TW386041B - Method for controlling with precision a process for separating constituents of a mixture, in a simulated moving bed separation system - Google Patents

Description

Revised page of Chinese Specification for Patent Application No. 87106265 (November 88, V. Description of Invention (13) The calculation algorithm includes a non-linear physical model of a real moving bed unit, which can calculate the ratio (as defined in paragraph II) Therefore, the controlled variable can get a fixed value in advance. The calculation method is laborious, not fast and implies that sufficient measurements are available online. A) The principle of ratio calculation; it will be appropriately selected by those skilled in the art The number of equations in the form of m (0 is limited to the controlled variables in the form of m, where m is less than or equal to η ', that is, a group of adjacent stages including one or more regions, where η is a partial ratio. By defining an algebraic expression of the statistical model and the available measurement of the concentration in the liquid phase at the endpoints of the segment, these m controlled variables can calculate m ratios or m of these ratios containing (nm) parameters Merging 〇b) The purity of the 4-zone unit is calculated. For example, the purity ξρ can only be determined from the knowledge of the composition of the extract (Xert): gp = F (Xert) Select a part that contains region 1 and The segment portion of domain 2 (FIG. 3), wherein the two ratios thus fix. The ratio r1. The knowledge of the concentration Xe and Xs of all components in the liquid phase at the endpoints and the knowledge of the setpoints (controlled variables) of purity can be used to calculate the ratio R2. In fact, from equation (7) and for component i (the index m represents the true measured value), we can find out:-at stage e + 1:

Ri (xmi, e-Xi, e + i) + (yi, e + ryi, e + i) + K (Xi, e + 2-Xi, e + 1) = 0 -16- This paper size applies to China Standard (CNS) A4 specification (210X297 mm) First, please read the note on the back to fill in the original text], ίτ Printed by the Central Consumers Bureau of the Ministry of Economic Affairs, printed Α7 Β7 Printed by the Consumer Cooperatives of the Central Bureau of Standards, Ministry of Economic Affairs 2. Description of the invention (彳) Field of the invention The present invention relates to a method for accurately controlling a process for separating components of a mixture in a simulated moving bed separation system from discrete concentration and flow measurement. This method is especially used for aromatics. Separation of hydrocarbons. BACKGROUND OF THE INVENTION ** In the industry, there are many continuous separation methods based on the selective adsorption of at least one of the components of a fluid mixture, especially those known as simulated pseudochromatographic analysis methods. Below a liquid, gas, or supercritical mixture, certain porous solids significantly retain the properties of the individual components of the mixture with more or less. ^ Separation or fractionation methods based on chromatographic analysis are most commonly performed in equipment that contains a set of columns or column sections connected in series to form a loop. The injection points for the mixture to be separated and the solvent or de-gelling agent, and the fluid extraction points for the extract and the raffinate will be defined in different areas and distributed along this circuit. The same liquid flow passes through all towers or tower divisions in the same area. This setup is most often composed of four main areas. However, some have only two regions (in this example, the region contained between the raffinate extraction point and the solvent injection point is omitted). There is also a device which has five areas where the portion of the extract separated from the solvent is re-injected between the extract extraction point and the feed injection point. Others may include five to seven zones, in which a second fluid is allowed to flush the pipelines that transport several fluids to prevent contamination. The stationary phase is formed from a porous solid whose particle size has been determined. __________ * 4-This paper size applies to Chinese national standards (CNS> M specifications (2) 〇χ Ｍ? 公 Only> (Please read the precautions on the back before filling out this page) A7 __ 一 _ B7_____ printed by the staff of the Bureau of Standards and Consumers V. Description of the invention (2) The mixture is fed into the tower and then replaced by a carrier fluid or desorbent, and each component is based on whether it is Retained by the stationary phase more or less significantly to flow out one after another. In the solid reverse flow process (Figure 1), the concentration and stability of the stationary and fixed phases are developed in the separation column 1 The positions of the feed point "A + B, the injection point of the eluate s, and the extraction point of the extract EA and the raffinate RB remain fixed. The adsorbed solid 3 and liquid 2 are circulated in a reverse flow. At the same time Placed on one of the towers (at the junction of Zone I and Zone IV), the mast transport system and the circulation pump P respectively allow solids to be sent from the bottom to the top and, conversely, liquids from the top to the bottom. The only component in liquids and solids is the eluent carrier fluid. The process of the moving bed method may allow to avoid the main difficulties inherent in the solid moving bed method, which include recycling the solid phase positively without abrasion and not significantly increasing the porosity of the bed associated with the fixed bed. In order to simulate its substitution effect, the solid is placed in a fixed bed of a certain number η arranged in series (usually 4 sng 24), and the concentration distribution is destroyed in the entire closed loop at a substantially uniform rate. In practice, the continuous conversion between the injection point and the withdrawal point is performed by means of a rotary valve or more simply by a set of appropriately controlled on-off valves. Each entry-exit flow cycles in a given direction in each stage The transformation is equivalent to simulating the replacement of the solid adsorbent in the reverse direction. The reverse or co-current simulated moving bed chromatography analysis system is described in, for example, US Patent No. 2,985,589 or US Patent No. 4,402,832. One is used to feed with at least two components in at least one eluent_ -5- This paper size applies Chinese National Standard (CNS) A4 specifications (2〗 0X297i5 ^ ---— 1 ^^ 1 » -·-1 ·---111-.--II I: 1 11 II----I —— ------ 'I fr.: ¾,-' 口-., (谙 Please read the precautions on the back before (Fill in this page), A7 A7 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. The invention description (, the system is separated into at least two remaining systems, which usually contains: 4S "24) serial installation _ Road color layer analysis The column or column area communicates with the liquid, supercritical or gas mixture which is circulated and milled. The loop has at least one feed injection stream, at least one special agent injection stream, 'at least: = extraction extraction stream, and at least- A raffinate & extraction stream, the component mainly: better in the extract or in the raffinate. The main inlet flows are feed flow and eluent flow, and outlet flow / extract flow. The raffinate is taken out under the control of pressure, and the raffinate: I is equal to the sum of the inlet flow minus the extract flow. In addition to these controls: "In addition to flow," it also has a controlled circulating flow, which is related to the position of the lower pump at a given interval. According to the type of separation to be performed, calculate the relative position of each of the four circles of flow around the bed to obtain the behavior of one and thus determine four different regions in the method G shown in Figure i. US patent number? d57: 260 millet and 11 ^ 4 stickers. No. describes a control method of a simulated moving bed system for separating a mixture of components, which contains two multi-tower bed columns connected to each other #, and at least one of its features is Control the purity of a component or its yield or a combination of both. This method involves measuring the concentration of the components of each mixture circulating in the pipelines connected to each other, especially by near-infrared spectroscopy, and using a multivariable regression or god = network type. Iterative adjustment algorithm Method, which tends to reduce the difference between the actual value and the setting value of characteristics. The algorithm used here is the "black box" formula, which has the disadvantages of this method: considerable implementation time, because the result is only obtained after a number of tests, which can only be tested. It is used in the field and its 6 paper sizes are applicable to China National Standard (CNS) A4 specification (210X297 mm) f. Read the notes on the back before filling in this page. Policy,-* A7 B7 Central Bureau of Standards, Ministry of Economic Affairs Printed by the Consumer Cooperative Cooperative 5. Description of the invention (4 can only get very poor accuracy. In the following, the following words are marked:-bamboo shoot control variable: must be Ning from 4.zl 1 '"V fixed close to the pre Decide the set value of the set value, and it will display the process to the winter sigh, change the purity, separate the rare element pair-the rate of the given component, etc .; The operator changes the soil traverse, u ι number, such as flow • volume or allow to simulate the bed < replacement valve replacement period, etc.-access to j 彳 variables · Mainly acting on the area > Ran & '. ~: The 5 meaning variables in soap, such as acting on the part of the Buddha that is contained in β. + This is determined and transmitted to the operating variable. ^^ The number is the ¥ system algorithm. It needs to be reminded that the purpose of high-level private control intended to be used to separate the operation of the loop is to calculate a control law β benefit; then (all of the operating variables during the time ^ process), in order to: < *% J1: star 'ii g to calculate 4-able to produce Zhu _ or a number of control variables that have been selected in advance Two different control rules for the transfer of control, and adjustment operations, that is, to calculate-can _ all external control of the process disturbances as much as possible (or at least asymptotic) compensation, so that the previously selected control variables remain In the example of a simulated moving bed system, the disturbance caused by the thermodynamic and geometric parameters of the adsorbent (of course, the limited decline of the properties of the adsorbent) over time can also be compensated by adjustment. Some goals are achieved by an automatic control method intended to be used in the process of separating the components of the circulating fluid mixture according to the present invention, which can overcome the aforementioned disadvantages. It is not based on the " black box It is based on the more controlled paper size and applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm) Ί.Γ -------- J 衣 -----— Order (谙 Please read the notes on the back before filling this page.) A7 __B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the Invention (5)-The method of production is allowed by the non-linear mode of the separation method. Summary of Invention The method according to the present invention is applied to a simulated moving bed system (or unit) for separating components, which includes a closed loop consisting of tower beds connected in series with each other and containing adsorbent material. The fluid injection and extraction points are divided into several areas, the device for injecting fluid into the circuit, the device for taking fluid out of the circuit, the injection point and extraction point conversion device capable of reversely replacing the beam tower, and Device for measuring each variable (such as concentration, flow rate, valve switching period, etc.). It contains: ~-Measurement operation variables and the concentration of certain components, which are required to calculate the control variables at many points on a separation circuit at least equal to 2;-The measurement variables are lacking, and a separation is used The system (can be a non-linear mode, or a linear approach to a given operating point; ^) has determined the mode of operation to determine the respective labeled ratio 値 (Rk), which is in each different area, intermediary Between the fluid flow rate (QK) and the simulated adsorbent material flow rate, to bring the control variable to or back to the determined setting, and • From this ratio (Rk), determine the value of the desired operation variable. On a separation loop region containing an array of adjacent stages including the η region, η ratios 値 (Rk) are defined. This method usually includes the root flow rate (D) and the concentration 値 (X) to define the m-phase controlled variable (Ξ), where m 値 is less than or equal to η 値, measure (to the example of the non-linear control mode) the concentration (X) of the ~ end point in the liquid phase and determine m this ratio 値 (Rk ) Or the ratio of m to m, which contains (nm) parameters. A specific example of a separation circuit with four main areas, Example-8-1 Paper size ^ Use Chinese National Standard (CNS) A4 size (2ΐ〇χ29 · 7mm) '(Please read the precautions on the back before (Fill in this page) Λ 衣 · 、-° A7

Printed by the Consumers' Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs. For example, the control variable (ξ) of the loop efficiency and the purity of at least one component of the mixture is measured at the same time from different concentration lines for control. For example, Raman-type on-line analysis, color layer analysis, or near-infrared (NIR) analysis is used for concentration measurement. According to a specific example, in an example of a separation unit or system with four g domains, at least one of the following four quantities is selected as the controlled variable: the first group of fluids taken from the circuit The purity of the components, the yield of the separation system for one component (same as the first component or the others), the first component in the first four of the four areas related to the circulation direction of the flow. The tail amount, and / or the tail amount of all components except the first component, is in front of the last of the four zones related to the direction of the fluid. Under a known ratio (Rk) in a separation system containing a specific number of p's, this method allows the decision to feed from at least one additional injection point and / or at least one extraction point to the separation circuit. The corresponding 値 of the additional ratio 値 is based on the known 値 of the ratio 邻近 of the adjacent area and according to the injection and / or withdrawal flow considered. The ratio between the component concentrations in the removed fluid can be selected as the controlled variable. An optimization algorithm can be used to advantage. The method used can be easily used to control many controlled variables (ξ) * as long as it is the ratio (Rk). These controlled variables can be, for example, production · volume, solvent ratio, tail measurement, etc. The method according to the present invention can maintain stable operation of the separation unit, even in the presence of changes in flow rate or feed quality. -9- ^ Paper size applies Chinese National Standard (CNS) A4 specification (210 > < 297mm> ~~:-(锖 Please read the weeping matter of back teeth first and fill in this purchase) Pack. A7 B7 Central Ministry of Economic Affairs Printed by the Consumer Bureau of the Standards Bureau. 5. Description of the invention (7) A brief description of the diagram. From the "Read the following description of the non-limiting specific implementation examples, and with reference to the drawings" according to other features of the present invention and The advantages can be made clearer:-Figure 1 is the flow of the solid moving bed separation circuit,-Figure 2 is the principle of discontinuity used by Huiming for the material balance equation,-Figure 3 is the two areas illustrating the calculation of the ratio calculation The flow of the interval '-Figure 4 shows the flow chart of the phases of the loop control method,-Figure 5 is the flow chart of the separation circuit with four areas, four injection or extraction points, and eight measurement points, -7F in Fig. 6 is the time record of the feed composition change, which is used to illustrate the adjustment example in the following simulation. Figure 4 shows the time when the two controlled variables progress due to the result of changing the feeding. Record, purity of the extract Unit yield,-Fig. 8 shows the control efficiency provided under the same conditions by applying the method according to the present invention, and-Figs. 9 to 2 show that it is related to four operating variables when the process is stable The progress time records are respectively the circulation flow rate (Figure 9), extract flow rate (Figure 丨 0), conversion period (Figure 11), and raffinate and material flow rates (Figure 12). The invention details a closed separation circuit and The separation unit of the simulated moving bed, which is divided into at least four zones, and each zone is separated from the neighbor by injecting or extracting the stream. The injection and the extracting stream are essentially replaced at a fixed time interval. The The circuit has—the pump used to circulate the mixture, and its output is controlled-10- This paper size is Ningguo National Standard (CNS) A4 »(210X297 mm) (Please read the precautions on the back before filling this page ) -----, Dad ------ Order A? B7 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs. 5. Description of Invention (The scholarship is placed in two consecutive towers or tower sections, and may be at least A tower section .. and i device, which also attacked A continuous tower or a Raman-type measuring device can be advantageously used, which is, for example, applied by the applicant for two French patents No. 2,699,917 (country A patent No. 5,569, outline No. J). It can be used in a large number of The instant concentration and volume can be distributed at different points in the circuit of the user. Randomly select n bright g also be clothed in different zones (for a separation system with four zones, the usual range is 2 ”8 winter Jane) The measurement system can fully ensure the smooth operation of the calculation control method. 'I) Selection of variables a) Controlled and controlled variables are defined as one of several variables: (1) $ = F (D, X), Where -X # — vector, represents the concentration of each component of the liquid phase at different points (this can be. Table shows the average of the instantaneous or taken during the transformation period). -D is a vector 'where each element is the internal injection or extraction flow. • I _ The purity of the components in the liquid phase at any point in the early yuan (for example, outflow) can be used as an example of the controlled variable: ξ = χί / (χί + ^ ρ〇, Λ- t, -Xi is Concentration of component i at a given point. -Impi is the concentration of other components that are considered as impurities at this point (which can exclude certain components such as eluents). -11-This paper scale applies to China National Standard (CMS) A4 specification (210X297 mm) (Read the precautions on the back before filling this page) ^ — «^ 1 TJ m nn ^^^^ 1 · • va. A7 B7 V. Description of the invention ( The calculation of this controlled variable at a given time, and therefore includes measurements of the liquid phase t at the point or points of the circuit, all concentrations present. These measurements can be made, for example, by Raman-type analysis mentioned above or by any Others can be controlled. The controlled variable can be freely selected in advance. In the example of the friend four-zone unit, the operator * often uses the desired amount. For example, it can be selected as the controlled variable: 1) Among the extracts The purity of one component, 2) the yield of the component to this component-3) points 0 and 2) the end of the component under consideration After the zone i ^ (related to the circulation direction of the fluid), 4) Except for the components considered at points 1), 2 > or 3), the tails of all components are before the zone 4 (and Fluid circulation). b) Control variable: The method according to the present invention includes selecting a control variable by giving an operation variable, which is so that the control of the progress of the controlled variable can be directly determined. .........--11 '-. 1-. 1--. I (I read the precautions on the back and then fill out this page) These control variables are transformed into " traditional " operations Variables are always beyond the limits of solid physical applications related to the process and the size of the equipment. They also have a one-to-one relationship between them, which is a necessary condition for the separation system to be well controlled. _ In the example where all operating variables are free (that is, these 値 can be fixed freely without having to consider physical constraints), the necessary number of independent control variables' is equal to the number of regions forming the separation unit. 12- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (2 丨 〇 < 297 mm) A7 B7 Printed by the Staff Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (10 Simulated moving bed separation system The operation system is almost the same as that of the solid moving bed system, which is well-known. When the latter is opposite to the main liquid flow, the circulating flow is = J. The following is the given timing ... a

(2) Q s = (% V micro * Vcolumn) / T

Qs is " solid flow ... (corresponding to the effective capacity), which is equal to the valve changer generated in the simulated moving bed unit.

(3) q e = (% V macro +% V meso +% V vi) * V column) / T qe is the "reverse flow of liquid", which is equal to the one generated by the valve transformation. It corresponds to the amount of liquid contained in the meso- and macropores as well as in the external holes or added to the bed holes ^ particle holes. It is usually regarded as " blocking current " or current carrying. It should be the stagnation of the liquid adsorbed by the micropores of the non-sock adsorbent., '' In the relationship between (2) and (3) i 11- T is the transition period of the valve of the simulated moving bed unit, -Vcolumn is the basic volume of the unit area (contained between two consecutive injection and extraction points, and the volume is 'activated or not'),-% VmiaO,% Vmeso ,% Vmacr0,% Vv 丨 are the micropores (effective volume, mesopores, megapore body wheels and the percentage of external holes in the tower bed.) The static volume that does not appear in formula (3) and corresponds to the continuous sieve bed The static volume is based on the overall increase of each percentage of formula (3). For these two unit forms, the external liquid flow is the same. In the other aspect, the simulated moving bed and the solid movement The internal flows between the beds are not the same. These flows are related by:

Qfc = Fk + qe -13 This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 cm) .. —j_-.. I Binding (Please read the notes on the back before filling this page} A7 B7 V. Description of the invention (H). Where Qk is the liquid flow through the region ^ of the simulated moving bed unit,

Fk is the liquid flow through area k of the solid moving bed unit. If we use the example of a non-adsorbed tracker that remains stationary, it must flow to zero for a real moving bed unit, but it is equal to the flow restriction qe for an simulated moving bed unit. ~, From these definitions, the selected independent control variable is 4 dimensionless ratio 値 or ratio 値 Rk (k =〗, 2, 3 or 4), which is the main liquid flow in each zone and In the whole unit, the fixed solid flow is: (4) Rk = Qk / Qs 4 ratio for control. The selection of Rk is the material balance equation of the model of the solid moving bed unit, which is under steady state at Discontinued Tower Column Division. Considering the reverse fluid flow, the discontinuity performed with three points j, j + Ι). The property is represented by · by the following example. By specifying that the concentration of component i in the liquid phase at point j is Xij and the equilibrium degree of this component in the solid phase at point j is yu '(圏 2) The material balance for this component is as shown in the table. Bottom: Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs— ^ n 4VH t ^ i ^ l ml m ^ lmnmn ^ i tf fm i.,-S., Va (Please read the precautions on the back before filling this page )

Qk (Xiij.rXij) + Qs (yij + i-yij) + tle (xy + rxi1i) =: 〇 That is, divide by Qs: (5) (Qfc / Qs) (Xij-i-xy) + (yiJ + i-yij) + (qe / Qs) (Xij + rXij) = 0 According to the individual definitions of Qs and qe, expressed by the relationship (1), (2): _% Vmes〇 ++ κ = Determine Qs% Vmicro and Formula (5) is expressed as follows: -14- This paper size is applicable to Chinese National Standard (CNS) A4 (2 丨 mm) A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (12 ) (7) Rk (xij.rxu) + (yy + 1-yij) + K〇 (xu + rxij) = 0 The only control variable (the freely modifiable parameter of the above equation) is the ratio 値 Rk, consider it Definitions, which are known in each zone forming a car element. The number of ratios is the same as the number of zones. According to the user or operator's preference, these ratios can be transformed into ordinary operational variables, which have a non-singular algebraic relationship with Qki 値. In a 4-zone unit, there is a one-to-one relationship between the 4 ratios and 4 of the following 5 operating variables: T, Ql, Qsolvent, Qextract, Qfeedstock. The fifth variable is required. Decided to set the parameters (pamm). It is most often the feed flow Qfeedstock. As a result, the relationship between the following ratio 値 and the operating variable is obtained: t

• a ».. A if param = Qfeedstock T =% V micro * V column * (R3-R2) / param

Ql = param * Rl / (R3-R2) 'Qsolvent = param * (Rl-R4) / (R3-R2)

Qextract = param * (Rl -R2) / (R3-R2) This system is defined if param < > 0 (which is also equal to R3 < R2). Select 4 variables out of 5 to allow the example to work:

I '-with a fixed or variable feed, but it is applied by a process,-or with a fixed solvent flow,-with a fixed valve change period, and so on. II) Ratio calculation algorithm 1) Non-linear mode -15- This paper size is applicable to China National Standard (CNS) A4 specification (2 丨 0X297 mm) 11-· _-------it ^ i — — ^ M __ _ y,. · Wear. (Please read the precautions on the back before filling this page)

Revised page of Chinese Specification for Patent Application No. 87106265 (November 88, V. Description of Invention (13) The calculation algorithm includes a non-linear physical model of a real moving bed unit, which can calculate the ratio (as defined in paragraph II) Therefore, the controlled variable can get a fixed value in advance. The calculation method is laborious, not fast and implies that sufficient measurements are available online. A) The principle of ratio calculation; it will be appropriately selected by those skilled in the art The number of equations in the form of m (0 is limited to the controlled variables in the form of m, where m is less than or equal to η ′, that is, a group of adjacent stages including one or more regions, where η partial ratio is defined. By defining an algebraic expression of the statistical model and the available measurement of the concentration in the liquid phase at the endpoints of the segment, these m controlled variables can calculate m ratios or m of these ratios containing (nm) parameters Merging 〇b) The purity of the 4-zone unit is calculated. For example, the purity ξρ can only be determined from the knowledge of the composition of the extract (Xert): gp = F (Xert) Select a part that contains region 1 and The segment portion of domain 2 (FIG. 3), wherein the two ratios thus fix. The ratio r1. The knowledge of the concentration Xe and Xs of all components in the liquid phase at the endpoints and the knowledge of the setpoints (controlled variables) of purity can be used to calculate the ratio R2. In fact, from equation (7) and for component i (the index m represents the true measured value), we can find out:-at stage e + 1:

Ri (xmi, e-Xi, e + i) + (yi, e + ryi, e + i) + K (Xi, e + 2-Xi, e + 1) = 0 -16- This paper size applies to China Standard (CNS) A4 specification (210X297 mm) First, please read the note on the back to fill in the original text], ίτ The consumer cooperation of the Central Standards Bureau of the Ministry of Economic Affairs Du printed A7 A7 Printed by the Consumers Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs V. Description of the invention (14)-The stage j included between stage e and extract extraction stage ext: R1 (X i jr xij) + (yi j + ry ij) + K (X i j + 1- X ij ) = 0-Corresponds to the stage of extracting ext: R 1 (X i, ext-l_ X (yi, ext + l_ yi, ext) + K (X i, bxt +) · X i, ext) = 〇- In the phase k included between the extract extraction phase ext and the phase sl: R 2 (X i, kr X i, k) + (yi, k + ryi, k) + K (xi, k + ix i, k) = 〇- In phase 卩 -1: R 2 (χ i, s-2- xi; si) + (ymi) S- yi, si) + κ (xm ijS- Xi.s.0 = 〇 ^ c) solution Considering the form of the aforementioned equation, if the number of equations is equal to the number of unknowns, there will be a single solution. The unknown is the concentration of the components present in the liquid phase at one stage of M plus the ratio in region 2 (i.e., + 1 ') where nc represents the number of components. The number of, = formulas is equal to the number of stages contained between ... and 乘 times the component 2 (two I? —. 1). A supplementary equation is controlled by the desired. Counting to produce, that is, P_F (xert) = 0. The nonlinear algebraic equation of the size of this system: Cnc (s ~ e + l) + l] * [nc (s-e + l) + i] is solved by Newton's approach. The other round-out functions can be determined similarly. ^ Yield, tail Some others are obviously related to Liu Zhangyu. For example, the yield of component i of the separation unit can be: added to the unit—-17- applicable to the TiS standard (;) A4 size (210x297 ^ ~-^----------. '^ 衣--- n II (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Description (15) Yield = 10 0-(Q raP XM) / ( Q feedstock * X 1 / eedstock). This equation can be simply expressed as a function of ratio 値: d) Example-The simulation presented below is for a Benzene separation unit with a simulated moving bed and 4 zones' (In terms of any payment, it does not limit the scope of application of the present invention). I tried to purify the para-xylene obtained from the extract. The feed contains 5 components: para-xylene, _-xylene, o-xylene, ethylbenzene and raffinate. The two main controlled variables are the paraxylene 1 degree and the paraxylene yield of the separation unit. The magnitude of the controlled variable is related to the position of the separation unit in the aromatic processing circuit. The analytical equipment must be suitable for the output function to be measured in accuracy and response time. e) Selection of controlled variables: 1) The purity of para-xylene in the extract can be determined by the following relationship: 41 = P.5Ce / (PXe + IMPe), where -PXe is at the extraction point of the extract The average p-xylene concentration in the liquid phase, -IMPe is the sum of the concentrations of other components in the liquid phase present at the level of the extraction point of the extract that is far from the solvent (and possibly the raffinate). The 値 of ξ 1 is mainly related to IMPe 値, because PXe is essentially fixed. IMPe is mainly related to the ratio 値 (R2) in region 2. 2) The p-xylene yield of the unit is determined by the following relationship: -18-This paper size applies to China National Standard (CNS) A4 specification (210X297 mm) ^-Packing. Please pay attention to this page before filling in this page) 5. Description of the invention Among them, PXc, PXs and PXr are the concentrations of para-xylene in the liquid phase of the feed, solvent and raffinate respectively. Q extract, Q feedstock, Q solvent and Q faffinate are stroke extract, feed, drop The flow rate of the agent and the raffinate and the material. _ The 値 of ξ2 is mainly related to the 値 of PXr, so it is related to the ratio * of the zone 3 (R3). It is also related to the flow of the feed, the solvent and the raffinate, and the feed and The paraxylene composition in the solvent is related. Considering the previous explanation of the available control variables for units containing four zones, two additional controlled variables must be selected. 3) Behind zone 1 (about the circulation of fluids) The tail amount of para-xylene in the liquid phase at the ring direction) can be determined by the following relationship: ξ3 = Ρχ4 The selected measurement point is located at 3/4 of the length of zone 4. The 値 of ξ3 is mainly related to the ratio 値 (R1) of zone 1. 4) The tails of all components except para-xylene at the front of area 4 (about the circulation direction of the carcass) can be determined by the following relationship sheet: 'ξ4 = ΙΜΡΙ where ΙΡΙ is except para-xylene Concentrations of all components present in the liquid phase with the solvent (and possibly the raffinate). 19- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210 × 297 mm) (Please read the precautions on the back before filling out this page) -Ai,-° Printed by the Consumer Cooperative of the Central Bureau of Standards, Ministry of Economic Affairs Α7 Β7 5. Description of the invention (17) The selected measurement point is located at 1/4 of the length of zone 1. The 値 of ξ4 is mainly related to the ratio 値 (R4) of zone 4. f) Implementation of control algorithms: control variables or ratios | This control principle includes the use of model equations on unit sections. In the selected example, the following three ^ segments are used:-The first segment T1 is included between the middle of the region 4 and the middle of the region 1. It can calculate the ratio 値 in zone 4 (R4) and zone i (R1) simultaneously. This system is possible because the controlled variables ξ3 and ξ4 are determined in this section. -The second section is contained between the middle of zone 1 and the middle of zone 2. With this segment known, the ratio 値 R2 can be calculated. The variable is located in the _center of this section. -The third section T3 is included between the middle of zone 3 and the middle of zone 4. This segment can calculate the ratio 値 r3 with R4 known. ^ · Number, 3 is located in the middle of this section. From a practical point of view, the operating variables that can be obtained in the selection unit are wise in the future. The following variables are selected: extraction stream, circulating stream, detergent stream and valve change period (so the feed stream is selected by the operator and the residual stream can be deduced by mass balance at all times). The circuit of the algorithm considered for this example 'is shown in Figure 4. g) Simulation Perform a simulation from the knowledge model of the separation unit. This mode includes the knowledge of heat, learning, and dynamics. The thermodynamics of this system is represented by adsorption isotherms. In the example examined here, these isotherms are nonlinearly coupled. It can be η-component generalized blue moor _ -20- this, .. the wave ruler anti-common Chinese national sample (CNS > Α4 specifications (2 丨 0'〆29 "? mm (谙Read the notes on the back before filling out this page}

V. Description of the invention (18 A7 B7 printed by the Central Standards Bureau of the Ministry of Economic Affairs, Printed by the Shellfish Consumer Cooperative, Ϊ = 1Γ), etc., fixed ... optional) or preferably non-fixed selective <isotherm, for example, connected by a slash The selectivity of the two extremes, or the blue isomerized by the general formula of η-component _ 富 _ 英 德利奇 aangmUir-Freund „ch) isotherm. The dynamics of this system is specified by the theoretical board or by η The fraction of each component of each component is represented by the dispersion coefficient. The number of measurement points used is 8, which is as shown in Figure 5. In this example, the knowledge model used in this example is Blue Moore_Fu Roying Derich isotherm with cascade of S theory board. The description of the measurement and its position are related to the selection of the section, which has been selected as described above; of course, 'this selection is here only for illustration and The present invention covers the merging of all sections compatible with the desired target. Oral presentation <Results-an example of control. This method is based on a fixed setting of purity ⑼ and yield (95%) '' The composition of Jinke has changed substantially. After a stable operation of 纟 + minutes (Figure 6), For the feed, the volume of a component is described as follows: 'Ding 〇1 = 0,022 Ρχ = 0.290 MxOx = 0.598 EB 0.102 Par = 0.032 A volume composition of a certain feed is as follows: T 〇1 = 0.024 PX = 0.290 first read the back of the matter and then 4 v) 5.

I 1 Ding-21 This paper size applies the Chinese National Standard (CMS) A4 specification (2 丨 〇297297 mm) 5. Description of the invention (19 ΜχΟχ ΕΒ Par a.512 0.190 0.032 ΑΊ Β7 Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs The disturbance described in Fig. 5 is shown in Fig. 7 due to the lack of control method. The effect of Ascendant is shown in Fig. 7. It is converted to a reduction in pure i of K2% and a yield of 40%. This process is therefore highly sensitive to disturbances in the quality of this feed. 'The same disturbance is applied to the process according to the invention (the stability of the figure is carried out for about 180 minutes, i.e. 3 hours. The difference in purity is the' largest yield difference ' It is less than 0.45%. It can be noticed that the two R's * are the four controls that are significantly deployed at the same time (Figures 9 to 12). In the presence of disturbance, it is difficult for the operation of the separation circuit to be borrowed by the operator. As mentioned above, it must operate four variables at the same time. Under this condition, 'for highly skilled operators', the fastest can still spend 24 hours, hours and several consecutive stable operations in order to stabilize the process. Deviating from the specifications necessary for stability The significant reduction in the production period, which is implemented in the industry according to the method of the present invention, is transformed into an increase in relative productivity. H) Deformation: In order to place all operational variables, the algorithm can also be used with The numerical simulation mode of this method is used in combination. The purpose here is in many examples: unit scale, unit start, to optimize the operation of the unit mode, so that the final optimization is close to one that is already correct. Pre-existing units, etc. of different separation problems. Of course, this use can only be considered as close to the physical solidity as mentioned in the previous section 8). The process is not significant_ M J --.--- ' J Pack-(谙 Read the precautions on the back before filling this page}, 1Τ

J -22- This paper size applies to the Chinese National Standard (CNS) (210X297 mm) A7. Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (20). In this example, of course, the adjustment 値 cannot just produce the expected performance ′ Depending on the accuracy of the simulation mode, it may be lower or higher than the desired one. The loop of the algorithm will then be able to accurately reach the specification from these close 22> linear mode. * According to the second implementation, the ratio of 眞 to 眞, which is the actual value of the measured variable, determines whether a single variable can be borrowed (output behavior The representation is related to the variation of rotation) or the multivariate (the representation of several output behaviors is related to several inputs) linear mode to perform. These "simple" mode decisions are made from a set of experimental tests that work in conjunction with a process that is operating in a stable state close to the expected one. These modes usually represent only stable operating points close to the system. It can be easily synthesized from these modes—the traditional linear control method (internal-mode control, predictive control, etc.). The simplicity of this square can easily calculate simple and laborious control laws to compensate for the inaccuracy of the chosen representation. In simulation, the performance test of the calculated control law corresponds to the result of the control law calculated by the non-linear physical mode of the process. III) f Shi Zhiji 1) Additional injection points As mentioned above, the use of non-linear and linear control in the 4-zone unit example can be absolutely applied to the borrowed or generated by multiple fluid injection points In a separate unit containing a larger number of regions. In this example, the calculations for 値 —Rl, R2, R3, and R4 remain the same, even if it takes into account that additional injection streams have been added by the operator (eg, directly or indirectly in the proportion of the feed or extract stream). The ratio of this ratio is from the known Zheng Jin ratio and the -23-jujube paper size applicable to the national standard (CNS> A4 specification (210X297 public shame) ^ nn ^^^^ 1 ^^ — ^ 1 I .....— HI— I ----1 · tm nn a _ i · 5 Γ 谙 Read the notes on the back before filling in this page)

* 1T Printed by the Central Consumer Bureau of the Ministry of Economic Affairs, Consumer Cooperatives A7 B7 V. Description of the Invention (21) The new injection simply generated by the law's inflow rate is related. 2) Additional extraction points, as described in extension 1), exist in the use of non-linear and linear control in the 4-zone unit example, which can be applied to a larger number of areas generated by adding one or more fluid extraction points The separation unit +. In this example, the ratio 値 R2 or R3 is calculated based on the additional ratio 产生 generated by the new injection point. Therefore, for each fluid withdrawn, the output function must be set to the desired number (such as purity or yield specifications). In this example, for each process, the added extraction flow rate becomes a new independent operating variable. If there is no required specification for the extra take-out, then the flow is borrowed by the operator to join and we are in the same situation as the extension 2). 3) Additional injection and extraction points, as mentioned above, exist in the 4-zone unit example f / 卩 linear and linear control, which can be applied by adding one or more fluid injection points and one or more fluid extraction Dots produced by the isolated monograms containing a larger number of regions. The claims described in the two previous paragraphs can be repeated and comprehensive. Today) Can be used as the controlled variable No matter the selected control mode is 4?丨 The controlled variable described above: the purity of the component, the yield of the component (same as purity or other), and the non-linearity or linearity of the tail volume 区 in zone 1 and zone 4, which can be replaced by a new controlled variable , Which is the ratio 取出 between the components of the fluid. For example, in the extract, one can choose to control the purity of para-xylene (mainly R2) and the variable determined by the ratio of the concentration of ethylbenzene and the concentration of m-toluene and o-xylene. The latter variables will be mainly affected by it. -24- This paper size applies to China National Standards (CNS) A4 (2 丨 οχ ”7mm) —_ h―,. I Binding ^ (Please read the precautions on the back before filling this page) A7 B7 V. Description of the invention (22) 5) Optimization of control mode The aforementioned nonlinear and linear control can be combined with the optimization algorithm, which can propose a series of settings for extending the controlled variable described in 5) 値Therefore, in reducing the function determined by the operation limit, the optimal operation can be ensured. _, Binding (Please read the precautions on the back before filling this page) Printed by the Central Consumers Bureau of the Ministry of Economic Affairs and Consumer Cooperatives -25- This paper Applicable to China National Standard (CNS) A4 (210X 297mm)

Claims (1)

Scope of Patent Application No. 87106265 Patent Application 1. A method for controlling a component separation system having a simulated moving bed, comprising a closed separation circuit composed of column beds connected in series with each other and containing an adsorbent material, which is divided by fluid injection and extraction points There are 2 areas, a device for injecting fluid into the circuit, a device for taking fluid out of the circuit, an injection point and take-out point conversion device sufficient to simulate the reverse replacement of the tower bed, and a device for measuring operating variables. : Again-measuring the unique variables of fluid injection and extraction at several points along the circuit and operating the unique variables of the separation system, Λ-from measuring the true value of the variables and using a non-linear mode of the separation system to determine each Do not indicate the ratio of the ratio (Rk), which is in each different area 'between the fluid flow rate (QK) and the simulated adsorbent material flow rate (Qs) to bring the control variable (ξ) to or back Determined settings =, and-From some ratios (Rk) determine the value to be given to the operating variable. 2. The method according to item 1 of the patent application scope, wherein the value of the given operating variable is determined using a non-linear mode of the separation system. 3. The method according to item 1 of the scope of patent application, where the given operating variable is printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs • — J ^-(Please read the precautions on the back before filling in this page y * 1T The value is determined using the linear mode of the separation system close to a given operating point. 4. The method according to item 1 or 3 of the scope of the patent application, wherein on the separation loop area containing an array of adjacent stages including the η region , Where η ratios (Rk) are defined, including m controlled variables (ξ) defined according to the flow value (D) and concentration value (X), whose claw value is less than or equal to 11 and determines the m (Rk) or the m combination of the ratio, which contains (n_m) reference paper sizes. Applicable to China National Standard (CNS) A4 specifications (210 x 297 degrees). 6. Patent application scope No. 87106265 Patent application Chinese application patent scope amendment too 1. A method for controlling a component separation system having a simulated moving bed, comprising a closed separation circuit composed of column beds connected in series with each other and containing an adsorbent material, which is divided by fluid injection and extraction points There are 2 areas, a device for injecting fluid into the circuit, a device for taking fluid out of the circuit, an injection point and take-out point conversion device sufficient to simulate the reverse replacement of the tower bed, and a device for measuring operating variables. : Again-measuring the unique variables of fluid injection and extraction at several points along the circuit and operating the unique variables of the separation system, Λ-from measuring the true value of the variables and using a non-linear mode of the separation system to determine each Do not indicate the ratio of the ratio (Rk), which is in each different area 'between the fluid flow rate (QK) and the simulated adsorbent material flow rate (Qs) to bring the control variable (ξ) to or back Determined settings =, and-From some ratios (Rk) determine the value to be given to the operating variable. 2. The method according to item 1 of the patent application scope, wherein the value of the given operating variable is determined using a non-linear mode of the separation system. 3. The method according to item 1 of the scope of patent application, where the given operating variable is printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs • — J ^-(Please read the precautions on the back before filling in this page y * 1T The value is determined using the linear mode of the separation system close to a given operating point. 4. The method according to item 1 or 3 of the scope of the patent application, wherein on the separation loop area containing an array of adjacent stages including the η region , Where η ratios (Rk) are defined, including m controlled variables (ξ) defined according to the flow value (D) and concentration value (X), whose claw value is less than or equal to 11 and determines the m (Rk) or the m combination of the ratio, which contains (n_m) reference paper sizes applicable to the Chinese National Standard (CNS) A4 specification (210 x 297 degrees) The method, in which the ratio (Rk) value is the knowledge model of the coupling and non-linear temperature line produced by the additional extraction point, M y.... Μ. Generalization (Lam Moore_Fuluoying Jialiqi Isotherm is used in the separation system 弋 simulation. 1 1 · According to the patent application Fanyuan No. 1 to 3 medium cup, T Shi-Xiang 弋 method, where In the separation circuit that includes a certain number of P regions, the value of the &lt; Tk &lt; ratio (Rk) is known and the ratio of the extra ratio of the owner produced by feeding at least one additional injection point in the separation circuit. Corresponding value 'is determined as a function of the ratio between the adjacent area and the injection flow value at the additional injection point. I2. According to any of the items 1 to 3 of the patent application park, the number of areas including a certain number of p is separated. Known in the circuit, the corresponding value of the additional ratio of feed at least one / ll ~ f ✓ I ^ in the separation circuit is determined as the ratio of the ratio in the adjacent area to the value of the extraction flow at the additional extraction point Function 13. Method according to item 8 of the patent application, where Select the ratio between the component concentrations in the fluid to be taken out as the controlled variable. 14. According to the method of any one of the scope of the patent application, an optimization algorithm is selected. 0 ^ The controlled variables are allowed to pass through a fixed order. 15. The method according to one of the aforementioned patent applications, which is applied to Gu Nu 'Λη —I »—…“ Erji, -3 This paper is applicable to the Chinese National Standard (CNS) A4 (210X297 mm) ) IT.— mn ^ — 1 m (n mu I. 1 nn nn--eJ (Please read the notes on the back before filling out this page) Employees' Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs printed an aroma with eight carbon atoms Printed by A8, Bδ, C8, D8, Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs 6. Number of patent applications. 5. The method according to item 2 of the patent application park, in which the On the separation loop area, η ratios (Rk) are defined, including m controlled variables (ξ) are defined according to the flow value (D) and concentration value (X), whose m value is less than or equal to the η value, measuring The concentration at the end of the segment is in the liquid phase and determines the ratio m (Rk) or the combination of the ratio m, which contains (nm) parameters. 6. According to any of the claims 1 to 3 in the scope of the patent application Method, wherein the operating variable is the flow rate and the valve transition period (T) can simulate the replacement of the tower bed. 7. The method according to any one of the claims 1 to 3, wherein the separation circuit includes Four main areas, and measured from the line of each concentration, simultaneously control, for example, the yield of the loop and the controlled variable (ξ) of the purity of at least one component of the mixture. 8. The method according to any one of claims 1 to 3, which includes concentration measurement by Raman-type online analysis, chromatographic analysis, or near-infrared (NIR) analysis. 9. The method according to any one of the claims 1 to 3, wherein, in the example of a separation system having four regions, at least one of the following four quantities is selected as the controlled variable: from The purity of the first component in the fluid taken out by the circuit, the yield of the component by the separation system, the tail of the first component behind the first of the four zones related to the circulation direction of the fluid, Or the tails of all the components except the first component are in front of the last of the four zones related to the circulation direction of the fluid. 10.According to the method of any one of items 1 to 3 of the scope of patent application, it is based on (CNS) A4 ^ (210X297, JiT * ~-^-(Please read the note on the back before filling this page). Order The method, in which the ratio (Rk) value is the knowledge model of the coupling and non-linear temperature line produced by the additional extraction point, M y.... Μ. Generalization (Lam Moore_Fuluoying Jialiqi Isotherm is used in the separation system 弋 simulation. 1 1 · According to the patent application Fanyuan No. 1 to 3 medium cup, T Shi-Xiang 弋 method, where In the separation circuit that includes a certain number of P regions, the value of the &lt; Tk &lt; ratio (Rk) is known and the ratio of the extra ratio of the owner produced by feeding at least one additional injection point in the separation circuit. Corresponding value 'is determined as a function of the ratio between the adjacent area and the injection flow value at the additional injection point. I2. According to any of the items 1 to 3 of the patent application park, the number of areas including a certain number of p is separated. Known in the circuit, the corresponding value of the additional ratio of feed at least one / ll ~ f ✓ I ^ in the separation circuit is determined as the ratio of the ratio in the adjacent area to the value of the extraction flow at the additional extraction point Function 13. Method according to item 8 of the patent application, where Select the ratio between the component concentrations in the fluid to be taken out as the controlled variable. 14. According to the method of any one of the scope of the patent application, an optimization algorithm is selected. 0 ^ The controlled variables are allowed to pass through a fixed order. 15. The method according to one of the aforementioned patent applications, which is applied to Gu Nu 'Λη —I »—…“ Erji, -3 This paper is applicable to the Chinese National Standard (CNS) A4 (210X297 mm) ) IT.— mn ^ — 1 m (n mu I. 1 nn nn--eJ (Please read the notes on the back before filling out this page) Employees' Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs printed an aroma with eight carbon atoms Separate