SOFTSENSOR FOR MORPHOLOGY OF POLYMERS

Abstract

A method of producing a soft sensor for a reference morphology of multiphase latex polymer particles synthesized in a production process is provided. The method is used in monitoring and/or controlling the production process. The method may also be used for optimizing production capacities of the production process.

Claims

1. A method of producing a soft sensor for a reference morphology of multiphase latex polymer particles synthesized in a production process, for use in monitoring and/or controlling the production process and/or optimizing production capacities of the production process, comprising: providing via an interface to a processing device; time series data from a reference polymerization process, a morphology functional, wherein the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster-formation along a reaction progression, in a reaction process, by relating a movement of polymer clusters in multiphase latex polymer particles since the instance of polymer cluster formation to time series data of a reaction process determining at the processing device a reference trajectory of the morphology functional up to a reference observation point along the reference reaction progression based on the time series data from the reference polymerization process, and the morphology functional, providing the soft sensor, the soft sensor comprising a reference trajectory of the morphology functional determined from the reference polymerization process, the morphology functional and a sensor input for receiving time series data from a production process of the multiphase latex polymer particles an output for a) the reference trajectory of the morphology functional and a production trajectory of the morphology functional for the production process or b) a deviation between the reference trajectory and the production trajectory.

2. The method of claim 1, wherein the time series data from the reference polymerization process comprises a temperature of a reference reactor, flowrates of each ingredient fed into the reference reactor, and wherein the time series data for the production process comprises a temperature of a production reactor and flowrates of each ingredient fed into the production reactor.

3. The method of claim 1, wherein the respective time series data comprises the respective initial amount of each ingredient fed into the reactor.

4. The method of claim 1, wherein the morphology functional depends on a quantity indicative of a polymer and/or monomer content inside the polymer matrix in the reaction process and a reaction progression variable and wherein the time series data comprises data suitable for determining the reaction progression variable of the production process, the quantity indicative of a polymer and/or monomer content inside the polymer matrix in the production process.

5. The method of claim 1, wherein the morphology functional comprises a cluster mobility function, describing a mobility of the polymer clusters in the latex polymer particles during progression of the reaction process.

6. The method of claim 5, wherein the cluster mobility function depends on the quantity indicative of a polymer and/or monomer content inside the polymer matrix in the reaction process.

7. The method of claim 1, wherein the cluster mobility function comprises a function of a particle matrix viscosity.

8. The method of claim 1, wherein the providing via an interface to a processing device the time series data of the reference polymerization process comprises providing the time series data via a client device, wherein the client device comprises a processing unit, and a client device communication interface for communication with the interface and/or receiving the soft sensor at a client device via an interface to a processing device time series data of the reference polymerization process comprises providing via a client device, wherein the client device comprises a processing unit, and a client device communication interface for receiving the soft sensor from the output interface.

9. A soft sensor produced according to claim 1 comprising: a reference trajectory of the morphology functional derived from a reference polymerization process, a morphology functional describing the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster formation along a reaction progression, in a reaction process, by relating a movement of polymer clusters in multiphase latex polymer particles since the instance of polymer cluster formation to time series data of a reaction process and a sensor input for receiving time series data from a production process of the multiphase latex polymer particles an output for the reference trajectory of the morphology functional and a production trajectory of the morphology functional for the production process.

10. A method for monitoring and/or controlling the morphology of multiphase latex polymer particles synthesized in a production process, comprising: providing to a soft sensor according to claim 9, time series data of the production process and determining the production trajectory of the morphology functional based on the morphology functional, wherein the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster formation along a reaction progression, in the reaction process, and the time series data from the production process, determining a monitoring and/or control signal associated with the determined production trajectory of the morphology functional, and the reference trajectory of the morphology functional. providing a monitoring and/or control signal via an output interface.

11. A method of optimizing capacity of a production process while maintaining a reference morphology, comprising: providing constraints to a processing device, providing the soft sensor according to claim 9, determining with the processing device an optimal production capacity, based on the constraints and the reference trajectory of the morphology functional, such that the reaction trajectory of the morphology functional matches the reference trajectory of the morphology functional.

12. A System for executing the method according to claim 1, comprising a processor an input interface and an output interface, wherein the processor is configured for performing the method.

13. A computer program product, that when run on a processing device performs the method according to claim 1.

14. A system comprising a monomer suitable for emulsion polymerization and the soft sensor according to claim 9.

Description

DESCRIPTION OF THE FIGURES

[0369] FIG. 1: illustrates a production reactor setup suitable for use in emulsion polymerization reactions.

[0370] FIG. 2 illustrates a reference reactor setup suitable for use in emulsion polymerization reactions.

[0371] FIG. 3 illustrates movement of a polymer cluster inside a particle during progression of a reaction.

[0372] FIG. 4 illustrates the workflow of the proposed method.

[0373] FIG. 5 illustrates the workflow of a suitable control algorithm

[0374] FIG. 6 illustrates a setup comprising the system for performing the control method and the connection to a setup for performing the reaction.

[0375] FIG. 7illustrates trajectories according to the disclosure

[0376] FIG. 8 illustrates movement of polymer clusters along the reaction progression

[0377] FIG. 9 illustrates a soft sensor according to the invention

[0378] FIG. 10 shows a distributed system for providing a soft sensor according to the invention

[0379] FIG. 11 shows an alternative setup for controlling

[0380] FIG. 12 shows a method of producing a soft sensor according to the invention

[0381] FIG. 13 shows a system for producing a soft sensor according to the invention

DETAILED DESCRIPTION

[0382] In FIG. 1 a production reactor setup 2000 suitable for use in emulsion polymerization reactions is depicted. A reactor 2100 is equipped with a cooling/heating jacket 2200, for heating and/or cooling the reactor. The cooling/heating jacket does have an inlet 2210 and an outlet 2230. The inlet of the cooling/heating jacket is provided with an inlet temperature sensor 2220, that measures the inlet temperature (T.sub.jacket,in). The outlet of the cooling/heating jacket is provided with an outlet temperature sensor 2240, that measures the outlet temperature (T.sub.jacket,out). The inlet of the cooling/heating jacket is equipped with an actuator 2250 for manipulating the flowrate of the cooling medium in the cooling/heating jacket and a flow sensor 2255 for measuring that flowrate. In another example not shown, there can be more than one cooling/heating jackets. In further examples cooling and heating may be performed by one or more separate devices. The reactor is further equipped with a temperature sensor 2650 for measuring the reaction temperature in the reactor. The reactor is equipped with three ingredient feedlines 2300, 2400, 2500. In this example feedline 2300 is for feeding a first monomer, feedline 2400 is for feeding a second monomer and feedline 2500 is for feeding an initiator. Each of the feedlines is provided with a respective flow sensor 2310, 2410 and 2510 a respective temperature sensor 2330, 2430, 2530 and a respective actuator 2320, 2420, 2520 for manipulating the respective flowrate. The first to digits of the flow sensors, the temperature sensors and the actuators refer to the corresponding feedline.

[0383] In FIG. 2 a reference reactor system 3000 similar the reactor system in FIG. 1 is shown. Numbers start at 3000 and items corresponding to items in FIG. 1 use the same last three digits as in FIG. 1.

[0384] The reactor is further equipped with a temperature sensor 3650 for measuring the reaction temperature in the reactor. The reactor is equipped with three ingredient feedlines 3300, 3400, 3500. In this example feedline 3300 is for feeding a first monomer, feedline 3400 is for feeding a second monomer and feedline 3500 is for feeding an initiator. Each of the feedlines is provided with a respective flow sensor 3310, 3410 and 3510 a respective temperature sensor 3330, 3430, 3530 and a respective actuator 3320, 3420, 3520 for manipulating the respective flowrate. The first to digits of the flow sensors, the temperature sensors and the actuators refer to the corresponding feedline.

[0385] FIG. 3 illustrates how the morphology of a polymer particle 10 depends on movement of polymer clusters. A polymer cluster 20 formed at a time t=0 will in this illustration migrate to a final position at the end of the polymer reaction t=t.sub.f. The final position of the polymer cluster would lead to a raspberry like structure of the polymer particle. For illustration purposes only one polymer cluster is formed at t=0 although typically a larger number of polymer clusters may be formed at each time during the reaction process. Therefore, when discussing a polymer cluster formed at a specific point in time it is generally referred to all polymer clusters formed at that specific time and the movement may be a mean movement considering all polymer clusters formed at that specific time. FIG. 3 also neglects that new polymer clusters may be formed during any point of the reaction progression.

[0386] In FIG. 4 the method of controlling is illustrated in a non-limiting example.

[0387] In this example a first monomer and a second monomer are used. An initiator is also used. The selection of monomer and initiator is for illustration purposes only and should not be construed as limiting. The method is applicable for other combinations of monomers and initiators alike.

[0388] At step 100 time series data from a reference polymerization process, suitable for determining [0389] the reaction progression variable [0390] a quantity indicative of the polymer or monomer content inside the polymer particles in the reference polymerization process, is provided to processor 4200.

[0391] The time series data from the reference polymerization process comprises the temperature of the reactor. In this example the reaction temperature (T) in the reactor is measured by the temperature sensor 3250 in the reactor 3100; [0392] The cooling/heating jacket temperature; the inlet and outlet temperatures are measured in this example by the temperature sensors 3220 and 3240 respectively; [0393] The flowrates of each ingredient fed into the reactor comprises measured data from the flow sensors for each of the type of monomers 3310, 3410 and the initiator 3510 throughout the entire course of the polymerization: ∀.sub.i, F.sub.i(t), 0 ≤ t ≤ t.sub.end. Wherein Fi is the flow rate for each ingredient and i is an index for each type of ingredient; un this example the indices are assigned as follows (i= 1: first monomer; i=2: second monomer; i=3: initiator); [0394] The temperature of the feeds measured by temperature sensors 3330, 3430 and 3530; [0395] the initial amount of each ingredient in the reactor comprises the initial amount of a first monomer, an initial amount a second monomer and an initial amount of the initiator; [0396] the flowrate of the cooling medium in the cooling/heating jacket measured by flow sensor 3255.

[0397] From these time series data the quantity indicative of the amount of polymerized monomers in the reaction process is determined at optional step 200.

[0398] The amount of heat produced by polymerization (Q) is then determined by means of the heat balance in the reactor using equation (2)

[0399] The mass flow of each ingredient is provided to the processor from the flow sensors 2310, 2410, 2510.

[0400] The amount of monomer converted to polymer may then be determined as

[00026]$\left\{Molesofmonomerpolymerized\right\}=\frac{1}{\text{Δ}{{\rm H}}_{pol}}{\displaystyle {\int }_0^t\dot{Q}d{t}^{\prime }}$

[0401] Wherein ΔH.sub.pol is the enthalpy of the polymerization reaction. If more than one type of monomers is used, data indicative of the amount of each monomer i polymerized (M.sub.i,polymerized) and the amount of polymer can be obtained by using a modification of equation (3) as described in literature[Gugliotta, L.M., Arotçarena M., Leiza, J.R., Asua, J.M. Estimation of conversion and copolymer composition in semi-continuous emulsion polymerization using calorimetric data, Polymer, 1995, 36, 2019-2013].

[0402] At optional step 300 the quantity indicative of the polymer or monomer content inside the polymer matrix in the reference reaction process is determined. In this example it is derived from the quantity indicative of the amount of monomer converted to polymer. In this example the assumption that the whole amount of monomer converted to polymer is inside the particles and that the remaining amount of unreacted monomer is also inside the particles is used. In this example, the volume fraction of polymer in the polymer particles can then be determined using the relation

[00027]$\begin{array}{l}{\text{ϕ}}_{pol}\left(t\right)\approx \\ \frac{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}}{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}+\frac{\left\{Massofunreactedmonomers\right\}}{\left\{Densityofmonomers\right\}}}\end{array}$

[0403] In this example it is assumed to be the quantity indicative of the polymer content inside the polymer matrix.

[0404] Step 400 is again optional, here time series data from a production process, suitable for determining [0405] a reaction progression parameter and [0406] a quantity indicative of the polymer or monomer content inside the polymer particles in the production reaction process, are provided to the processor.

[0407] The time series data from the reference polymerization process comprises: [0408] the temperature of the reactor 3100. In this example the reaction temperature (T) in the reactor is measured by the temperature sensor 3250 in the reactor 3100; [0409] The cooling/heating jacket temperature; the inlet and outlet temperatures are measured in this example by the temperature sensors 3220 and 3240 respectively; [0410] The flowrates of each ingredient fed into the reactor comprises measured data from the flow sensors for each of the type of monomers 3310, 3410 and the initiator 3510 throughout the entire course of the polymerization: ∀.sub.i, F.sub.i(t), 0 ≤ t ≤ t.sub.end. Wherein Fi is the flow rate for each ingredient and i is an index for each type of ingredient; un this example the indices are assigned as follows (i= 1: first monomer; i=2: second monomer; i=3: initiator); [0411] The temperature of the feeds measured by temperature sensors 3330, 3430 and 3530; [0412] the initial amount of each ingredient in the reactor comprises the initial amount of a first monomer, an initial amount a second monomer and an initial amount of the initiator; [0413] the flowrate of the cooling medium in the cooling/heating jacket measured by flow sensor 3255.

[0414] From these time series data the quantity indicative of the amount of polymerized monomers in the reaction process is determined at optional step 500.

[0415] The amount of heat produced by polymerization (Q) is then determined by means of the heat balance in the reactor using equation (2)

[00028]$m_R{c}_{pR}\frac{dT}{dt}=\dot{Q}+{\displaystyle \underset{i}{.Math.}{F}_i{c}_{pi}\left(T_i-T\right)-{\dot{Q}}_j}$

[0416] Wherein m.sub.R and c.sub.pR are the mass and the specific heat capacity of the reactor and F.sub.i and c.sub.pi the mass flow and specific heat capacity of ingredient i that is fed to the reactor at a temperature T.sub.i. The mass flow of each ingredient is provided to the processor from the flow sensors 3310, 3410, 3510.

[0417] The amount of monomer converted to polymer may then be determined as

[00029]$\left\{Molesofmonomerpolymerized\right\}=\frac{1}{\text{Δ}{{\rm H}}_{pol}}{\displaystyle {\int }_0^t\dot{Q}d{t}^{\prime }}$

[0418] Wherein ΔH.sub.pol is the enthalpy of the polymerization reaction. If more than one type of monomers is used, data indicative of the amount of each monomer i polymerized (M.sub.i,polymerized) and the amount of polymer can be obtained by using a modification of equation (3) as described in literature [Gugliotta, L.M., Arotçarena M., Leiza, J.R., Asua, J.M. Estimation of conversion and copolymer composition in semicontinuous emulsion polymerization using calorimetric data, Polymer, 1995, 36, 2019-2013].

[0419] At optional step 600 the quantity indicative of the polymer or monomer content inside the polymer particles in the production reaction process is determined. In this example it is derived from the quantity indicative of the amount of monomer converted to polymer. In this example the assumption that the whole amount of monomer converted to polymer is inside the particles and that the remaining amount of unreacted monomer is also inside the particles is used. In this example, the volume fraction of polymer in the polymer particles can then be determined using the relation

[00030]$\begin{array}{l}{\text{ϕ}}_{pol}\left(t\right)\approx \\ \frac{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}}{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}+\frac{\left\{Massofunreactedmonomers\right\}}{\left\{Densityofmonomers\right\}}}\end{array}$

[0420] In this example it is assumed to be the quantity indicative of the polymer content inside the polymer matrix.

[0421] At step 700 the morphology functional is provided to the processor, wherein the morphology functional maps the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster-formation along a reaction progression in a reaction process, the morphology functional depending on the time series data, suitable for determining a quantity indicative of the amount of polymerized monomers in the reaction process, a quantity indicative of the polymer or monomer content inside the polymer particles in the reaction process and a reaction progression variable in this example the reaction progression variable is the overall monomer X.sub.overall.

[0422] In this example the morphology functional depends on the conditions inside the polymer particle. This dependency is in this example described by the cluster mobility function (Ψ). Therefore, in this example the morphology functional relationship comprises the cluster mobility function. The cluster mobility function describes the mobility in the polymer particles during progression of the reaction process.

[0423] In an example the cluster mobility function depends on the data indicative of the reaction temperature, the quantity indicative of monomer or polymer content inside the polymer matrix and the glass transition temperature (T.sub.g) and the molar mass (M.sub.w) of the seed polymer. In this example the cluster mobility function is considered to be the matrix viscosity (η).

[00031]$\text{ψ}=\frac{1}{\eta \left({\varphi }_{pol},T,T_g,M_w\right)}$

[0424] The morphology functional (Y) in this example is a functional that depends on the cluster mobility function (Ψ) and X.sub.overall; Y=f(Ψ,X.sub.overall).

[0425] In this example the, the particle matrix viscosity is described as:

[00032]$\begin{array}{cc}\left(\eta \left({\varphi }_{pol},T,T_g,M_w\right)=A{\varphi }_{pol}^n\text{exp}\left(B\frac{{{\rm T}}_{g,eff}}{T}-C\right)\right)& \text{­­­(9)}\end{array}$

[0426] Wherein T.sub.g,eff is the effective glass transition temperature, and A, n, B and C are parameters that can be experimentally determined. Ways of determining T.sub.g,eff and the parameters are disclosed in Properties of Polymers by D. W. van Krevelen, Klaas te Nijenhuis, 4.sup.th edition, Elsevier Science, 2009. In this example, the effect of the molar mass of the seed is included in the parameters. In an alternative example a relative matrix viscosity is used (η.sub.rel).

[0427] At optional step 800 as an actual value input signal the production trajectory of the morphology functional up to a recent observation point along the production reaction progression based on the time series data from a production process, and the production reaction progression variable is determined.

[0428] At step 900 as a setpoint value the reference trajectory of the morphology functional up to a reference observation point along the production reaction progression based on [0429] the time series data from the reference polymerization process, [0430] and the reference reaction progression variable is determined.

[0431] At optional step 1000, the setpoint value and the actual value input signal a provided to a control algorithm, wherein the control algorithm determines a value for manipulated variables based on the setpoint value and the actual value input signal.

[0432] The optional steps of a suitable control algorithm are shown in FIG. 5.

[0433] At optional step 1100, the setpoint value and the actual value input signal are received by the control algorithm.

[0434] At step 1200 a predicted production trajectory of the morphology functional is determined based on the production trajectory of the morphology functional at the recent observation point, the morphology functional and the reference observation point.

[0435] In step 1300 the future reaction conditions expressed as the time evolutions of the amount of unreacted monomers (or equivalently the instantaneous monomer conversion X.sub.inst), overall monomer conversion and temperature may be determined as

[00033]$\begin{array}{l}\underset{X_{\text{inst}}\left(t\right),X{}_{\text{overall}}\left(t\right),T\left(t\right)}{\text{min}}\left[{\displaystyle {\int }_0^{X{}_{\text{overall,PH}}}W}\left(X{}_{\text{overall,F}}\right)\right)\\ \left({\left(Y_{\text{ψ,}X{}_{\text{overall,PH}}}^{\text{prod}}\left(X{}_{\text{overall,F}}\right)-Y_{\text{ψ,}X{}_{\text{overall,PH}}}^{\text{ref}}\left(X_{\text{overall,F}}\right)\right)}^{2}d{X}_{\text{overall,F}}\right]\end{array}$

wherein W is a weighing function that may be used to give more importance to certain parts of the trajectory. In an aspect, W(X.sub.overall,F) = 1, for all X.sub.overall,F,

[0436] This determines the production trajectory of the morphology functional with the least deviation from the reference trajectory of the morphology functional. In terms of control, the difference between the recent observation point and the reference observation point is the prediction horizon.

[0437] At step 1400, X.sub.inst(t), X.sub.overall(t), T(t) are controlled by varying the feed rates of the ingredients of the formulation (monomers, initiators), and the inlet temperature and/or the flow rate of the cooling/heating fluid.

[0438] At step 1500 control signals are provided to manipulate the flow rates and the temperatures accordingly.

[0439] FIG. 6 is an illustration for a suitable system 4000.

[0440] The system comprises the processor 4200 to which data is provided. An interface 4100 receives the morphology functional from a database 4500. The time series data from the reference polymerization process are also provided from the database. The time series data for the reference polymerization process, the morphology functional provided to the processor via the interface 4100.

[0441] The time series data from the production process are provided from the production process system 2000 to an interface. In this example interface 4100. In other examples various different interfaces may be used. The time series data from the production process are provided to the processor via the interface.

[0442] The processor in this example also comprises the control algorithm 4400 and is located in the processor. In other examples the control algorithm may be hosted in a separate device.

[0443] The control algorithm provides control signals to the production system. 4300 depicts an input/output device for monitoring and inputting data. The prediction horizon may in an example be provided by the input/output device.

[0444] FIG. 7 illustrates trajectories along a reaction progression, the coordinate for reaction progression may be time or overall monomer conversion. In this example the reaction progression coordinate is overall monomer conversion. The advantage of this way of presenting the trajectories is that they can be used for processes where the polymerization rate is different from that of the reference polymerization process. Therefore, they represent an “universal” soft sensor which can be used as set points for any process. A selection of five trajectories is shown. Each trajectory crosses the reaction progression axis at a different point. Trajectory 5100 crosses the reaction progression axis at an end point of the reaction progression named final. For any instance along the reaction progression a respective trajectory may be calculated and provided to the output device. Each of trajectories containing the information of the movement of all polymer clusters in the multiphase latex polymer particles created up to an observation point on the reaction progression axis.

[0445] FIG. 8 illustrates the movement of polymer clusters created at different times during reaction progression. In FIG. 8a polymer clusters 6000 formed at the beginning of the reaction progression are represented as triangle. As these polymer clusters 6000 where just formed, no movement of the polymer clusters within the multiphase latex polymer particles occurred. At reaction progression of X.sub.m new polymer clusters 6100 are formed, represented as a circle (FIG. 8b). One can see that polymer clusters 6000 moved to point Y.sub.m*, while the newly formed polymer clusters 6100 did not move. At the final point of the reaction polymer clusters 6200 are formed (FIG. 8c). All previously formed polymer clusters will have moved according to their respective instance of formation. Exemplarily depicted as polymer clusters 6000, polymer clusters 6100 and polymer clusters 6200. Polymer clusters are produced continuously throughout the emulsion polymerization process; therefore, it is clear that this illustration only arbitrarily describes the movement for selected polymer clusters 6000, 6100, 6200. A specific trajectory represents the movement of all polymer clusters in multiphase latex polymer particles since their instance of formation along a reaction progression, in the reaction process until the observation point, which would be the point where the specific crosses the reaction progression axis.

[0446] FIG. 9 illustrates a soft sensor 7000 according to the invention. The soft sensor comprises an input 7100, for receiving time series data from a production process, wherein in this example the time series data from the production process comprise a temperature of the production reactor, flowrates of each of two ingredients fed into the production reactor. Further in this example the time series data may comprise data suitable for determining the reaction progression variable of the production process, the quantity indicative of a polymer and/or monomer content inside the polymer matrix in the production process. In this example, the time series data comprises the temperatures at an inlet of a heating/cooling jacket and the outlet of a heating/cooling jacket. This allows to determine the heat transfer during the reaction. The soft sensor further comprises a morphology functional 7200, wherein the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster formation along a reaction progression, in a reaction process, an output interface for 7400 for providing a reaction trajectory of the morphology functional. The soft sensor further comprises a reference trajectory of the morphology functional 7300. The reference trajectory of the morphology functional is derived from a historic polymerization process, leading to a desired morphology of the latex polymer particles. The soft sensor further comprises an output 7500 for providing the reference trajectory of the morphology functional. The soft sensor may be coupled to a processing device that determines the production trajectory of the morphology functional based on the received measured time series data of the production process. The soft sensor may be used for monitoring/ and or controlling the reaction process. The soft sensor may further be used for optimizing capacity of a reaction process. In an alternative, the soft sensor may comprise a single output for a deviation between the reference trajectory and the production trajectory.

[0447] FIG. 10 shows a distributed system 8000 for distributing a soft sensor. A client device 8200 comprising a processing unit 8210 and a client device communication interface 8250.

[0448] The system further comprises a system 8100 for providing a soft sensor, the system 8100 comprises a database 8300 for providing a morphology functional, wherein the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster-formation along a reaction progression, in a reaction process to a processor 8110. The database is in communication with an interface 8150 of the system 8300. Interface 8150 is further in communication with the client device communication interface. Time series data from a reference reaction process can be provided to the system 8300 via the communication interface 8250 to the interface 8150. The processor 8110 is configured for determining a reference trajectory of the morphology functional up to a reference observation point along the reference reaction progression based on time series data from the reference polymerization process, and the morphology functional. System 8100 further comprises an output interface 8130 for providing a soft sensor, the soft sensor comprising the reference trajectory of the morphology functional, the morphology functional and an input for receiving time series data from a production process. The soft sensor can then be received at the client device communication interface. In this example, system 8100 is a server, in particular a cloud server and the communication between the client device and the system is performed via a network. In other examples, the client device may be integrated into the system 8100. In one example, the soft sensor is part of a system comprising a monomer and the soft sensor. In that case tag associated with the monomer may be provided. The tag may be a computer readable tag, or an access code. The soft sensor may then be received by downloading the soft sensor to a client device. The download may be triggered using the tag. In such a case the tag is validated on system 8100, upon validation providing of the soft sensor is released. This may be by downloading the soft sensor to the client device.

[0449] FIG. 11 shows an alternative system for controlling production of a polymer.

[0450] The system comprises a production reactor as disclosed in FIG. 1, providing measurement signals to the soft sensor 7000 described with reference to FIG. 9. Reference numbers corresponding to figures share the same reference numbers. The system further comprises a controller unit 15000. The controller unit comprises inputs 15100 for signals provided from the soft sensor, outputs 15200 for controlling the production reactor. The controller unit further comprises a processing device for determining control signals based on signals from the soft sensor.

[0451] The input 15100 of the controller is connected to the output of the soft sensor 7500, 7400. The outputs of the controller are connected to actuators of the production reactor 2000, such that the production process may be controlled. The input of the soft sensor 7100 is connected to sensor signals of the production reactor. In FIG. 13 only some sensors from the production reactor are connected to the sensor inputs. This is for illustration purposes only, depicting all connections would render the figure unreadable.

[0452] In a first step, time series data of the production process are provided from the sensors of the production reactor to the soft sensor, the time series data comprising at least a temperature of the production reactor, and flowrates of each ingredient fed into the production, at the soft sensor the production trajectory of the morphology functional is determined based on the time series data and morphology functional, wherein the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster formation along a reaction progression, in the reaction process, The step of determining the production trajectory of the morphology functional works similar to the process described in FIG. 12 or with reference to FIG. 4 or the general description of determining a reaction trajectory of the morphology functional. The production trajectory of the morphology functional determined based on the morphology functional up to a recent observation point along the production reaction progression variable and on the time series data from a production process, may be understood as actual value input signal

[0453] The reference trajectory of the morphology functional and the production trajectory of the morphology functional are provided to the controller unit. In the controller unit, a setpoint value associated with the reference trajectory of the morphology functional up to a reference observation point along the production reaction progression based on the time series data from the reference polymerization process, and the reference reaction progression variable is determined. The reference observation point observation point along the production reaction progression based on the time series data from the reference polymerization process, and the reference reaction progression variable may be related to a production observation point along the production reaction progression based on the time series data from the production process. The setpoint value and actual value are provided to a control algorithm, wherein the control algorithm determines a value for manipulated variables based on the setpoint value and actual value.

[0454] In the controller unit a predicted production trajectory of the morphology functional is determined based on the production trajectory of the morphology functional at the recent observation point, the morphology functional and the reference observation point. The future reaction conditions expressed as the time evolutions of the amount of unreacted monomers (or equivalently the instantaneous monomer conversion X.sub.inst), overall monomer conversion and temperature may be determined as

[00034]$\begin{array}{l}\underset{X_{\text{inst}}\left(t\right),X{}_{\text{overall}}\left(t\right),T\left(t\right)}{\text{min}}\left[{\displaystyle {\int }_0^{X{}_{\text{overall,PH}}}W}\left(X{}_{\text{overall,F}}\right)\right)\\ \left({\left(Y_{\text{ψ,}X{}_{\text{overall,PH}}}^{\text{prod}}\left(X{}_{\text{overall,F}}\right)-Y_{\text{ψ,}X{}_{\text{overall,PH}}}^{\text{ref}}\left(X_{\text{overall,F}}\right)\right)}^{2}d{X}_{\text{overall,F}}\right]\end{array}$

wherein W is a weighing function that may be used to give more importance to certain parts of the trajectory. In an aspect, W(X.sub.overall,F) = 1, for all X.sub.overall,F,

[0455] This determines the production trajectory of the morphology functional with the least deviation from the reference trajectory of the morphology functional. In terms of control, the difference between the recent observation point and the reference observation point is the prediction horizon.

[0456] Then, X.sub.inst(t), X.sub.overall(t), T(t) are controlled by varying the feed rates of the ingredients of the formulation (monomers, initiators), and the inlet temperature and/or the flow rate of the cooling/heating fluid.

[0457] The control signals are provided via output 15200 to manipulate the flow rates and the temperatures accordingly.

[0458] FIG. 12 shows a method of producing a soft sensor according to the invention

[0459] In this example a first monomer and a second monomer are used. An initiator is also used. The selection of monomer and initiator is for illustration purposes only and should not be construed as limiting. The method is applicable for other combinations of monomers and initiators alike. Elements referring to the reference reactor are denominated according to FIG. 2.

[0460] At step 10000 time series data from a reference polymerization process, suitable for determining [0461] the reaction progression variable [0462] a quantity indicative of the polymer or monomer content inside the polymer particles in the reference polymerization process, is provided to a processor.

[0463] The time series data from the reference polymerization process comprises the temperature of the reactor. In this example the reaction temperature (T) in the reactor is measured by the temperature sensor 3250 in the reactor 3100; [0464] The cooling/heating jacket temperature; the inlet and outlet temperatures are measured in this example by the temperature sensors 3220 and 3240 respectively; [0465] The flowrates of each ingredient fed into the reactor comprises measured data from the flow sensors for each of the type of monomers 3310, 3410 and the initiator 3510 throughout the entire course of the polymerization: ∀.sub.i, F.sub.i(t), 0 ≤ t ≤ t.sub.end. Wherein Fi is the flow rate for each ingredient and i is an index for each type of ingredient; un this example the indices are assigned as follows (i= 1: first monomer; i=2: second monomer; i=3: initiator); [0466] The temperature of the feeds measured by temperature sensors 3330, 3430 and 3530; the initial amount of each ingredient in the reactor comprises the initial amount of a first monomer, an initial amount a second monomer and an initial amount of the initiator; [0467] the flowrate of the cooling medium in the cooling/heating jacket measured by flow sensor 3255.

[0468] From these time series data the quantity indicative of the amount of polymerized monomers in the reaction process is determined at optional step 20000.

[0469] The amount of heat produced by polymerization (Q) is then determined by means of the heat balance in the reactor using equation (2)

[0470] The mass flow of each ingredient is provided to the processor from the flow sensors 3310, 3410, 3510.

[0471] The amount of monomer converted to polymer may then be determined as

[00035]$\left\{Molesofmonomerpolymerized\right\}=\frac{1}{\text{Δ}{{\rm H}}_{pol}}{\displaystyle {\int }_0^t\dot{Q}d{t}^{\prime }}$

[0472] Wherein ΔH.sub.pol is the enthalpy of the polymerization reaction. If more than one type of monomers is used, data indicative of the amount of each monomer i polymerized (M.sub.i,.sub.polymerized) and the amount of polymer can be obtained by using a modification of equation (3) as described in literature[Gugliotta, L.M., Arotçarena M., Leiza, J.R., Asua, J.M. Estimation of conversion and copolymer composition in semi-continuous emulsion polymerization using calorimetric data, Polymer, 1995, 36, 2019-2013].

[0473] At optional step 30000 the quantity indicative of the polymer or monomer content inside the polymer matrix in the reference reaction process is determined. In this example it is derived from the quantity indicative of the amount of monomer converted to polymer. In this example the assumption that the whole amount of monomer converted to polymer is inside the particles and that the remaining amount of unreacted monomer is also inside the particles is used. In this example, the volume fraction of polymer in the polymer particles can then be determined using the relation

[00036]$\begin{array}{l}{\text{ϕ}}_{pol}\left(t\right)\approx \\ \frac{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}}{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}+\frac{\left\{Massofunreactedmonomers\right\}}{\left\{Densityofmonomers\right\}}}\end{array}$

[0474] In this example it is assumed to be the quantity indicative of the polymer content inside the polymer matrix.

[0475] The time series data from the reference polymerization process comprises: [0476] the temperature of the reactor 3100. In this example the reaction temperature (T) in the reactor is measured by the temperature sensor 3250 in the reactor 3100; [0477] The cooling/heating jacket temperature; the inlet and outlet temperatures are measured in this example by the temperature sensors 3220 and 3240 respectively; [0478] The flowrates of each ingredient fed into the reactor comprises measured data from the flow sensors for each of the type of monomers 3310, 3410 and the initiator 3510 throughout the entire course of the polymerization: ∀.sub.i,F.sub.i(t), 0 ≤ t ≤ t.sub.end. Wherein Fi is the flow rate for each ingredient and i is an index for each type of ingredient; un this example the indices are assigned as follows (i= 1: first monomer; i=2: second monomer; i=3: initiator); [0479] The temperature of the feeds measured by temperature sensors 3330, 3430 and 3530; [0480] the initial amount of each ingredient in the reactor comprises the initial amount of a first monomer, an initial amount a second monomer and an initial amount of the initiator; [0481] the flowrate of the cooling medium in the cooling/heating jacket measured by flow sensor 3255.

[0482] From these time series data the quantity indicative of the amount of polymerized monomers in the reaction process is determined at optional step 40000.

[0483] The amount of heat produced by polymerization (Q) is then determined by means of the heat balance in the reactor using equation (2)

[00037]$m_R{c}_{pR}\frac{dT}{dt}=\dot{Q}+{\displaystyle \underset{i}{.Math.}{F}_i{c}_{pi}\left(T_i-T\right)-{\dot{Q}}_j}$

[0484] Wherein m.sub.R and c.sub.pR are the mass and the specific heat capacity of the reactor and F.sub.i and c.sub.pi the mass flow and specific heat capacity of ingredient i that is fed to the reactor at a temperature T.sub.i. The mass flow of each ingredient is provided to the processor from the flow sensors 3310, 3410, 3510.

[0485] The amount of monomer converted to polymer may then be determined as

[00038]$\left\{Molesofmonomerpolymerized\right\}=\frac{1}{\Delta H_{pol}}{\displaystyle {\int }_0^t\dot{Q}d{t}^{\prime }}$

[0486] Wherein ΔH.sub.pol is the enthalpy of the polymerization reaction. If more than one type of monomers is used, data indicative of the amount of each monomer i polymerized (M.sub.i,.sub.polymerized) and the amount of polymer can be obtained.

[0487] At optional step 50000 the quantity indicative of the polymer or monomer content inside the polymer particles in the production reaction process is determined. In this example it is derived from the quantity indicative of the amount of monomer converted to polymer. In this example the assumption that the whole amount of monomer converted to polymer is inside the particles and that the remaining amount of unreacted monomer is also inside the particles is used. In this example, the volume fraction of polymer in the polymer particles can then be determined using the relation

[00039]$\begin{array}{l}{\text{ϕ}}_{pol}\left(t\right)\approx \\ \frac{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}}{\frac{\left\{Massofmonomerspolymerized\right\}}{\left\{Densityofpolymer\right\}}+\frac{\left\{Massofseed\right\}}{\left\{Densityofseed\right\}}+\frac{\left\{Massofunreactedmonomers\right\}}{\left\{Densityofmonomers\right\}}}\end{array}$

[0488] In this example it is assumed to be the quantity indicative of the polymer content inside the polymer matrix.

[0489] At step 60000 the morphology functional is provided to the processor, wherein the morphology functional maps the morphology functional describes the movement of polymer clusters in multiphase latex polymer particles since the instance of the polymer cluster formation along a reaction progression in a reaction process, the morphology functional depending on the time series data, suitable for determining a quantity indicative of the amount of polymerized monomers in the reaction process, a quantity indicative of the polymer or monomer content inside the polymer particles in the reaction process and a reaction progression variable in this example the reaction progression variable is the overall monomer X.sub.overall.

[0490] In this example the morphology functional depends on the conditions inside the polymer particle. This dependency is in this example described by the cluster mobility function (ψ). Therefore, in this example the morphology functional relationship comprises the cluster mobility function. The cluster mobility function describes the mobility in the polymer particles during progression of the reaction process.

[0491] In an example the cluster mobility function depends on the data indicative of the reaction temperature, the quantity indicative of monomer or polymer content inside the polymer matrix and the glass transition temperature (T.sub.g) and the molar mass (M.sub.w) of the seed polymer. In this example the cluster mobility function is considered to be the matrix viscosity (η).

[00040]$\text{Ψ=}\frac{1}{\eta \left({\varphi }_{pol},T,T_g,M_w\right)}$

[0492] The morphology functional (Y) in this example is a functional that depends on the cluster mobility function (ψ) and X.sub.overall; Y=f(ψ,X.sub.overall).

[0493] In this example the, the particle matrix viscosity is described as:

[00041]$\begin{array}{cc}\eta \left({\varphi }_{pol},T,T_g,M_w\right)=A{\varphi }_{pol}^n\text{exp}\left(\left(B\frac{T_{g,eff}}{T}-C\right)\right)& \text{­­­(9)}\end{array}$

[0494] Wherein T.sub.g,eff is the effective glass transition temperature, and A, n, B and C are parameters that can be experimentally determined. Ways of determining T.sub.g,eff and the parameters are disclosed in Properties of Polymers by D. W. van Krevelen, Klaas te Nijenhuis, 4.sup.th edition, Elsevier Science, 2009. In this example, the effect of the molar mass of the seed is included in the parameters. In an alternative example a relative matrix viscosity is used (η.sub.rel).

[0495] At step 70000, at the processing device a reference trajectory of the morphology functional up to a reference observation point along the reference reaction progression based on the time series data from the reference polymerization process and the morphology functional is determined. In this example, the reference trajectory of the morphology functional is determined, by

[00042]$\left(\text{Ψ,}{X}_{\text{overall,F}},X_{\text{overall,O}}\right)={\displaystyle {\int }_{X_{\text{overall,F}}}^{X_{\text{overall,O}}}\text{Ψ}}\left(\frac{M_M}{r_{p}V}\right)d{X}_{\text{overall}},$

based on the time series data from the reference polymerization process.

[0496] At step 80000 the produced soft sensor is provided, the soft sensor comprising the reference trajectory of the morphology functional, the morphology functional and an input for receiving time series data from a production process of the multiphase latex polymer particles, the time series comprising temperature of a production reactor and flowrates of each ingredient fed into the production reactor and an initial amount of the monomers of the production process an output for the reference trajectory of the morphology functional and a production trajectory of the morphology functional for the production process.

[0497] In FIG. 13 a system 11000 for producing a soft sensor is shown. In this example a database 11500 stores the time series data from a reference polymerization process. The time series data from the reference process may have been collected from a reference polymerization process in a reference reactor 3000. The data are then provided via interface to the processing device 11700. In this example the morphology functional is provided from the same database. In other examples the data bases may be different from each other. The soft sensor is then provided via output 11800.