CN-121999891-A - Olefin conversion operation condition optimization method based on OCU device mechanism model

Abstract

The invention discloses an olefin conversion operation condition optimization method based on an OCU device mechanism model, and relates to the field of chemical industry and industrial informatization. The method decomposes the whole OCU device into a plurality of sub-process models, and builds a full-process model by using process simulation software. The model is calculated by adopting a simultaneous equation method, and a physical property database based on an SRK state equation is integrated. And calibrating model parameters through real-time operation data of the device, and adjusting convergence environment and model parameters according to heat and material balance to establish an accurate OCU device optimization model. The optimization platform is used for calculating by combining the optimization model, and providing an optimal operation setting reference for operators, so that the operation performance of the device is improved.

Inventors

• HUANG WEI
• PENG WEIFENG
• CAO JING
• LI YUANHU
• SUN XIANGLONG
• FEI YANREN
• ZHANG QINGYAO
• ZHANG QI
• XIE LIULEI
• ZHANG HUAYUN

Assignees

• 中控技术股份有限公司

Dates

Publication Date

20260508

Application Date

20251229

Claims (10)

1. 1. An olefin conversion operating condition optimization method based on an OCU device mechanism model is characterized by comprising the following steps: S1, dividing the whole olefin conversion device into a plurality of sub-process models, and building the sub-process models into an OCU device whole-process model by adopting process simulation software; s2, an OCU device full-flow model provides a data interface and a convergence environment for a reaction module; s3, establishing a parameter calibration model, and establishing an OCU device online optimization model based on the parameter calibration model; s4, respectively changing a convergence environment and calibration parameters according to the calculation content by using the OCU device full-flow model and the calibration model; And S5, the optimizing platform provides olefin conversion condition optimizing operation based on the established online optimizing model and the OCU device full-flow model.
2. 2. The method for optimizing olefin conversion operating conditions based on an OCU plant mechanism model as recited in claim 1, wherein a model hierarchy is determined, and the entire olefin conversion plant is divided into a plurality of sub-flow models including a reactor, a reactive rectifying column model and other sub-flow models.
3. 3. The method for optimizing olefin conversion operating conditions based on an OCU plant mechanism model as set forth in claim 1, wherein the overall process modeling is performed using process modeling software, and each device in each hierarchy is modeled using a standard generic or custom model, and sub-models in each hierarchy can be individually converged and run.
4. 4. The olefin conversion operation condition optimization method based on the OCU device mechanism model of claim 1 is characterized in that the whole-flow model is calculated by adopting a simultaneous equation method, the calculation content comprises all heat and material balance, a flow and temperature meter is provided with a module capable of reading DCS display data, the actual numerical value of the meter is recorded, and convergence environment, calibration parameters and variables are changed according to whether all calculated heat and material balance is achieved.
5. 5. The method for optimizing olefin conversion operation conditions based on an OCU device mechanism model of claim 1, wherein the reaction module comprises various reactors and a reactive distillation column model, the reactor model adopts a standard plug flow reactor model with flow simulation software, the reactive distillation column model adopts a strict distillation column model, and reaction dynamics are added on corresponding tower plates according to actual catalyst filling conditions of the reactive distillation column, so that the reactive distillation column is simulated.
6. 6. The method for optimizing olefin conversion operation conditions based on the mechanism model of the OCU device according to claims 1-4, wherein pure components and mixed physical properties in a calculation model are simulated by adopting an SRK state equation, a set-up diversity of the olefin conversion device is constructed, a physical property database in flow simulation software is called, and physical property data of an olefin conversion process is provided for the whole flow model of the OCU device.
7. 7. The method for optimizing olefin conversion operation conditions based on the OCU device mechanism model of claim 1, wherein the method is characterized by obtaining device working condition operation data and raw material product analysis data, preprocessing the data, and selecting proper calibration parameters and calibration variables according to process characteristics.
8. 8. The olefin conversion operation condition optimization method based on the OCU device mechanism model according to claim 1 or 7 is characterized in that on the basis of parameter calibration, optimization variables, constraint conditions and optimization objective functions are added, an optimization algorithm is selected, and an online optimization model is established.
9. 9. The method for optimizing olefin conversion operation conditions based on the OCU device mechanism model of claim 1, wherein the optimizing platform collects real-time process data of a DCS control system through an OPC Server and manually inputs raw material and product test data of a DCS operation interface into a real-time database.
10. 10. The olefin conversion operation condition optimizing method based on the OCU device mechanism model of claim 1 or 9, wherein the optimizing platform transmits the optimized operation parameters to a DCS operation interface through a real-time database, and an operator optimizes the reaction conditions and the rectification operation conditions.

Description

Olefin conversion operation condition optimization method based on OCU device mechanism model Technical Field The invention relates to the field of chemical industry and industrial informatization, in particular to an olefin conversion device operation condition optimization method based on an OCU device mechanism model. Background OCU: olefin conversion unit (Olefin Conversion Unit). The olefin conversion device is positioned at the downstream of the ethylene unit process, the raw materials are hydrogen from the ethylene unit, ethylene, unhydrogenated C5 and raffinate C4 of the butadiene extraction unit, diene in the C4 and C5 feed is hydrogenated into mono-olefin through C4 and C5 selective hydrogenation reaction, the C4 and C5 mono-olefin is reacted with the ethylene to generate propylene through olefin conversion reaction, and polymerization grade propylene is obtained through rectification. Meanwhile, butene isomerization and fractionation systems thereof produce polymeric-grade butene-1 as a polyethylene comonomer. With the development of ethylene devices in oil refining and coal chemical industry, the yields of high-value-added products such as ethylene and propylene are continuously improved, and a large amount of low-value-added C4 and C5 olefins are produced. The function of the OCU unit is to convert the low value added product produced by the ethylene unit into the value added olefin. The feed to the OCU unit is hydrogen from the ethylene unit, ethylene, unhydrogenated C5, and raffinate C4 from the butadiene extraction unit. The technical principle of the olefin conversion process is briefly described as follows, a C4 selective hydrogenation system is used for hydrogenating vinyl acetylene and 1, 3-butadiene in the raffinate C four to normal butene, a C5 selective hydrogenation system is used for hydrogenating normal/isoprene in crude C five to normal/isoamylene, separating normal/isoamylene in the crude C5 selective hydrogenation system through a depentene tower, a deisobutene system is used for isomerizing 1-butene to 2-butene and simultaneously separating 2-butene, isobutene and isobutane, an isobutene isomerization system is used for converting isobutene to normal butene, an olefin conversion system is used for reacting 2-butene, 2-pentene and isopentene with ethylene to generate propylene, polymerization grade propylene is obtained through a deithylene tower and a deipene tower, and polymerization grade 1-butene product is obtained through butene-1 fractionation tower rectification by a butene isomerization system. The OCU device has complex flow, is used as a core device for whole-plant propylene production, is also a key device for C4C5 resource utilization, has relatively stable operation process, and has great lifting potential. The OCU unit feedstock properties are affected by the upstream ethylene unit feedstock products, resulting in variable unit feedstock composition, frequent production scheme adjustments, and higher unit energy consumption. The energy saving and consumption reduction aims are realized by optimizing the reaction conditions, the rectification operation conditions and the like. The optimization of the OCU device is mainly focused on optimizing and reforming a flow process at present, for example, patent CN110078581a describes that the purpose of protecting an olefin conversion reaction catalyst is achieved by hydrogenating a raw material to remove the diene content in the raw material through the optimizing process, so that the benefit of the device is improved, but no scheme for simulating the process to realize the optimizing operation is provided. Disclosure of Invention The invention aims to provide an olefin conversion operation condition optimization method based on an OCU device mechanism model to solve the problems that the operation optimization of the conventional OCU (olefin conversion) device depends on manual experience and lacks a systematic optimization method, and the prior art focuses on process transformation rather than operation optimization, and further aims to solve the problem that the optimal operation parameters for maximizing the economic benefit of the device are difficult to calculate by establishing an accurate full-flow mechanism model, and further aims to solve the problems that the manual adjustment is not timely and accurate until the device is not continuously operated in an optimal state by optimizing a platform and the full-flow mechanism model. To achieve the above object, the present invention provides a method for optimizing olefin conversion operating conditions based on an OCU device mechanism model, comprising: S1, dividing the whole olefin conversion device into a plurality of sub-process models, and building the sub-process models into an OCU device whole-process model by adopting process simulation software; s2, an OCU device full-flow model provides a data interface and a convergence environment for a reaction module; S3