkylation reaction process of claim 1, wherein the pressure difference between the front and the back of the mixture of isoparaffin and olefin is 0.02 to 3.0MPa, the initial flow rate of the mixture of isoparaffin and olefin into the outlet of the dispersed phase feeder is 2 to 40m/s, and the diameter of the droplets of the mixture of isoparaffin and olefin at the outlet of the dispersed phase feeder is 0.1 to 1000 μm.

3. The liquid acid alkylation reaction process of claim 1, wherein the liquid acid catalyst is selected from one or more of hydrofluoric acid, sulfuric acid, trifluoromethanesulfonic acid, and ionic liquids; the isoparaffin is one or more of isoparaffin of C3-C7; the olefin is C3-C5 monoolefin; the mole ratio of the isoparaffin to the olefin in the mixture of isoparaffin and olefin is 100-500: 1.

4. The liquid acid alkylation reaction process of claim 1, wherein the alkylation reaction conditions are: the temperature is-20 ℃ to 100 ℃, and the reaction pressure is 0.1MPa to 2 MPa.

5. A liquid acid alkylation process according to claim 1, characterized in that the dispersed phase feeder (4) is a perforated pipe, a sintered metal pipe or an atomizing nozzle.

6. The liquid acid alkylation reaction process of claim 1, wherein the cross-sectional area of the circulation zone (II) is 1.0 to 3.5 times the total cross-sectional area of the reaction zone (III).

7. The liquid acid alkylation reaction process of claim 1, wherein the light phase separation zone (I) is 1.0 to 3.0 times the outer diameter of the loop zone (II).

8. The liquid acid alkylation reaction process of claim 1, wherein the heavy phase settling zone (IV) is 1.0 to 3.0 times the outer diameter of the loop zone (II).

9. The liquid acid alkylation reaction process according to any one of claims 1 to 8, wherein packing or baffles are provided in the light phase separation zone (I) and/or the heavy phase settling zone (IV).

10. the liquid acid alkylation reaction process according to claim 9, wherein baffles are provided in the light phase separation zone (I), and the baffles are obliquely arranged and staggered with an inclination angle β of 5 to 30 °.

11. The liquid acid alkylation reaction process of claim 10, wherein the baffle plate has a small hole with a diameter of 1 to 10 mm.