阅读说明：本技术 双段床碳三液相加氢反应器的自动控制方法及系统 (Automatic control method and system for double-section bed carbon three-liquid phase hydrogenation reactor ) 是由 卫国宾 张立岩 汪晓菁 戚文新 于 2020-05-28 设计创作，主要内容包括：本公明公开了一种双段床碳三液相加氢反应器的自动控制方法及系统,其中,双段床碳三液相加氢反应器的自动控制方法,碳三液相加氢反应器包括一段反应器和二段反应器,所述一段反应器和二段反应器串联；所述方法包括：获取所述一段反应器的运行数据,基于所述一段反应器的运行数据调整碳三液相加氢反应器的操作条件,使所述一段反应器出口MAPD体积含量在第一设定值；获取所述二段反应器的运行数据,基于所述二段反应器的运行数据调整碳三液相加氢反应器的操作条件,使所述二段反应器出口MAPD体积含量在第二设定值。本发明的方法及系统可达到提高丙烯选择性的目的。(The invention discloses an automatic control method and system of a double-section bed carbon three-liquid-phase hydrogenation reactor, wherein the double-section bed carbon three-liquid-phase hydrogenation reactor comprises a first-section reactor and a second-section reactor which are connected in series; the method comprises the following steps: acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of a carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to enable the volume content of MAPD at the outlet of the first-stage reactor to be a first set value; and acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-three-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to enable the MAPD volume content at the outlet of the second-stage reactor to be at a second set value. The method and the system can achieve the aim of improving the selectivity of the propylene.)

1. The automatic control method of the double-section bed carbon three-liquid-phase hydrogenation reactor is characterized in that the carbon three-liquid-phase hydrogenation reactor comprises a first-section reactor and a second-section reactor, wherein the first-section reactor and the second-section reactor are connected in series;

the method comprises the following steps:

acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of a carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to enable the volume content of MAPD at the outlet of the first-stage reactor to be a first set value;

and acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-three-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to enable the MAPD volume content at the outlet of the second-stage reactor to be at a second set value.

2. The method of automatically controlling a two-stage carbon three-liquid phase hydrogenation reactor of claim 1, wherein said operational data comprises:

the method comprises the following steps of material temperature at the inlet and outlet of a first-stage reactor and a second-stage reactor, catalyst bed temperature of the first-stage reactor and the second-stage reactor, pressure of a carbon three-liquid-phase hydrogenation reactor, material flow at the inlet of the carbon three-liquid-phase hydrogenation reactor, MAPD concentration at the inlet of the first-stage reactor and the second-stage reactor, hydrogen distribution flow and concentration of the first-stage reactor and the second-stage reactor, the molar ratio of hydrogen distribution of the first-stage reactor to MAPD at the inlet of the first-stage reactor, the molar ratio of hydrogen distribution of the second-stage reactor to MAPD at the inlet of the second-stage reactor and MAPD concentration at the outlet of the first-stage reactor and the second-stage reactor.

3. The method of claim 1, wherein the adjusting a section of operating parameters of the operating conditions of the carbon-liquid phase hydrogenation reactor based on the operating data of the section of reactor comprises the inlet material temperature of the section of reactor and the section of hydrogen-acetylene ratio:

the acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to make the volume content of MAPD at the outlet of the first-stage reactor be at a first set value includes:

when the MAPD volume content at the outlet of the first-stage reactor is at a first set value, not adjusting a first-stage operating parameter;

when the MAPD volume content at the outlet of the first-stage reactor is less than the lower limit of a first set value, reducing a first-stage operating parameter;

increasing a stage operating parameter when the volumetric level of MAPD at the stage reactor outlet is greater than the upper limit of the first set point.

4. The automatic control method for a two-stage carbon three-liquid phase hydrogenation reactor according to claim 3, wherein the lowering of the one-stage operating parameters is performed by preferentially lowering the inlet material temperature of the one-stage reactor;

and/or

And preferentially increasing one-stage high-hydrogen alkyne ratio in the increasing one-stage operation parameters.

5. The automatic control method of a double-stage carbon three-liquid phase hydrogenation reactor according to claim 3, characterized in that the inlet material temperature of the first-stage reactor is adjusted within the range of 25-60 ℃, preferably 30-45 ℃;

and/or

The adjusting speed range of the inlet material temperature of the first-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

and/or

The adjustment range of the one-stage hydrogen alkyne ratio is 0.5-2.0, and preferably 0.8-1.5;

and/or

The adjustment rate of the one-stage alkyne ratio is in the range of 0.04-0.6/hour, preferably 0.08-0.4/hour.

6. The method of claim 1, wherein the adjusting of the second stage operating parameters of the operating conditions of the carbon-liquid phase hydrogenation reactor based on the operating data of the second stage reactor comprises the inlet material temperature and the second stage hydrogen to acetylene ratio of the second stage reactor:

the acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to make the volume content of MAPD at the outlet of the second-stage reactor at a second set value comprises:

when the MAPD volume content at the outlet of the second-stage reactor is at a second set value, not adjusting second-stage operation parameters;

when the MAPD volume content at the outlet of the second-stage reactor is less than the lower limit of a second set value, reducing second-stage operation parameters;

and when the volume content of MAPD at the outlet of the second-stage reactor is more than the upper limit of a second set value, raising the second-stage operation parameter.

7. The automatic control method for a two-stage bed carbon three-liquid phase hydrogenation reactor according to claim 6, wherein the lowering of the second-stage operating parameters preferentially lowers the inlet material temperature of the second-stage reactor;

and/or

The second-stage hydrogen alkyne ratio is preferentially increased in the increasing of the second-stage operation parameters.

8. The automatic control method of a two-stage bed carbon three-liquid phase hydrogenation reactor according to claim 6, characterized in that the inlet material temperature of the two-stage reactor is adjusted within the range of 25-60 ℃, preferably 30-45 ℃;

and/or

The adjusting rate range of the inlet material temperature of the second-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

and/or

The adjustment range of the two-stage hydrogen alkyne ratio is 0.8-4.0, preferably 1.4-2.0;

and/or

The adjustment rate of the two-stage alkyne ratio is in the range of 0.01-0.4/hr, preferably 0.04-0.2/hr.

9. The automatic control method of a two-stage bed carbon three-liquid phase hydrogenation reactor according to claim 1, wherein the first set value is N ± 500ppm, preferably N ± 200 ppm;

the second set point is M. + -.100 ppm, preferably M. + -.25 ppm.

10. The automatic control method for a two-stage carbon three-liquid phase hydrogenation reactor as claimed in claim 9, wherein the value range of N is 5000-12000ppm, preferably 7000-10000 ppm;

the value range of M is 100-1000ppm, preferably 200-500 ppm.

11. The automatic control system of the double-section bed carbon three-liquid phase hydrogenation reactor is characterized in that the carbon three-liquid phase hydrogenation reactor comprises a first-section reactor, a second-section reactor and a controller, wherein the first-section reactor and the second-section reactor are connected in series, a heat exchanger is arranged between the first-section reactor and the second-section reactor, and hydrogen injection pipelines are arranged at the inlets of the first-section reactor and the second-section reactor;

the controller for controlling the primary and secondary reactors by performing the method of any one of claims 1 to 10.

12. The automatic control system of a two-stage bed carbon three-liquid phase hydrogenation reactor according to claim 11, wherein the controller comprises a one-stage controller and a two-stage controller;

the first-stage controller is used for controlling the first-stage reactor, and the second-stage controller is used for controlling the second-stage reactor.

Technical Field

The invention belongs to the field of petrochemical industry, and particularly relates to an automatic control method and system for a double-stage bed carbon three-liquid-phase hydrogenation reactor.

Background

Ethylene technology is the leading technology of petrochemical industry, and the ethylene technology level is regarded as an important mark for measuring the development level of the petrochemical industry in China. Trienes (ethylene, propylene, butadiene) produced by an ethylene cracking device are basic raw materials of petrochemical industry, and the high and low yield of the trienes is a main mark for measuring the development level of the national petrochemical industry.

After the liquid hydrocarbon raw materials such as naphtha and the like in the ethylene cracking device are cracked and separated by steam, the carbon three-fraction contains propylene, propane and a small amount of Methylacetylene (MA) and Propadiene (PD) (the methylacetylene and the propadiene are abbreviated as MAPD), and the MAPD content is about 1-5 percent (volume). In propylene polymerization, MAPD reduces the activity of polypropylene catalysts, affecting the product quality of polymer grade propylene. To remove MAPD from the carbon trisection, catalytic selective hydrogenation and solvent absorption methods are currently used in the industry to remove MAPD. The carbon three liquid phase catalytic hydrogenation method has simple process flow and no environmental pollution, so the application of the catalytic hydrogenation method is increasingly common.

The carbon-three liquid phase hydrogenation reactor unit is an important device of a propylene unit recovery system, and selectively hydrogenates MAPD in the carbon-three fraction to propylene under the action of a catalyst. MAPD, if hydrogenated excessively, will produce propane, oligomers and polymers, resulting in loss of propylene; if the hydrogenation effect of MAPD is not good, the concentration of MAPD at the outlet of the reactor is not controlled in the index requirement range, which causes the unqualified product of propylene and influences the production of downstream devices, so the purity and yield of the propylene product are directly influenced by the operation quality of the hydrogenation reactor.

The carbon three liquid phase hydrogenation catalyst generally adopts transition metals such as palladium, nickel and the like as active components, reaction thermodynamic parameters, surface adsorption and desorption reaction rates and process sensitivity of different catalysts are different, and the optimal performance of the catalyst can be ensured by targeted adjustment and optimization.

At present, the production control of the carbon-liquid phase hydrogenation reactor is generally manually regulated and controlled, and technicians manually regulate and control related parameters. Due to the long cracking and separating flow, complex process and limited labor, the carbon-liquid phase hydrogenation reactor cannot be monitored in real time and adjusted and optimized in an expert level. When unstable conditions such as material composition, pressure, temperature, flow, hydrogen fluctuation and the like occur in a carbon-three hydrogenation system, the stability recovery is very slow by only depending on the liquid phase hydrogenation system, and the superposition phenomenon generated by multiple fluctuations makes the system in a metastable state for a long time, so that acetylene leakage at the outlet of a reactor and excessive hydrogenation of propylene are easy to cause, and the yield of the propylene product and the separation effect of a rectifying tower are influenced.

At present, most of operations of the carbon-three-liquid phase hydrogenation reactor adopt a manual experience and manual regulation method, so that the MAPD concentration at the outlet of the carbon-three-liquid phase hydrogenation reactor is too high or too low, and the propylene selectivity is poor.

Disclosure of Invention

In view of this, the present invention provides an automatic control method and system for a two-stage bed carbon three-liquid phase hydrogenation reactor, which at least solve the problem of poor selectivity of propylene in the prior art.

In a first aspect, the invention provides an automatic control method for a double-section bed carbon three-liquid-phase hydrogenation reactor, wherein the carbon three-liquid-phase hydrogenation reactor comprises a first-section reactor and a second-section reactor, and the first-section reactor and the second-section reactor are connected in series;

the method comprises the following steps:

acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of a carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to enable the volume content of MAPD at the outlet of the first-stage reactor to be a first set value;

and acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-three-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to enable the MAPD volume content at the outlet of the second-stage reactor to be at a second set value.

Optionally, the operation data includes:

the method comprises the following steps of material temperature at the inlet and outlet of a first-stage reactor and a second-stage reactor, catalyst bed temperature of the first-stage reactor and the second-stage reactor, pressure of a carbon three-liquid-phase hydrogenation reactor, material flow at the inlet of the carbon three-liquid-phase hydrogenation reactor, MAPD concentration at the inlet of the first-stage reactor and the second-stage reactor, hydrogen distribution flow and concentration of the first-stage reactor and the second-stage reactor, the molar ratio of hydrogen distribution of the first-stage reactor to MAPD at the inlet of the first-stage reactor, the molar ratio of hydrogen distribution of the second-stage reactor to MAPD at the inlet of the second-stage reactor and MAPD concentration at the outlet of the first-stage reactor and the second-stage reactor.

Optionally, the adjusting a first-stage operating parameter of the operating conditions of the carbon-three-liquid phase hydrogenation reactor based on the operating data of the first-stage reactor includes an inlet material temperature of the first-stage reactor and a first-stage hydrogen-acetylene ratio:

the acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to make the volume content of MAPD at the outlet of the first-stage reactor be at a first set value includes:

when the MAPD volume content at the outlet of the first-stage reactor is at a first set value, not adjusting a first-stage operating parameter;

when the MAPD volume content at the outlet of the first-stage reactor is less than the lower limit of a first set value, reducing a first-stage operating parameter;

increasing a stage operating parameter when the volumetric level of MAPD at the stage reactor outlet is greater than the upper limit of the first set point.

Optionally, the temperature of the material at the inlet of the first-stage reactor is preferentially reduced in the first-stage operation parameter reduction;

and/or

And preferentially increasing one-stage high-hydrogen alkyne ratio in the increasing one-stage operation parameters.

Optionally, the adjustment range of the inlet material temperature of the first-stage reactor is 25-60 ℃, and preferably 30-45 ℃;

and/or

The adjusting speed range of the inlet material temperature of the first-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

and/or

The adjustment range of the one-stage hydrogen alkyne ratio is 0.5-2.0, and preferably 0.8-1.5;

and/or

The adjustment rate of the one-stage alkyne ratio is in the range of 0.04-0.6/hour, preferably 0.08-0.4/hour.

Optionally, the second-stage operation parameters in the operation conditions of the carbon-three-liquid phase hydrogenation reactor are adjusted based on the operation data of the second-stage reactor, including the inlet material temperature and the second-stage alkyne ratio of the second-stage reactor:

the acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to make the volume content of MAPD at the outlet of the second-stage reactor at a second set value comprises:

when the MAPD volume content at the outlet of the second-stage reactor is at a second set value, not adjusting second-stage operation parameters;

when the MAPD volume content at the outlet of the second-stage reactor is less than the lower limit of a second set value, reducing second-stage operation parameters;

and when the volume content of MAPD at the outlet of the second-stage reactor is more than the upper limit of a second set value, raising the second-stage operation parameter.

Optionally, the inlet material temperature of the secondary reactor is preferentially reduced in the reduction of the secondary operation parameters;

and/or

The second-stage hydrogen alkyne ratio is preferentially increased in the increasing of the second-stage operation parameters.

Optionally, the adjustment range of the inlet material temperature of the secondary reactor is 25-60 ℃, and preferably 30-45 ℃;

and/or

The adjusting rate range of the inlet material temperature of the second-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

and/or

The adjustment range of the two-stage hydrogen alkyne ratio is 0.8-4.0, preferably 1.4-2.0;

and/or

The adjustment rate of the two-stage alkyne ratio is in the range of 0.01-0.4/hr, preferably 0.04-0.2/hr.

Optionally, the first set value is N ± 500ppm, preferably N ± 200 ppm;

the second set point is M. + -.100 ppm, preferably M. + -.25 ppm.

Optionally, the value range of N is 5000-;

the value range of M is 100-1000ppm, preferably 200-500 ppm.

In a second aspect, the invention provides an automatic control system of a double-section bed carbon three-liquid phase hydrogenation reactor, wherein the carbon three-liquid phase hydrogenation reactor comprises a first-section reactor, a second-section reactor and a controller, the first-section reactor and the second-section reactor are connected in series, a heat exchanger is arranged between the first-section reactor and the second-section reactor, and hydrogen injection pipelines are arranged at inlets of the first-section reactor and the second-section reactor;

the controller is configured to control the primary reactor and the secondary reactor by performing the method of any one of the first aspect.

Optionally, the controller includes a first-stage controller and a second-stage controller;

the first-stage controller is used for controlling the first-stage reactor, and the second-stage controller is used for controlling the second-stage reactor.

The operation data of the first-stage reactor and the operation data of the second-stage reactor are used for adjusting the operation conditions of the carbon three-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor and the operation data of the second-stage reactor, so that the MAPD volume content at the outlet of the first-stage reactor is at a first set value, and the MAPD volume content at the outlet of the second-stage reactor is at a second set value. Automatically maintaining and adjusting various operating parameters in the carbon-three liquid phase hydrogenation reactor, so that the MAPD content is stably hydrogenated within a certain range, and the optimal hydrogenation efficiency and propylene selectivity of the carbon-three liquid phase hydrogenation reactor are obtained. .

Drawings

Exemplary embodiments of the present invention will be described in more detail by referring to the accompanying drawings.

FIG. 1 shows a flow diagram of a method for the automatic control of a two-stage bed carbon three-liquid phase hydrogenation reactor according to one embodiment of the present invention;

FIG. 2 shows a diagram of an example of the structure of a two-stage bed carbon three-liquid phase hydrogenation reactor according to one embodiment of the present invention;

FIG. 3 illustrates a functional block diagram of an automatic control apparatus for a carbon three liquid phase hydrogenation reactor in accordance with an embodiment of the present invention;

FIGS. 4a to 4f are schematic diagrams illustrating changes in the first and second stage process conditions of a carbon three liquid phase hydrogenation reactor using an automated control method for a two stage bed carbon three liquid phase hydrogenation reactor according to an embodiment of the present invention;

wherein: 1-first stage reactor; 2-a two-stage reactor; 3-a heat exchanger; 4-a circulating pump; 5-pressure tank.

Detailed Description

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

The present invention will be further described with reference to the following examples, but the scope of the present invention is not limited to these examples.

The first embodiment is as follows:

as shown in figure 1 of the drawings, in which,

an automatic control method of a double-section bed carbon three-liquid-phase hydrogenation reactor comprises the steps that the carbon three-liquid-phase hydrogenation reactor comprises a first-section reactor and a second-section reactor, and the first-section reactor and the second-section reactor are connected in series;

the method comprises the following steps:

step S101: acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of a carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to enable the volume content of MAPD at the outlet of the first-stage reactor to be a first set value;

optionally, the first set value is N ± 500ppm, preferably N ± 200 ppm; the value range of N is 5000-12000ppm, preferably 7000-10000 ppm. Specifically, N may be 5000, 6000, 7000, 8000, 9000, 10000, 11000, or 12000.

Step S102: and acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-three-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to enable the MAPD volume content at the outlet of the second-stage reactor to be at a second set value.

The second set point is M. + -.100 ppm, preferably M. + -.25 ppm. The value range of M is 100-1000ppm, preferably 200-500 ppm.

A specific M may be 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000.

Optionally, the operation data includes:

the method comprises the following steps of material temperature at the inlet and outlet of a first-stage reactor and a second-stage reactor, catalyst bed temperature of the first-stage reactor and the second-stage reactor, pressure of a carbon three-liquid-phase hydrogenation reactor, material flow at the inlet of the carbon three-liquid-phase hydrogenation reactor, MAPD concentration at the inlet of the first-stage reactor and the second-stage reactor, hydrogen distribution flow and concentration of the first-stage reactor and the second-stage reactor, the molar ratio of hydrogen distribution of the first-stage reactor to MAPD at the inlet of the first-stage reactor, the molar ratio of hydrogen distribution of the second-stage reactor to MAPD at the inlet of the second-stage reactor and MAPD concentration at the outlet of the first-stage reactor and the second-stage reactor. The molar ratio of the hydrogen to be added to the first-stage reactor to the MAPD at the inlet of the first-stage reactor is referred to as the first-stage alkyne ratio for short, and the molar ratio of the hydrogen to be added to the second-stage reactor to the MAPD at the inlet of the second-stage reactor is referred to as the second-stage alkyne ratio for short.

Optionally, the adjusting a first-stage operating parameter of the operating conditions of the carbon-three-liquid phase hydrogenation reactor based on the operating data of the first-stage reactor includes an inlet material temperature of the first-stage reactor and a first-stage hydrogen-acetylene ratio:

the acquiring the operation data of the first-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the first-stage reactor to make the volume content of MAPD at the outlet of the first-stage reactor be at a first set value includes:

when the MAPD volume content at the outlet of the first-stage reactor is at a first set value, not adjusting a first-stage operating parameter;

when the MAPD volume content at the outlet of the first-stage reactor is less than the lower limit of a first set value, reducing a first-stage operating parameter;

increasing a stage operating parameter when the volumetric level of MAPD at the stage reactor outlet is greater than the upper limit of the first set point.

Optionally, the temperature of the material at the inlet of the first-stage reactor is preferentially reduced in the first-stage operation parameter reduction;

and preferentially increasing one-stage high-hydrogen alkyne ratio in the increasing one-stage operation parameters.

When the MAPD volume at the outlet of the first-stage reactor is within N +/-500 ppm, preferably within N +/-200 ppm, the operating parameters of the first-stage reactor are not adjusted;

when the volume of the MAPD at the outlet of the first-stage reactor is less than N-500ppm, preferably N-200ppm, reducing the temperature of the material at the inlet of the first-stage reactor and the hydrogen-acetylene ratio of the first stage reactor, and preferentially reducing the temperature of the material at the inlet of the first-stage reactor until the volume of the MAPD at the outlet of the first-stage reactor is within N +/-500 ppm, preferably N +/-200 ppm;

when the MAPD volume at the outlet of the first-stage reactor is more than N +500ppm, preferably N +200ppm, the inlet material temperature of the first-stage reactor and the first-stage hydrogen-alkyne ratio are increased, and the first-stage hydrogen-alkyne ratio is preferentially increased until the MAPD volume at the outlet of the first-stage reactor is within N +/-500 ppm, preferably within N +/-200 ppm.

Optionally, the adjustment range of the inlet material temperature of the first-stage reactor is 25-60 ℃, and preferably 30-45 ℃;

the inlet material temperature of the first stage reactor may be 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C, 55 deg.C or 60 deg.C.

The adjusting speed range of the inlet material temperature of the first-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

the rate of adjustment of the inlet material temperature of a particular stage reactor may be: 0.5 deg.C/hr, 1.0 deg.C/hr, 1.5 deg.C/hr, 2.0 deg.C/hr, 2.5 deg.C/hr, 3.0 deg.C/hr, 3.5 deg.C/hr, 4.0 deg.C/hr, 5.5 deg.C/hr, 6.0 deg.C/hr, 7.5 deg.C/hr, or 8.0 deg.C/hr.

The adjustment range of the one-stage hydrogen alkyne ratio is 0.5-2.0, and preferably 0.8-1.5;

the one-stage hydroacetylene ratio may be 0.5, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0.

The adjustment rate of the one-stage alkyne ratio is in the range of 0.04-0.6/hour, preferably 0.08-0.4/hour.

The specific one-stage alkyne ratio may be adjusted at a rate of 0.04/hr, 0.06/hr, 0.08/hr, 0.1/hr, 0.14/hr, 0.28/hr, 0.34/hr, 0.4/hr, 0.45/hr, 0.55/hr or 0.6/hr.

Optionally, the second-stage operation parameters in the operation conditions of the carbon-three-liquid phase hydrogenation reactor are adjusted based on the operation data of the second-stage reactor, including the inlet material temperature and the second-stage alkyne ratio of the second-stage reactor:

the acquiring the operation data of the second-stage reactor, and adjusting the operation conditions of the carbon-liquid phase hydrogenation reactor based on the operation data of the second-stage reactor to make the volume content of MAPD at the outlet of the second-stage reactor at a second set value comprises:

when the MAPD volume content at the outlet of the second-stage reactor is at a second set value, not adjusting second-stage operation parameters;

when the MAPD volume content at the outlet of the second-stage reactor is less than the lower limit of a second set value, reducing second-stage operation parameters;

and when the volume content of MAPD at the outlet of the second-stage reactor is more than the upper limit of a second set value, raising the second-stage operation parameter.

Optionally, the inlet material temperature of the secondary reactor is preferentially reduced in the reduction of the secondary operation parameters;

the second-stage hydrogen alkyne ratio is preferentially increased in the increasing of the second-stage operation parameters.

When the MAPD volume at the outlet of the second-stage reactor is within a set value of M +/-100 ppm, preferably M +/-25 ppm, the operating parameters of the first-stage reactor are not adjusted;

when the volume of the MAPD at the outlet of the second-stage reactor is less than a set value M-100ppm, preferably M-25ppm, reducing the inlet material temperature and the second-stage hydrogen-acetylene ratio of the second-stage reactor, and preferentially reducing the inlet material temperature of the second-stage reactor until the volume of the MAPD at the outlet of the second-stage reactor is within a set value M +/-100 ppm, preferably within a range of M +/-25 ppm;

and when the MAPD volume at the outlet of the second-stage reactor is greater than the set value M +100ppm, preferably M +25ppm, increasing the inlet material temperature and the second-stage hydrogen-alkyne ratio of the second-stage reactor, and preferentially increasing the second-stage hydrogen-alkyne ratio until the MAPD volume at the outlet of the second-stage reactor is within the set value M +/-100 ppm, preferably M +/-25 ppm.

Optionally, the adjustment range of the inlet material temperature of the secondary reactor is 25-60 ℃, and preferably 30-45 ℃;

the inlet material temperature of the second stage reactor may be 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C, 55 deg.C or 60 deg.C.

The adjusting rate range of the inlet material temperature of the second-stage reactor is 0.5-8.0 ℃/hour, preferably 1.0-4.0 ℃/hour;

the rate of adjustment of the inlet feed temperature to a particular two-stage reactor may be: 0.5 deg.C/hr, 1.0 deg.C/hr, 1.5 deg.C/hr, 2.0 deg.C/hr, 2.5 deg.C/hr, 3.0 deg.C/hr, 3.5 deg.C/hr, 4.0 deg.C/hr, 5.5 deg.C/hr, 6.0 deg.C/hr, 7.5 deg.C/hr, or 8.0 deg.C/hr.

The adjustment range of the two-stage hydrogen alkyne ratio is 0.8-4.0, preferably 1.4-2.0;

the di-hydrine ratio may be 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0.

The adjustment rate of the two-stage alkyne ratio is in the range of 0.01-0.4/hr, preferably 0.04-0.2/hr.

The rate of adjustment of the two-stage hydroacetylene ratio may be 0.01/hr, 0.02/hr, 0.04/hr, 0.06/hr, 0.08/hr, 0.1/hr, 0.14/hr, 0.2/hr, 0.28/hr, 0.34/hr, or 0.4/hr.

Example two:

an automatic control system of a double-section bed carbon three-liquid phase hydrogenation reactor is shown in figure 2, and the carbon three-liquid phase hydrogenation reactor comprises a first-section reactor, a second-section reactor and a controller, wherein the first-section reactor and the second-section reactor are connected in series, a heat exchanger is arranged between the first-section reactor and the second-section reactor, and hydrogen injection pipelines are arranged at the inlets of the first-section reactor and the second-section reactor;

the controller is configured to control the primary reactor and the secondary reactor by performing the method of any one of the first aspect.

Optionally, the controller includes a first-stage controller and a second-stage controller;

the first-stage controller is used for controlling the first-stage reactor, and the second-stage controller is used for controlling the second-stage reactor.

The carbon three-liquid phase hydrogenation reactor process adopts a series design of two fixed bed reactors, in the double-section bed carbon three-liquid phase hydrogenation reactor process, a heat exchanger is arranged between two reactor sections, and a hydrogen injection pipeline is respectively arranged at one section and the other section, so that accurate control is realized according to the inlet material temperature and the hydrogen alkyne ratio operation requirement of each section, the hydrogenation efficiency of the catalyst is improved, and the optimal propylene selectivity is obtained.

A double controller is introduced into a control system of a double-section bed carbon three-liquid-phase hydrogenation reactor and is divided into a first-section controller and a second-section controller. The first-stage controller and the second-stage controller are both positioned in a distributed control system of the carbon-liquid phase hydrogenation reactor, namely a DCS (distributed control system) or a server connected with the DCS. A control logic program in a segment of controller collects the volume of MAPD at the outlet of a segment of reactor, and automatically collects analysis data and stores the analysis data in a fixed memory unit; and a control logic program in the two-stage controller collects the MAPD volume in the final hydrogenation product at the outlet of the two-stage reactor and stores the automatically collected and analyzed result data in a fixed memory unit.

The control logic program in the first segment of controller automatically maintains the inlet material temperature and the first segment hydrogen acetylene ratio of the first segment reactor according to the monitored height and the change trend of the MAPD volume in the first segment carbon three hydrogenation product, and automatically realizes the stable operation of the segmented hydrogenation of the carbon three liquid phase hydrogenation reactor; and a control logic program in the two-stage controller automatically maintains and adjusts the inlet material temperature and the two-stage hydrogen alkyne ratio of the two-stage carbon three-liquid phase hydrogenation reactor according to the monitored volume content and the variation trend of MAPD at the outlet of the two-stage carbon three-liquid phase hydrogenation reactor, and automatically realizes the stable control of the carbon three-liquid phase hydrogenation reactor.

The main control variables of the control logic programs of all the controllers are the inlet material temperature of the first-stage reactor, the first-stage hydrogen alkyne ratio, the inlet material temperature of the second-stage reactor and the second-stage hydrogen alkyne ratio, and the main regulating variables are the inlet material temperature of the first-stage reactor, the first-stage hydrogen alkyne ratio, the inlet material temperature of the second-stage reactor and the second-stage hydrogen alkyne ratio.

In the control logic program of the carbon-three-liquid phase hydrogenation reactor, the regulation principle is as follows:

when the MAPD volume at the outlet of the first-stage reactor is less than a set value N-500ppm, preferably N-200ppm, reducing the material temperature at the inlet of the first-stage reactor and the hydrogen-acetylene ratio of the first stage, preferentially reducing the material temperature at the inlet of the first-stage reactor, and then adjusting the hydrogen-acetylene ratio of the first stage; when the MAPD volume at the outlet of the first-stage reactor is more than the set value of N +500ppm, preferably N +200ppm, the material temperature at the inlet of the first-stage reactor and the hydrogen-acetylene ratio of the first stage are increased, the hydrogen-acetylene ratio of the first stage is preferentially increased, and then the material temperature at the inlet of the first-stage reactor is adjusted. And a section of control logic program of the carbon-three-liquid phase hydrogenation reactor automatically adjusts the material temperature at the inlet of a section of reactor and the hydrogen-acetylene ratio of the section of reactor in the carbon-three-liquid phase hydrogenation reactor according to MAPD volume analysis data at the outlet of the section of reactor. When the volume of the MAPD at the outlet of one stage of the reactor exceeds the upper and lower limits, simultaneous adjustment of two operating parameters can be used, the rate of adjustment being at the lower limit of the adjustable range.

When the MAPD volume at the outlet of the second-stage reactor is less than a set value M-100ppm, preferably M-25ppm, reducing the material temperature at the inlet of the second-stage reactor and the second-stage hydrogen-alkyne ratio, preferentially reducing the material temperature at the inlet of the second-stage reactor, and then adjusting the second-stage hydrogen-alkyne ratio; and when the MAPD volume is greater than the set value M +100ppm, preferably M +25ppm, raising the material temperature at the inlet of the second-stage reactor and the second-stage hydrogen-alkyne ratio, preferably raising the second-stage hydrogen-alkyne ratio, and then adjusting the material temperature at the inlet of the second-stage reactor. And the control logic program of the carbon-three-liquid phase hydrogenation reactor automatically adjusts the hydrogen-alkyne ratio of the carbon-three-liquid phase hydrogenation reactor according to the analysis data of the MAPD volume at the outlet of the reactor.

In the process of adjusting various control variables of hydrogenation by a control logic program of the carbon-three liquid phase hydrogenation reactor, the adjustment ranges of the inlet material temperatures of the first stage reactor and the second stage reactor of the carbon-three hydrogenation reactor are both 25-60 ℃, and the preferred temperatures are both 30-45 ℃; the adjustment range of the first-stage hydrogen alkyne ratio of the carbon-three liquid phase hydrogenation reactor is 0.5-2.0, preferably 0.8-1.5; the adjustment range of the two-stage hydrogen alkyne ratio is 0.8-4.0, preferably 1.4-2.0; the adjustment range of the inlet material pressure of the carbon three-liquid phase hydrogenation reactor is 1.0-3.0MPa, and preferably 1.7-2.7 MPa. If an operating parameter reaches an upper limit, the parameter is kept unchanged, and another operating variable is adjusted. And if the inlet material temperature and the hydrogen acetylene ratio of the first-stage reactor and the second-stage reactor and the inlet material pressure of the reactor reach the upper limit and cannot meet the MAPD volume requirement of the first-stage outlet and the second-stage outlet of the reactor, automatically switching the operation mode into a manual mode and giving an alarm.

In the automatic control process of the carbon-three liquid phase hydrogenation reactor process, the adjustment rate range of the temperature of the material at the first section inlet of the carbon-three hydrogenation reactor is generally 0.5-8.0 ℃/hour, and preferably 1.0-4.0 ℃/hour; the adjustment rate of the one-stage alkyne ratio is in the range of 0.04 to 0.6/hr, preferably 0.08 to 0.4/hr. Simultaneous adjustment of two operating parameters can be used in the temperature range corresponding to a single stage reactor outlet MAPD volume below N-500ppm, preferably N-200ppm and above N +500ppm, preferably N +200ppm, the rate amplitude of adjustment typically being the lower end of the adjustable rate range. The volume of the primary reactor outlet MAPD is in the range of N + -500ppm, preferably N + -200ppm, and no adjustments are usually made to the operation in order to maintain the smoothness of the production operation.

In the automatic control process of the carbon-three liquid phase hydrogenation reactor, the adjustment rate range of the material temperature at the inlet of the second-stage reactor of the carbon-three hydrogenation reactor is generally 0.5-8.0 ℃/hour, and preferably 1.0-4.0 ℃/hour; the rate of adjustment of the two-stage alkyne ratio is in the range of 0.01 to 0.4/hour, preferably 0.04 to 0.2/hour. When the MAPD volume at the outlet of the two-stage reactor is lower than M-100ppm, preferably M-25ppm or higher than M +100ppm, preferably M +25ppm, the amplitude of the rate of adjustment is generally controlled within the range of the rate of adjustment. If the two-stage reactor MAPD volume lies between M + -100ppm, preferably M + -25ppm, no adjustments are usually made to the operation in order to maintain the smoothness of the production operation.

The automatic control of the double-section bed carbon three-liquid phase hydrogenation reactor is divided into two steps: a program initialization phase and an automatic control phase. The execution sequence of the automatic control program is as follows:

1. program initialization phase

After the program is started, internal variables such as the pressure of a carbon three-liquid phase hydrogenation reactor of a double-stage bed, the hydrogen-acetylene ratio of each stage, the inlet material temperature and the like are initialized, and a data signal of MAPD concentration at the outlet of each stage of reactor is automatically identified.

And confirming that all field operations are executed by an operator, inputting normal field analysis data, and preparing to enter an automatic control stage, wherein if the field analysis data are not confirmed, the program is in a waiting state until all the field analysis data are confirmed. And (4) assigning values to the MAPD concentrations N and M at the outlet of the second-stage reactor by clicking and confirming by an operator, and then entering an automatic control stage.

2. Self-control phase

After entering the dynamic control program, the control logic program judges whether each control variable in the hydrogenation reactor needs to be adjusted or not by acquiring field data and input MAPD concentration data of each section of reactor outlet according to a DCS system of the carbon-three-liquid phase hydrogenation reactor and judging every 1-1800 seconds according to a judgment principle, thereby realizing the automatic control of each parameter in the process production process of the carbon-three-liquid phase hydrogenation reactor. The shorter the time interval for adjusting the parameters, the better, but at the same time, the feedback time for adjusting the control variable signal and the time interval for analyzing the data are taken into account.

The automatic control system of the double-section bed carbon-three-liquid phase hydrogenation reactor is applied to the double-section bed carbon-three hydrogenation reactor process of an olefin plant, and the process flow is shown in figure 2 in detail. A controller connected to the OPC server of the original system is added outside the DCS system, as shown in fig. 3, to adjust the process conditions of the carbon hydrogenation reactor, and provide the adjustment target to the DCS system in real time, so as to realize automatic control of the carbon hydrogenation reactor.

Firstly, assigning the MAPD volume N of the outlet of a first-stage reactor of a first-stage controller to be 9000ppm, wherein the lower limit is 8500ppm, the upper limit is 9500ppm, and the controller can regulate and control the fluctuation of the MAPD at the outlet of the carbon three-liquid phase hydrogenation reactor within the range of 8500-; the MAPD concentration M of the outlet of the second-stage reactor of the two-stage controller is assigned to 125ppm, the lower limit is 100ppm, the upper limit is 150ppm, the controller can regulate and control the fluctuation of the MAPD of the outlet of the carbon three-liquid phase hydrogenation reactor within the range of 100-150ppm, as shown in fig. 4a to 4f, and each-stage online control unit automatically controls the inlet material temperature and the hydrogen acetylene ratio of each-stage hydrogenation reactor to adjust in real time. The overall selectivity of the two-stage carbon-three hydrogenation reactor can be increased to 67%.

Comparative example:

an olefin plant producing 45 million tons of ethylene every year has 10 cracking furnaces, and can process various cracking raw materials from ethane to hydrogenation tail oil, and produce 22 million tons of propylene every year. The separation process of the plant adopts a sequential separation flow, a carbon-three-liquid phase hydrogenation reactor is positioned between a hot zone depropanizing tower and a propylene rectifying tower, the carbon-three fraction obtained from the top of the high-pressure depropanizing tower is subjected to heat exchange by a cooler (or a preheater) to reach a required temperature, is subjected to pressure rise by a feed pump, enters a double-section bed hydrogenation reactor through a raw material dearsenizer, is mixed with hydrogen with a certain acetylene ratio in a pipeline, and enters a catalytic bed layer of each section of reactor to perform selective hydrogenation reaction, and the carbon-three hydrogenation process of the double-section bed reactor of the plant is a liquid phase hydrogenation process.

When the carbon three reactor of the plant operates, the cold and hot material flow in front of each section of the carbon three reactor is manually controlled by a DCS to adjust the material temperature at the inlet; controlling the flow of the prepared hydrogen and adjusting the concentration of the inlet hydrogen. The alkyne concentration in the material flow is measured by the on-line chromatogram of the outlet of each carbon three hydrogenation reactor, the MAPD concentration at the outlet of the carbon three hydrogenation reactor is ensured to be qualified (below 200 ppm), and the selectivity of the catalyst of the carbon three hydrogenation reactor is maintained to be about 20 percent at the moment.

The comparison results show that: compared with the manual control of the original factory, the method and the system can obviously improve the propylene selectivity of the carbon three liquid phase hydrogenation catalyst.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.