阅读说明：本技术 一种工业异辛烷生产系统 (Industry isooctane production system ) 是由 杨昆峰 钱瑜 李盛昌 马国庆 陈星良 于 2020-05-20 设计创作，主要内容包括：一种工业异辛烷生产系统,由原料预处理单元、反应单元、制冷压缩单元、精制与分馏单元和化学处理单元组成；原料预处理单元的脱轻烃塔顶回流罐连接到反应单元的反应器,反应单元的闪蒸罐分出三条管路,一条管路连接到制冷压缩单元的压缩机入口分液罐,另一条管路连接到化学处理单元的排酸罐,还有一条连接至精制与分馏单元的馏出物酸洗罐。本发明系统对传统工艺系统进行了改进优化,进而降低了系统能耗,提高了产品质量,同时提高了系统运转的可靠性和稳定性,与国内现有硫酸异辛烷工艺相比,工业异辛烷收率提高约10％,辛烷值提高约2个单位,酸耗降低约30％,能耗降低约35％。(An industrial isooctane production system comprises a raw material pretreatment unit, a reaction unit, a refrigeration compression unit, a refining and fractionation unit and a chemical treatment unit; the top reflux tank of the light hydrocarbon eliminating tower of the material pre-treating unit is connected to the reactor of the reaction unit, the flash evaporating tank of the reaction unit has three separated pipelines, one pipeline is connected to the liquid separating tank in the compressor of the refrigerating and compressing unit, the other pipeline is connected to the acid draining tank of the chemical treating unit, and the other pipeline is connected to the distillate acid washing tank of the refining and fractionating unit. Compared with the domestic existing isooctane sulfate process, the yield of industrial isooctane is improved by about 10 percent, the octane number is improved by about 2 units, the acid consumption is reduced by about 30 percent, and the energy consumption is reduced by about 35 percent.)

1. An industrial isooctane production system is characterized by comprising a raw material pretreatment unit, a reaction unit, a refrigeration compression unit, a refining and fractionation unit and a chemical treatment unit;

the raw material pretreatment unit comprises a feeding buffer tank (V-6101), the feeding buffer tank (V-6101) is connected to a light hydrocarbon removing tower (T-6010) through a feeding pump (P-6101A/B), and a heat exchanger (E-6101A/B) is arranged between the feeding pump (P-6101A/B) and the light hydrocarbon removing tower (T-6010); the light dydrocarbon removing tower (T-6010) is connected with a light dydrocarbon removing tower top reflux tank (V-6102) through a condenser (E-6102A/B), the bottom of the reflux tank (V-6102) is connected with a reflux pump (P-6102A/B), the outlet of the reflux pump (P-6102A/B) is divided into two pipelines, one is used as reflux to return to the top of the light dydrocarbon removing tower (T-6010), and the other is communicated with the outside of the system and is used for conveying a byproduct C3; the bottom of the light dydrocarbon removal tower (T-6010) is connected to a raw material coalescer (V-6103) through a heat exchanger (E-6101A/B), and a carbon four cooler (E-6105A/B) is also arranged between the heat exchanger (E-6101A/B) and the raw material coalescer (V-6103);

the reaction unit comprises a raw material mixer (M-6201), after mixing a carbon four raw material, circulating isobutane and a circulating refrigerant, connecting the mixture to three reactors (R-6201A/B/C) in three ways, wherein each reactor (R-6201A/B/C) is connected with an acid hydrocarbon settler (V-6202A/B/C) through an ascending pipe, the acid hydrocarbon settler (V-6202A/B/C) is provided with three outlets, namely an upper outlet, a lower outlet and a lower outlet, one lower outlet is connected to an inlet of the reactor (R-6201A/B/C) through a descending pipe, the other lower outlet is connected to a waste acid dealkylation tank (V-6301), and the upper outlet is connected to a flash tank (V-6203); the unit is also provided with a fresh acid storage tank (V-6303) for receiving fresh sulfuric acid sent from the device;

the refrigeration compression unit comprises a compressor inlet liquid separation tank (V-6204) and a refrigerant tank (V-6205), the compressor inlet liquid separation tank (V-6203) is connected with the flash tank (V-6203), the top of the compressor inlet liquid separation tank (V-6204) is connected to the refrigeration compressor (C-6201), and the refrigeration compressor (C-6201) is sequentially connected with a refrigerant air cooler (A-6201A-H) and the refrigerant tank (V-6205); the flash tank (V-6203) is provided with a middle partition plate, the upper part of the flash tank is provided with two inlets and 1 outlet, the lower part of the flash tank is provided with three outlets, one inlet of the upper part of the flash tank is connected to the upper outlet of the acid hydrocarbon settler (V-6202A/B/C), the other inlet of the flash tank is respectively connected to the bottom of the compressor inlet liquid separation tank (V-6204) and the bottom of the refrigerant tank (V-6205) through a tee joint, the outlet of the upper part of the flash tank is connected to the middle part of the compressor inlet liquid separation tank (V-6204), and one outlet of the lower part of the flash tank is connected to the raw material carbon four-feed heat exchanger (E-6201A/B/C/D; the other outlet of the lower part is connected to the feed line of the reactor (R-6201A/B/C) through a circulating refrigerant pump (P-6202A/B), and the outlet of the middle part is connected to an acid discharge tank (V-6302) through an acid discharge pump (P-6204A/B);

the refining and fractionating unit comprises a distillate acid washing tank (V-6209), the upper part of the distillate acid washing tank is connected to the upper inlet of the effluent alkali washing tank (V-6210) through an effluent alkali washing mixer (M-6203), the upper outlet of the effluent alkali washing tank (V-6210) is connected to the upper inlet of the effluent water washing tank (V-6211) through an effluent water washing mixer (M-6204), the upper outlet of the effluent water washing tank (V-6211) is connected to the middle part of an isobutane stripping tower (T-6201) through an isooctane-isobutane tower feed heat exchanger (E-6213), wherein, the lower part of the effluent alkaline washing tank (V-6210) and the lower part of the effluent water washing tank (V-6211) are respectively self-circulated by an alkaline washing circulating pump (P-6207A/B) and a water washing circulating pump (P-6208A/B); the top of the deisobutanizer (T-6201) is connected to the inlet of the tower top reflux tank (V-6212) through a deisobutanizer tower top wet air cooler (A-6202A/B/C), the outlet of the tower top reflux tank (V-6212) is divided into two paths through a deisobutanizer tower reflux pump (P-6209A/B), one path returns to the top of the deisobutanizer (T-6201), the other path is connected to a pipeline between the raw material coalescer (V-6103) and the reaction feed heat exchanger (E-6201A/B/C/D) (circulating reaction is carried out), the bottom of the deisobutanizer (T-6201) is connected to the middle part of the deisobutanizer (T-6202), the top of the deisobutanizer (T-6202) is connected to the inlet of the tower top normal butane reflux tank (V-6214) through the tower top wet air cooler (A-6203A/B), the outlet of the n-butane tower top reflux tank (V-6214) is divided into two paths by an n-butane tower reflux pump (P-6210A/B), wherein one path returns to the top of the n-butane removal tower (T-6202), and the other path leads to an n-butane product outlet area; the bottom of the de-n-butane tower (T-6202) passes through an isooctane product pump (P-6211A/B) and leads to an isooctane product outlet area after passing through an isooctane-isobutane tower feed heat exchanger (E-6213); the refining and fractionating unit is also provided with two desalted water buffer tanks 1(V-6305) and 2(V-6303) which are connected in series and are respectively connected to the bottoms of the effluent water washing tank (V-6211) and the effluent alkaline washing tank (V-6210);

the chemical treatment unit comprises a waste acid hydrocarbon removal tank (V-6301), wherein the lower outlet of the waste acid hydrocarbon removal tank is connected to an acid discharge tank (V-6302), the lower part of the acid discharge tank (V-6302) is provided with two outlets, one of the two outlets is connected to a reactor (R-6201A/B/C), the other outlet is connected to a waste acid recovery device, the upper outlet is connected to the middle part of an acid gas-containing alkaline tower (T-6301), the top part of the acid gas-containing alkaline tower (T-6301) is connected to a vent pipe, and the lower parts of the acid gas-containing alkaline tower are respectively returned to the tower through an alkaline tower circulating pump (P-; the unit is also provided with a storage tank (V-6304) for fresh acid (98% H2SO 4) to receive fresh sulfuric acid from the unit.

2. The industrial isooctane production system of claim 1 wherein said light dydrocarbon removal column (T-6010) has a total of 69 trays, and the feedstock enters the 29 th tray; the overhead pressure was controlled at 1.65 MPaG.

Technical Field

The invention belongs to the field of production of alkylated products, and particularly relates to an industrial isooctane production system.

Background

With the increasing strictness of the environmental protection requirements, higher requirements are put on the olefin content of the motor gasoline. Industrial isooctane is the most ideal blending component for producing clean high octane gasoline. Currently, there are two methods for the synthesis of isooctane, one is indirect alkylation by dimerization hydrogenation of isobutylene to obtain a product, and the other is direct alkylation by reaction of isobutane and butene to obtain a product. The direct alkylation process can be classified into three processes according to the kind of catalyst used in the reaction process. The process for preparing isooctane by liquid acid alkylation of isobutane and butene is generally adopted in industry, and mainly comprises a raw material processing system, a reaction system, a refrigeration system, an effluent processing system, a shunting system, an acid-base system and the like. The effluent direct cooling type alkylation process developed by the stratco company is widely applied in industry, and the sulfuric acid alkylation device built in China at present adopts the process. On one hand, the process enables concentrated sulfuric acid and alkane and olefin raw materials to form a larger contact surface, and a high-power stirrer and an internal circulation jacket are arranged in the reactor, so that mass transfer of isobutane to an area of an acid catalyst is increased, and isobutane consumed by reaction in an acid phase can be timely supplemented. The alkylation reactor designed by the CDAlky process of CDTECH company does not have a traditional stirrer, and a unique contactor is added to ensure that the alkane and olefin raw materials and concentrated sulfuric acid are uniformly mixed in a proper temperature range; in addition, the refining unit of the process eliminates two links of alkali washing and water washing.

Despite the advances of the above processes, there are some drawbacks. For example, in the ladder self-cooling alkylation process of Exxonmobil company, olefin and isobutane are not mixed in advance, if emulsion at the injection position of olefin is in an acid continuous phase, the olefin often generates a side reaction with acid to generate a mixed polymer, so that adjacent reaction sections are affected, and finally the whole reactor is affected; in addition, the whole energy consumption is high, the function control is complex, the operation difficulty is high, and the reliability of the system operation is influenced.

Disclosure of Invention

The invention aims to provide an industrial isooctane production system to reduce energy consumption and improve product yield and quality.

The technical scheme adopted by the invention is as follows:

an industrial isooctane production system comprises a raw material pretreatment unit, a reaction unit, a refrigeration compression unit, a refining and fractionation unit and a chemical treatment unit;

the raw material pretreatment unit comprises a feeding buffer tank (V-6101), the feeding buffer tank (V-6101) is connected to a light hydrocarbon removing tower (T-6010) through a feeding pump (P-6101A/B), and a heat exchanger (E-6101A/B) is arranged between the feeding pump (P-6101A/B) and the light hydrocarbon removing tower (T-6010); the light dydrocarbon removing tower (T-6010) is connected with a light dydrocarbon removing tower top reflux tank (V-6102) through a condenser (E-6102A/B), the bottom of the reflux tank (V-6102) is connected with a reflux pump (P-6102A/B), the outlet of the reflux pump (P-6102A/B) is divided into two pipelines, one is used as reflux to return to the top of the light dydrocarbon removing tower (T-6010), and the other is communicated with the outside of the system and is used for conveying a byproduct C3; the bottom of the light dydrocarbon removal tower (T-6010) is connected to a raw material coalescer (V-6103) through a heat exchanger (E-6101A/B), and a carbon four cooler (E-6105A/B) is also arranged between the heat exchanger (E-6101A/B) and the raw material coalescer (V-6103);

the reaction unit comprises a raw material mixer (M-6201), after mixing a carbon four raw material, circulating isobutane and a circulating refrigerant, connecting the mixture to three reactors (R-6201A/B/C) in three ways, wherein each reactor (R-6201A/B/C) is connected with an acid hydrocarbon settler (V-6202A/B/C) through an ascending pipe, the acid hydrocarbon settler (V-6202A/B/C) is provided with three outlets, namely an upper outlet, a lower outlet and a lower outlet, one lower outlet is connected to an inlet of the reactor (R-6201A/B/C) through a descending pipe, the other lower outlet is connected to a waste acid dealkylation tank (V-6301), and the upper outlet is connected to a flash tank (V-6203); the unit is also provided with a fresh acid storage tank (V-6303) for receiving fresh sulfuric acid sent from the device;

the refrigeration compression unit comprises a compressor inlet liquid separation tank (V-6204) and a refrigerant tank (V-6205), the compressor inlet liquid separation tank (V-6203) is connected with the flash tank (V-6203), the top of the compressor inlet liquid separation tank (V-6204) is connected to the refrigeration compressor (C-6201), and the refrigeration compressor (C-6201) is sequentially connected with a refrigerant air cooler (A-6201A-H) and the refrigerant tank (V-6205); the flash tank (V-6203) is provided with a middle partition plate, the upper part of the flash tank is provided with two inlets and 1 outlet, the lower part of the flash tank is provided with three outlets, one inlet of the upper part of the flash tank is connected to the upper outlet of the acid hydrocarbon settler (V-6202A/B/C), the other inlet of the flash tank is respectively connected to the bottom of the compressor inlet liquid separation tank (V-6204) and the bottom of the refrigerant tank (V-6205) through a tee joint, the outlet of the upper part of the flash tank is connected to the middle part of the compressor inlet liquid separation tank (V-6204), and one outlet of the lower part of the flash tank is connected to the raw material carbon four-feed heat exchanger (E-6201A/B/C/D; the other outlet of the lower part is connected to the feed line of the reactor (R-6201A/B/C) through a circulating refrigerant pump (P-6202A/B), and the outlet of the middle part is connected to an acid discharge tank (V-6302) through an acid discharge pump (P-6204A/B);

the refining and fractionating unit comprises a distillate acid washing tank (V-6209), the upper part of the distillate acid washing tank is connected to the upper inlet of the effluent alkali washing tank (V-6210) through an effluent alkali washing mixer (M-6203), the upper outlet of the effluent alkali washing tank (V-6210) is connected to the upper inlet of the effluent water washing tank (V-6211) through an effluent water washing mixer (M-6204), the upper outlet of the effluent water washing tank (V-6211) is connected to the middle part of an isobutane stripping tower (T-6201) through an isooctane-isobutane tower feed heat exchanger (E-6213), wherein, the lower part of the effluent alkaline washing tank (V-6210) and the lower part of the effluent water washing tank (V-6211) are respectively self-circulated by an alkaline washing circulating pump (P-6207A/B) and a water washing circulating pump (P-6208A/B); the top of the deisobutanizer (T-6201) is connected to the inlet of the tower top reflux tank (V-6212) through a deisobutanizer tower top wet air cooler (A-6202A/B/C), the outlet of the tower top reflux tank (V-6212) is divided into two paths through a deisobutanizer tower reflux pump (P-6209A/B), one path returns to the top of the deisobutanizer (T-6201), the other path is connected to a pipeline between the raw material coalescer (V-6103) and the reaction feed heat exchanger (E-6201A/B/C/D) (circulating reaction is carried out), the bottom of the deisobutanizer (T-6201) is connected to the middle part of the deisobutanizer (T-6202), the top of the deisobutanizer (T-6202) is connected to the inlet of the tower top normal butane reflux tank (V-6214) through the tower top wet air cooler (A-6203A/B), the outlet of the n-butane tower top reflux tank (V-6214) is divided into two paths by an n-butane tower reflux pump (P-6210A/B), wherein one path returns to the top of the n-butane removal tower (T-6202), and the other path leads to an n-butane product outlet area; the bottom of the de-n-butane tower (T-6202) passes through an isooctane product pump (P-6211A/B) and leads to an isooctane product outlet area after passing through an isooctane-isobutane tower feed heat exchanger (E-6213); the refining and fractionating unit is also provided with two desalted water buffer tanks 1(V-6305) and 2(V-6303) which are connected in series and are respectively connected to the bottoms of the effluent water washing tank (V-6211) and the effluent alkaline washing tank (V-6210);

the chemical treatment unit comprises a waste acid hydrocarbon removal tank (V-6301), wherein the lower outlet of the waste acid hydrocarbon removal tank is connected to an acid discharge tank (V-6302), the lower part of the acid discharge tank (V-6302) is provided with two outlets, one of the two outlets is connected to a reactor (R-6201A/B/C), the other outlet is connected to a waste acid recovery device, the upper outlet is connected to the middle part of an acid gas-containing alkaline tower (T-6301), the top part of the acid gas-containing alkaline tower (T-6301) is connected to a vent pipe, and the lower parts of the acid gas-containing alkaline tower are respectively returned to the tower through an alkaline tower circulating pump (P-; the unit is also provided with a storage tank (V-6304) for fresh acid (98% H2SO 4) to receive fresh sulfuric acid from the unit.

Further, the light dydrocarbon removing tower (T-6010) is provided with 69 layers of tower plates in total, and raw materials enter the 29 th layer of tower plate; the overhead pressure was controlled at 1.65 MPaG.

The invention has the beneficial effects that:

the system of the invention improves and optimizes the traditional process system, thereby reducing the energy consumption of the system, improving the product quality, and simultaneously improving the reliability and stability of the system operation, in particular to a reactor effluent refrigerating process, compared with the domestic existing isooctane sulfate process, the system has the obvious advantages of high yield of industrial isooctane products (improved by about 10%), high octane number (improved by about 2 units), low acid consumption (reduced by about 30%), low energy consumption (reduced by about 35%), and the like. The technology has the following characteristics:

(1) adopting a horizontal eccentric high-efficiency reactor: the reactor was equipped with a powerful agitator and internal jacket to complete the mixing and circulation of the acid hydrocarbon emulsion. The reactor is provided with a cooling tube bundle, and the heat of reaction is removed by reduced pressure evaporation of the reaction effluent. The high circulation flow rate inside the reactor is favorable to heat diffusion, so that the reaction temperature of each point can be kept uniform. The reaction material circulation isobutane and olefin are premixed and then enter the reactor, acid hydrocarbon is stirred by the impeller and circulates among the tube bundles, the acid hydrocarbon forms emulsion with a large interface by mechanical stirring, the hydrocarbon is uniformly distributed in the acid, the temperature gradient is reduced, and the side reaction is reduced. These are all beneficial to improve the yield and quality of industrial isooctane.

(2) Adopting a reaction effluent refrigeration process: the liquid-phase propane and butane in the reaction effluent are subjected to pressure reduction flash evaporation in a cooling tube bundle of the reactor to absorb the heat released by the alkylation reaction. After the reaction effluent is subjected to gas-liquid separation, the gas phase is compressed and condensed again by a compressor, and after part of propane is extracted, the gas phase is recycled to the reactor. The effluent refrigeration process allows for a high isobutane concentration in the reactor to be maintained while the amount of isobutane recycled from the deisobutanizer is minimized as compared to a closed-loop refrigerant cycle refrigeration or self-cooling process.

(3) The reaction effluent adopts an alkaline water washing process: the device adopts 12 percent NaOH for alkali cleaning removal, and compared with the traditional alkali cleaning, the device can effectively remove sulfate and remove trace acid.

(4) Product refining and fractionation unit: the product refining and fractionating unit adopts double-tower separation (3 components are separated, namely isobutane, normal butane and isooctane, 1 tower is used for separation, the number of tower plates (namely the height of the tower) is increased, a lateral line is extracted, the equipment investment and the operation difficulty are increased), firstly, isobutane in a reaction product is separated by the deisobutanizer, part of isobutane serves as reflux, and part of isobutane serves as circulating isobutane to meet the reaction requirement. And then separating n-butane from the industrial isooctane product through an n-butane removal tower, feeding the qualified industrial isooctane product at the bottom of the tower into a finished product tank, wherein the n-butane can be used as a liquefied gas product for export sales or provides a raw material for maleic anhydride.

Drawings

FIG. 1 is a feed pretreatment unit and a reaction unit of the present system;

FIG. 2 is a view of some of the components of the refrigeration compression unit, chemical treatment unit, and refining and fractionation unit of the present system;

figure 3 is the main components of the refining and fractionation unit.

Note: FIGS. 1-3 are taken together as a single drawing, showing the entire system, separated into three drawings, since the parts are not clearly visible when placed in a sheet of paper; A1-G1 in FIG. 1 correspond to A2-G2 in FIG. 2 one by one, and A3 and H1 in FIG. 2 correspond to A4 and H2 in FIG. 3, respectively.

Detailed Description

The invention relates to a 30-ten-thousand-ton/year industrial isooctane production process system, which takes olefin and isobutane in liquefied gas as raw materials, and products of the olefin and the isobutane are industrial isooctane, isobutane, normal butane, propane and the like. The product can be widely applied to the aspects of energy, chemical raw materials, fuel blenders and the like, and has wide market prospect.

An industrial isooctane production system comprises a raw material pretreatment unit, a reaction unit, a refrigeration compression unit, a refining and fractionation unit and a chemical treatment unit;

the raw material pretreatment unit comprises a feeding buffer tank (V-6101), the feeding buffer tank (V-6101) is connected to a light dydrocarbon removal tower (T-6010) through a feeding pump (P-6101A/B), the light dydrocarbon removal tower (T-6010) is provided with 69 layers of tower plates in total, and the raw material enters a 29 th layer of tower plates; the pressure at the top of the tower is controlled to be 1.65 MPaG; a heat exchanger (E-6101A/B) is arranged between the feeding pump (P-6101A/B) and the light hydrocarbon removing tower (T-6010); the raw material is pressurized by a feed pump (P-6101A/B) and then enters a light dydrocarbon removal tower (T-6010)29 layers of tower plates, the light dydrocarbon removal tower aims at separating out C3 light components in the raw material, and 69 layers of tower plates are arranged in the light dydrocarbon removal tower. The light dydrocarbon removing tower (T-6010) is connected with a light dydrocarbon removing tower top reflux tank (V-6102) through a condenser (E-6102A/B), the bottom of the reflux tank (V-6102) is connected with a reflux pump (P-6102A/B), the outlet of the reflux pump (P-6102A/B) is divided into two pipelines, one is used as reflux to return to the top of the light dydrocarbon removing tower (T-6010), and the other is communicated with the outside of the system and is used for conveying a byproduct C3; the bottom of a light dydrocarbon removal tower (T-6010) is connected to a raw material coalescer (V-6103) through a heat exchanger (E-6101A/B), a carbon four cooler (E-6105A/B) is also arranged between the heat exchanger (E-6101A/B) and the raw material coalescer (V-6103), the carbon four components of which the C3 is removed at the tower bottom firstly exchange heat with the raw material in a tank area through the heat exchanger (E-6101A/B) to heat the raw material to reduce the temperature of the raw material, and then continuously reduce the temperature (depending on cooling water) through the carbon four cooler (E-6105A/B), and then enter the raw material coalescer (V-6103) for dehydration; the raw material is connected to a reaction feed heat exchanger (E-6201A/B/C/D) through a raw material coalescer (V-6103) for further cooling and reducing the solubility of water in the raw material, and then the raw material enters a raw material filter element dehydrator (V-6206A/B/C/D) and a raw material dehydrator in sequence for further removing free water.

The reaction unit comprises a raw material mixer (M-6201), wherein after a carbon four raw material, circulating isobutane and a circulating refrigerant are mixed, the raw material mixer is connected to three reactors (R-6201A/B/C) in three ways, each reactor (R-6201A/B/C) is connected with an acid hydrocarbon settler (V-6202A/B/C) through an ascending pipe, acid-hydrocarbon emulsion which is completely reacted directly enters the acid hydrocarbon settler (V-6202A/B/C) through the ascending pipe, settlement separation of acid and hydrocarbon is carried out in the acid hydrocarbon settler, the acid hydrocarbon settler (V-6202A/B/C) is provided with three outlets which are two above and two below, one lower outlet is connected to an inlet of the reactor (R-6201A/B/C) through a descending pipe, and separated acid liquid returns to the reactor through the descending pipe for reuse, the other lower outlet is connected to a waste acid dealkylation tank (V-6301) for collecting the discharged waste acid, and the upper outlet is connected to a flash tank (V-6203), before that, the pipeline exchanges heat with a heat extraction pipe bundle in the reactor; the unit was also provided with fresh acid (98% H)₂SO₄) A storage tank (V-6303) for receiving fresh sulfuric acid from the apparatus; the tank is covered by nitrogen, so that the moisture in the air is prevented from entering the tank to dilute the acid and corrode equipment.

The reaction of the olefin in the C-cut fraction with isobutane is mainly a process for generating an isooctane fraction through an addition reaction in the presence of a sulfuric acid catalyst. After being mixed with circulating isobutane at the top of a deisobutanizer (T-6201), the carbon four fraction from the bottom of a light hydrocarbon removal tower (T-6101) is cooled to about 11 ℃ by exchanging with a reaction feed heat exchanger (E-6201A/B/C/D), then the carbon four component enters a reaction feed dehydrator (V-6201A/B), is dehydrated again (less than or equal to 10 ppm), and then is mixed with circulating refrigerant from a flash tank (V-6203) through a mixer (M-6201) to reduce the temperature to 3.0-6.0 ℃, and then is divided into three paths to enter the reactor (R-6201A/B/C) respectively. The reactor is a pressure vessel equipped with an internal circulation jacket, a heat extraction tube bundle and a stirring impeller. The olefin and isobutane in the feed are reacted in the presence of a sulfuric acid catalyst to produce technical isooctane. The acid-hydrocarbon emulsion after complete reaction directly enters an acid-hydrocarbon settler (V-6202A/B/C) through an ascending pipe, the acid and the hydrocarbon are settled and separated, and the separated acid liquid returns to the reactor for reuse through a circulating acid descending pipe. The circulation of acid in the reaction-settling system is naturally circulated by means of the specific gravity difference of materials in the ascending pipe and the descending pipe, and waste acid with the concentration of 90 percent is discharged from the acid hydrocarbon settler to a waste acid dealkylation tank (V-6301). The device is provided with 3 reactors, and is operated in parallel, namely mixed carbon is divided into three paths and enters respectively, sulfuric acid used as a catalyst is operated in series, namely supplemented fresh acid enters an acid settling tank (V-6202A), intermediate acid from the acid settling tank (V-6202A) enters an acid settling tank (V-6202B), intermediate acid from the acid settling tank (V-6202B) enters an acid settling tank (V-6202C), and 90% waste acid from the acid settling tank (V-6202C) is discharged. The three sets of reaction-settling systems can also be operated individually. After the pressure of the hydrocarbon phase separated from the acid hydrocarbon settler is reduced by a pressure control valve, the hydrocarbon phase flows through a heat extraction tube bundle in the reactor to be partially vaporized, and the heat is absorbed to take away the reaction heat. The vapor-liquid mixture enters a flash tank (V-6203). The circulating refrigerant is pumped out by a circulating refrigerant pump (P-6202A/B) and sent to a feeding line of the reactor (R-6201A/B/C) to be directly mixed with the raw material C4. The hydrocarbon gas from the flash tank vapor space is passed to a refrigeration compressor. The flash tank is provided with an acid bag, and an acid hydrocarbon interface can be observed by means of a liquid level meter of the acid bag. Normally, the acid sites of the acid package are low. When the heat-taking tube bundle in the reactor leaks, a large amount of sulfuric acid is contained in the acid bag, and an acid discharge pump (P-6204) is started to send the acid to an acid discharge tank (V-6302). 98% fresh sulfuric acid was continuously fed to the reactor.

The refrigeration compression unit comprises a compressor inlet liquid separation tank (V-6204) and a refrigerant tank (V-6205), the compressor inlet liquid separation tank (V-6203) is connected with the flash tank (V-6203), the top of the compressor inlet liquid separation tank (V-6204) is connected to the refrigeration compressor (C-6201), and the refrigeration compressor (C-6201) is sequentially connected with a refrigerant air cooler (wet air cooling A-6201A-H) and the refrigerant tank (V-6205); the flash tank (V-6203) is provided with a middle partition plate, the upper part of the flash tank is provided with two inlets and 1 outlet, the lower part of the flash tank is provided with three outlets, one inlet of the upper part of the flash tank is connected to the upper outlet of the acid hydrocarbon settler (V-6202A/B/C), the other inlet of the flash tank is respectively connected to the bottom of the compressor inlet liquid separation tank (V-6204) and the bottom of the refrigerant tank (V-6205) through a tee joint, the outlet of the upper part of the flash tank is connected to the middle part of the compressor inlet liquid separation tank (V-6204), one outlet of the lower part of the flash tank is connected to the raw material carbon four-feed heat exchanger (E-6201A/B/C/D) through a reaction effluent pump (P-6201A/B) for cold exchange, the raw material carbon four-feed heat; the other outlet at the lower part was connected to the feed line of the reactor (R-6201A/B/C) via a circulating refrigerant pump (P-6202A/B) to be directly mixed with the feed carbon four, and the outlet at the middle was connected to an acid discharge tank (V-6302) via an acid discharge pump (P-6204A/B).

The feeding temperature of the reactor is required to be 3.0-6.0 ℃, and the temperature is realized by mixing a low-temperature circulating refrigerant into the feeding of the reactor. To this end, a corresponding refrigeration system is required to meet this requirement. The equilibrium steam (hydrocarbon gas) in the gas phase space of the flash tank is collected to an outlet pipe from two sides of a baffle plate and then sequentially enters a liquid separation tank (V-6204) at the inlet of the compressor and a refrigeration compressor (C-6201). After being compressed to 0.72MPa by a compressor, the gas is condensed to 49 ℃ by a refrigerant air cooler (wet air cooling A-6201) and enters a refrigerant tank (V-6205). The liquid is decompressed under the control of flow rate and then returns to the flash tank, the temperature of the refrigerant is reduced to about minus 10 ℃ by decompression and flash evaporation, and the refrigerant is pumped by a circulating refrigerant pump (P-6202A/B) and sent to a reactor feeding mixer (M-6201) to be mixed and fed into a reaction unit for circulation.

The refining and fractionating unit comprises a distillate acid washing tank (V-6209), the upper part of the distillate acid washing tank is connected to the upper inlet of the effluent alkali washing tank (V-6210) through an effluent alkali washing mixer (M-6203), the upper outlet of the effluent alkali washing tank (V-6210) is connected to the upper inlet of the effluent water washing tank (V-6211) through an effluent water washing mixer (M-6204), the upper outlet of the effluent water washing tank (V-6211) is connected to the middle part of an isobutane stripping tower (T-6201) through an isooctane-isobutane tower feed heat exchanger (E-6213), wherein, the lower part of the effluent alkaline washing tank (V-6210) and the lower part of the effluent water washing tank (V-6211) are respectively self-circulated by an alkaline washing circulating pump (P-6207A/B) and a water washing circulating pump (P-6208A/B); the top of the deisobutanizer (T-6201) is connected to the inlet of the tower top reflux tank (V-6212) through a deisobutanizer tower top wet air cooler (A-6202A/B/C), the outlet of the tower top reflux tank (V-6212) is divided into two paths through a deisobutanizer tower reflux pump (P-6209A/B), one path returns to the top of the deisobutanizer (T-6201), the other path is connected to a pipeline between the raw material coalescer (V-6103) and the reaction feed heat exchanger (E-6201A/B/C/D) (circulating reaction is carried out), the bottom of the deisobutanizer (T-6201) is connected to the middle part of the deisobutanizer (T-6202), the top of the deisobutanizer (T-6202) is connected to the inlet of the tower top normal butane reflux tank (V-6214) through the tower top wet air cooler (A-6203A/B), the outlet of the n-butane tower top reflux tank (V-6214) is divided into two paths by an n-butane tower reflux pump (P-6210A/B), wherein one path returns to the top of the n-butane removal tower (T-6202), and the other path leads to an n-butane product outlet area; the bottom of the de-n-butane tower (T-6202) passes through an isooctane product pump (P-6211A/B) and leads to an isooctane product outlet area after passing through an isooctane-isobutane tower feed heat exchanger (E-6213); the refining and fractionating unit is also provided with two desalted water buffer tanks 1(V-6305) and 2(V-6303) which are connected in series and are respectively connected to the bottoms of the effluent water washing tank (V-6211) and the effluent alkali washing tank (V-6210).

The reaction effluent from the reaction unit contains small amounts of entrained acids and neutral sulfates formed by the reaction of olefins with sulfuric acid. If these esters are not removed, they will decompose to give SO under the high temperature conditions of the downstream deisobutanizer (T-6201)₂When water is encountered, the tower top system is seriously corroded. Therefore, the removal is needed, and the device adopts the methods of acid separation and alkali washing for removal, namely, the effluent is separated by an acid washing separation tank and then trace acid is removed by 10 percent NaOH.

The reaction distillate after heat exchange with the mixed C4 enters into an acid washing system and enters into the bottom of an effluent acid washing tank (V-6209), which can separate most of the sulfate in the reaction effluent. The separation of the effluent hydrocarbons and acid in the pickling tank reduces the acid content of the hydrocarbon effluent to 10ppm by volume.

And mixing the effluent after acid washing with circulating alkaline liquor in an effluent alkaline washing mixer (M-6203), and removing trace acid in an effluent alkaline washing tank, and hydrolyzing and removing trace sulfate carried in the effluent. The alkaline water containing sodium sulfate and sulfite is extracted from the bottom of an alkaline washing tank (V-6210) of the effluent by an alkaline washing circulating pump (P-6207A/B). According to the operation condition of the alkali washing system, fresh alkali liquor with the concentration of 10% is intermittently supplemented into the system by an alkali injection pump so as to maintain the pH value of the circulating alkali water to be 10 +/-1. The effluent from the effluent alkaline washing tank (V-6210) is mixed with desalted water through an effluent water washing mixer (M-6203), and then enters an effluent water washing tank (V-6211) for separating hydrocarbon and water.

The chemical treatment unit comprises a waste acid hydrocarbon removal tank (V-6301), wherein the lower outlet of the waste acid hydrocarbon removal tank is connected to an acid discharge tank (V-6302), the lower part of the acid discharge tank (V-6302) is provided with two outlets, one of the two outlets is connected to a reactor (R-6201A/B/C), the other outlet is connected to a waste acid recovery device, the upper outlet is connected to the middle part of an acid gas-containing alkaline tower (T-6301), the top part of the acid gas-containing alkaline tower (T-6301) is connected to a vent pipe, and the lower parts of the acid gas-containing alkaline tower are respectively returned to the tower through an alkaline tower circulating pump (P-; the unit was also provided with fresh acid (98% H)₂SO 4) storage tank (V-6304) for receiving fresh sulfuric acid from the outside of the plant. The tank is covered by nitrogen, so that the moisture in the air is prevented from entering the tank to dilute the acid and corrode equipment.

The device is provided with a waste acid dealkylation tank (V-6301) and an acid discharge tank (V-6302), and the waste acid is received from an acid package of a reaction unit acid hydrocarbon settler (V-6202A/B/C) and a flash tank (V-6203) during normal operation and is used for buffering the waste acid and separating carried hydrocarbons; receiving the emptying of the safety valve of the acid-containing system container in an accident state, and separating acid from hydrocarbon; an acid-containing effluent from an acid-containing system vessel is received during a shutdown. After hydrocarbons are separated from the waste acid in the acid discharge tank, the recovered acid-containing hydrocarbons are sent to the reaction unit by an acid-containing waste oil pump (P-6302A/B). Acid-containing oil gas from the acid discharge tank enters an acid-containing gas alkaline washing tower (T-6301) for alkaline washing neutralization, and the tower is a packed tower. And pumping the tower bottom alkali liquor alkaline washing tower circulating pump (P-6303A/B) and returning the pumped liquid into the tower for recycling.