Controllability Evaluation for Reactive Distillation Columns with

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Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane Kejin Huang, Yang Yuan, Xinxiang Zang, Haisheng Chen, Liang Zhang, Xing Qian, and Shaofeng Wang Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.7b03666 • Publication Date (Web): 08 Jan 2018 Downloaded from http://pubs.acs.org on January 9, 2018

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Industrial & Engineering Chemistry Research

Research note submitted to Industrial & Engineering Chemistry Research

Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane

Kejin Huang∗, Yang Yuan, Xinxiang Zang, Haisheng Chen, Liang Zhang, Xing Qian, and Shaofeng Wang College of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China

∗

Phone: +86–10–64437805. Fax: +86–10–64437805. E-mail: [email protected]. 1

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ABSTRACT: In our recent work, the arrangement of multiple reactive sections is found to greatly enhance the steady-state performance of reactive distillation columns disproportionating trichlorosilane to silane. In the current research, process dynamics and controllability are studied through in-depth comparative analysis of open-loop and closed-loop behaviors between three reactive distillation columns with, respectively, a single reactive section (RDC-SRS), double reactive sections (RDC-DRS), and triple reactive sections (RDC-TRS). In the regulation path, although the arrangement of double and triple reactive sections reduces slightly the process gains between the bottom product composition and reboiler heat duty in the RDC-DRS and RDC-TRS, it helps to alleviate the coupling between the bottom product composition and reflux flow rate, thereby gaining increases in process controllability as compared with the RDC-SRS. In the disturbance path, the arrangement of double and triple reactive sections results in no intensified sensitivities to the disturbances from feed flow rate and composition. The closed-loop operation tests coincide with the open-loop analysis and demonstrate that the RDC-TRS and RDC-DRS exhibit substantially improved anti-disturbance and set-point tracking capabilities as compared with the RDC-SRS. These outcomes highlight evidently the great importance of arranging multiple reactive sections to the dynamics and controllability of reactive distillation columns separating reacting mixtures with unfavorable and complicated reaction kinetics.

Keywords:

Reactive distillation, Multiple reactive sections, Process design, Process dynamics, Process control

2


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1.

INTRODUCTION The performance of a reactive distillation column depends heavily on the combination between the reaction operation and

separation operation involved. 1-4 Among the structural variables that affect the combination, the number of reactive sections is considered to be the most important decision variable in process synthesis and design. The conventional design strategy overlooks totally its effects and leads to a reactive distillation column with a single reactive section (RDC-SRS). Although the RDC-SRS is economically advantageous over its conventional counterpart in the separations of reacting mixtures with favorable thermodynamics (e.g., A + B ↔ C + D with αC > αA > αB > αD), it is usually unable to exploit the full potential of process integration between the reaction operation and separation operation involved. In the separations of reacting mixtures with unfavorable thermodynamics (e.g., A + B ↔ C + D with αA > αC > αD > αB), the RDC-SRS may even lose competitiveness against its conventional counterpart and this limits overwhelmingly its applicability and effectiveness.

5

The arrangement of

multiple reactive sections (which, for example, gives rise to a reactive distillation column with double reactive sections (RDC-DRS) or a reactive distillation column with triple reactive sections (RDC-TRS)) can add great flexibilities to process synthesis and design and hence improve their steady-state performance and broaden their applicability. 6 With reference to the separations of unfavorable quaternary reacting mixtures (e.g., A + B ↔ C + D with αA > αC > αD > αB), Zhang et al. demonstrated that the RDC-DRS was much more energy efficient than the RDC-SRS. 7, 8 In terms of the separations of reacting mixtures involving two-stage consecutive reversible reactions (e.g., A + B ↔ C + D, C + B ↔ E + D with αD > αB > αC > αA > αE), Yu et al. confirmed again the great advantages of the RDC-DRS over the RDC-SRS. 6 In the case of separating the disproportionation of trichlorosilane to silane (i.e., a three-stage consecutive reversible reaction that will be studied in the current work), Zang et al. indicated that the incremental arrangement of reactive sections resulted in a steady improvement in steady-state performance from the RDC-SRS to the RDC-DRS and finally to the RDC-TRS. 9 Despite the great advantages of adopting multiple reactive sections in process synthesis and design, only a few researches have been directed so far to the dynamics and controllability of the RDC-DRS (not to mention the RDC-TRS). Kaymak et al. studied the temperature control of the RDC-DRS separating the two-stage consecutive reversible reactions (i.e., A + B ↔ C + D, C + B ↔ E + D with αD > αB > αC > αA > αE) and pointed out that without the direct measurements of top and bottom product compositions it would be impossible to achieve tight process operation.

10

Cao et al. examined the dynamics and control of the RDC-DRS separating

unfavorable quaternary reacting mixtures (e.g., A + B ↔ C + D with αA > αC > αD > αB) and evinced that feed splitting of the 3



lightest and heaviest reactants presented favorable influences to process dynamics and controllability.

Page 4 of 19

11

With regard to the

arrangement of multiple reactive sections, since it represents the most effective philosophy for enhancing the steady-state performance of a reactive distillation column, it is of great significance to ascertain further its impacts to process dynamics and controllability. A full and clear picture about this design philosophy is deemed to be quite essential to process design and operation. The major purpose of the current work is to gain insights into the dynamic behaviors of the RDC-SRS, RDC-DRS, and RDC-TRS processing the disproportionation of trichlorosilane to silane. Detailed open-loop and closed-loop analyses are conducted, with special concern on the impact of arranging multiple reactive sections on process dynamics and controllability.

2.

DESIGNS OF THE RDC-SRS, RDC-DRS, AND RDC-TRS DISPROPORTIONATING TRICHLOROSILANE TO

SILANE The disproportionation of trichlorosilane to silane is characterized by a three-stage consecutive reversible reaction with a rather unfavorable reaction kinetics of a near zero thermodynamic conversion (c.f. eqs. 1-8). 12-14 It involves five reacting components, including silicon tetrachloride (STC), trichlorosilane (TCS), dichlorosilane (DCS), monochlorosilane (MCS), and silane.

Figure 1 sketches the designs of the RDC-SRS, RDC-DRS, RDC-TRS given in our recent work,

9

and Table S1 in

Supporting Information details their nominal operating conditions. In spite of the fact that they accommodate the same total number of stages and the same total number of reactive stages (each reactive stage contains 60.25 mole of resin Amberlyst A-21), the arrangement of multiple reactive sections enhances greatly the steady-state performance by lowering, respectively, the heat duty of condenser from 406.09 kW (RDC-SRS) to 372.1 kW (RDC-DRS) and finally to 363.8 kW (RDC-TRS). Due to the adjustment of pressure drop from 0.0049 atm to 0.0068 atm per stage, the values become now slightly smaller than those reported in the corresponding paper. In the following sections, their dynamics and controllability are to be examined in terms of in-depth comparative analysis of their dynamic behaviors. 2TCS ↔ STC + DCS

∆Ηr = 6402 kJ/kmol

(1)

2DCS ↔ TCS + MCS

∆Ηr = 2226 kJ/kmol

(2)

2MCS ↔ DCS + silane

∆Ηr = −248 kJ/kmol

(3)

r1 = k1 (x2TCS − xSTCxDCS/K1)

(4) 4


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3.

r2 = k2 (x2DCS − xTCSxMCS/K2)

(5)

r3 = k3 (x2MCS − xDCSxsilane/K3)

(6)

ki = k0,i exp(−Ei /RT)

i = 1, 2, 3

(7)

Ki = K0,i exp(−∆Hi /RT)

i = 1, 2, 3

(8)

OPEN-LOOP CONTROLLABILITY EVALUATION FOR THE RDC-SRS, RDC-DRS, AND RDC-TRS In the first place, the regulation path is to be examined (i.e., from reflux flow rate and reboiler heat duty to the top and

bottom product compositions, respectively). Because temperature control generally involves steady-state offsets in the controlled product compositions and this can arouse uncertainties to the study of process controllability, direct composition control is employed in the current work.

15-16

Shown in Figure 2 are the open-loop transient responses of the RDC-SRS,

RDC-DRS, and RDC-TRS aroused by the step changes in nominal operating conditions. The black curves denote the positive responses and the gray curves the negative ones. With the reflux flow rate disturbed by ±1 % from their nominal steady-state values (c.f. Figure 2a), the three process designs can be said to share almost the same responses in the top product. In the bottom product, the RDC-SRS exhibits the greatest magnitude of variations, then followed by the RDC-DRS and finally by the RDC-TRS, implying increasingly alleviated interaction between the top and bottom control loops by the arrangement of multiple reactive sections in process synthesis and design. With the reboiler heat duty disturbed by ±1 % from their nominal steady-state values (c.f. Figure 2b), the three process designs can be said to share again almost the same responses in the top product (note also the fact that the differences of variation magnitudes in Fig. 2b left are considerably smaller than those in Fig. 2b right). In the bottom product, although their differences look rather small, the RDC-SRS still exhibits the greatest magnitude of variations, then followed by the RDC-DRS and finally by the RDC-TRS, implying slightly deteriorated controllability by the arrangement of multiple reactive sections in process synthesis and design. For the assessment of the net effect of these two conflicting changes in process dynamics and controllability, relative gain array (RGA) at the low frequency of 1×10-4 rad/h and the high frequency of 1×104 rad/h is calculated and listed in Table 1 (the high frequency is chosen here because beyond which no changes at all occur in the RGA). Note that the diagonal elements become slightly closer to one in the RDC-DRS and RDC-TRS than in the RDC-SRS. In spite of the fact that the variations are not so significant, they indicate definitely that the arrangement of multiple reactive sections presents essentially favorable net effects to process dynamics and controllability in 5



Page 6 of 19

the regulation path. In the second place, the disturbance path is to be examined (i.e., from feed flow rate and composition to the top and bottom product compositions, respectively). With the feed flow rate disturbed by ±5 % from its nominal steady-state value (c.f. Figure 2c), while the top product shows an increasingly intensified sensitivities from the RDC-SRS to the RDC-DRS and finally to the RDC-TRS, the bottom product displays a completely reversed order of sensitivities especially in the case of the positive variation in feed flow rate. With the feed composition disturbed by 5 % from its nominal steady-state value (c.f. Figure 2d), again, a completely reversed order of sensitivities occurs between the top and bottom products, namely, the top product shows an increasingly intensified sensitivities from the RDC-SRS to the RDC-DRS and finally to the RDC-TRS while the bottom product displays a completely reversed order of sensitivities. Although the suppression of the sensitivity of the top product gives rise to increasingly severe interactions to the bottom control loop (from the RDC-SRS to the RDC-DRS and finally to the RDC-TRS), the increasingly low sensitivity of the bottom product may allow the bottom control loop to attenuate the interactions without necessary changes in its influences the top control loop. Thus, it is reasonable to argue that the arrangement of multiple reactive sections is likely to present negligible influences to process dynamics and controllability in the disturbance path.

4.

CLOSED-LOOP CONTROLLABILITY EVALUATION FOR THE RDC-SRS, RDC-DRS, AND RDC-TRS In the light of the RGA analysis, multi-loop control schemes are designed and sketched in Figure 3 for the RDC-SRS,

RDC-DRS, and RDC-TRS, respectively. While the top product composition of silane is controlled with reflux flow rate, the bottom product composition of STC is controlled with reboiler heat duty. Table 2 lists the controller parameters acquired by the Tyreus-Luyben rule embedded in the commercial software Aspen Dynamics. Note that from the RDC-SRS to the RDC-DRS and finally to the RDC-TRS, while the proportional gain shows an increasing tendency the integral time shows a decreasing tendency in both the top and bottom control loops. The phenomenon implies an increasingly tight tuning of the multi-loop control systems and these are apparently allowed by the arrangement of double and triple reactive sections to the RDC-DRS and RDC-TRS. Figure 4 depicts the regulatory responses of the RDC-SRS, RDC-DRS, and RDC-TRS after they face a ±5 % step change in feed flow rate of TCS. The RDC-SRS shows slightly oscillatory responses with the greatest peak deviations and the longest settling times in both the top and bottom products. The RDC-DRS exhibits no oscillations at all with substantially 6


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suppressed peak deviations and settling times in both the top and bottom products. The RDC-TRS presents further suppressed peak deviations and settling times in both the top and bottom products. Depicted in Figure 5 are the regulatory responses of the RDC-SRS, RDC-DRS, and RDC-TRS after they are in face of a 5 % step change in feed composition (i.e., 5 % silane and 95 % TCS). Extremely similar to the circumstances of the feed flow rate disturbances, the RDC-SRS, RDC-DRS, and RDC-TRS display increasingly suppressed peak deviations and settling times in both the top and bottom products. Servo responses to the changes in the top and bottom product set-points are also examined and shown in Figures S1 and S2 of Supporting Information. Apart from the settling times of the top and bottom products, the RDC-SRS, RDC-DRS, and RDC-TRS display increasingly suppressed interactions between the top and bottom control loops.

5.

CONCLUSIONS With reference to the disproportionation of TCS to silane, the impact of arranging multiple reactive sections on process

dynamics and controllability has been examined in terms of comparative analysis of open-loop and closed-loop behaviors between the RDC-SRS, RDC-DRS, and RDC-TRS. The open-loop analysis is in excellent accordance with the closed-loop analysis and they both indicate that the arrangement of multiple reactive sections yields a favorable effect to process dynamics and controllability in addition to its great economic potential to process synthesis and design as demonstrated already in our recent work. These outcomes highlight the great effect and importance of taking the number of reactive sections as a structural decision variable in compromising process design and process operation. Although these findings have been deduced through the separation of the disproportionation of TCS to silane, they are still considered to be of general significance for the design and control of reactive distillation columns separating complicated reacting mixtures involving multiple reversible reactions.

SUPPORTING INFORMATION Nominal operating conditions and servo responses of the RDC-SRS, RDC-DRS, and RDC-TRS.

ACKNOWLEDGEMENTS Financial support from National Nature Science Foundation of China (21076015, 21376018, 21576014, and 21676011) is acknowledged. 7



Page 8 of 19

LITERATURE CITED (1)

Taylor, R.; Krishna, R. Modeling Reactive Distillation. Chem. Eng. Sci. 2000, 55, 5183-5229.

(2)

Malone, M. F.; Doherty, M. F. Reactive Distillation. Ind. Eng. Chem. Res. 2000, 39, 3953-3957.

(3)

Almeida-Rivera, C. P.; Swinkels, P. L. J.; Grievink, J. Designing Reactive Distillation Processes: Present and

Future. Comput. Chem. Eng. 2004, 28, 1997-2020. (4)

Luyben, W. L.; Yu, C. C. Reactive Distillation Design and Control; John Wiley & Sons, Inc.: Hoboken, NJ, 2008.

(5)

Tung, S. T.; Yu, C. C. Effects of Relative Volatility Ranking to the Design of Reactive Distillation. AIChE J. 2007,

53, 1278-1297. (6)

Yu, C.; Yao, X.; Huang, K.; Zhang, L.; Wang, S.; Chen, H. A Reactive Distillation Column with Double Reactive

Sections for the Separations of Two-Stage Consecutive Reversible Reactions. Chem. Eng. Proc. 2014, 79, 56-68. (7)

Zhang, L.; Chen, H.; Yuan, Y.; Yu, J.; Wang, S.; Huang, K. Synthesis and Design of Reactive Distillation Columns

with Two Reactive Sections. Chem. Eng. Res. Des. 2015, 100, 311-322. (8)

Zhang, L.; Chen, H.; Yuan, Y.; Wang, S.; Huang, K. Adopting Feed Splitting in Design of Reactive Distillation

Columns with Two Reactive Sections. Chem. Eng. Proc. 2015, 89, 9-18. (9)

Zang, X.; Huang, K.; Yuan, Y.; Chen, H.; Zhang, L.; Wang, S.; Wang, K. Reactive Distillation Columns with

Multiple Reactive Sections: A Case Study on the Disproportionation of Trichlorosilane to Silane. Ind. Eng. Chem. Res. 2017, 56, 717-727. (10) Kaymak, D. B.; Unlu, H.; Ofkeli, T. Control of a Reactive Distillation Column with Double Reactive Sections for Two-Stage Consecutive Reactions. Chem. Eng. Proc. 2017, 113, 86-93. (11) Cao, Y.; Huang, K.; Yuan, Y.; Chen, H.; Zhang, L.; Wang, S. Dynamics and Control of Reactive Distillation Columns with Double Reactive Sections: Feed-Splitting Influences. Ind. Eng. Chem. Res. 2017, 56, 8029-8040. (12) Huang, X.; Ding, W. J.; Yan, J. M.; Xiao, W. D. Reactive Distillation Column for Disproportionation of Trichlorosilane to Silane: Reducing Refrigeration Load with Intermediate Condensers. Ind. Eng. Chem. Res. 2013, 52, 6211-6220. (13) Alcántara-Avila, J. R.; Tanaka, M.; Márquez, C. R.; Gómez-Castro, F. I.; Segovia-Hernández, J. G.; Sotowa, K. 8


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I.; Horikawa, T. Design of a Multitask Reactive Distillation with Intermediate Heat Exchangers for the Production of Silane and Chlorosilane Derivates. Ind. Eng. Chem. Res. 2016, 55, 10968-10977. (14) Ramírez-Márquez, C.; Sánchez-Ramírez, E.; Quiroz-Ramírez, J. J.; Gómez-Castro, F. I.; Ramíre-Corona, N.; Cervantes-Jauregui, J. A.; Segovia-Hernández, J. G. Dynamic Behavior of a Multi-tasking Reactive Distillation Column for Production of Silane, Dichlorosilane and Monochlorosilane. Chem. Eng. Proc. 2016, 108, 125-138. (15) Huang, K.; Nakaiwa, M.; Tsutsumi, A. Towards Further Internal Heat Integration in Design of Reactive Distillation Columns—Part II. The Process Dynamics and Operation. Chem. Eng. Sci. 2006, 61, 5377-5392. (16) Cantrell, J. G.; Elliott, T. R.; Luyben, W. L. Effect of Feed Characteristics on the Controllability of Binary Distillation Columns. Ind. Eng. Chem. Res. 1995, 34, 3027-3036.

9



Page 10 of 19

Figure Captions Figure 1.

Process designs for the disproportionation of trichlorosilane to silane: (a) RDC-SRS; (b) RDC-DRS; (c) RDC-TRS.

Figure 2.

Open-loop responses of the RDC-SRS, RDC-DRS, and RDC-TRS: (a) ±1 % step change in reflux flow rate; (b) ±1 % step change in reboiler heat duty; (c) ±5 % step change in feed flow rate; (d) 5 % step change in feed composition (i.e., 5% silane and 95 % TCS).

Figure 3.

Control schemes of the three process designs: (a) RDC-SRS; (b) RDC-DRS; (c) RDC-TRS.

Figure 4.

Regulatory responses of the RDC-SRS, RDC-DRS, and RDC-TRS to a ±5 % step change in feed flow rate: (a) silane in top product; (b) reflux flow rate; (c) STC in bottom product; (d) reboiler heat duty.

Figure 5.

Regulatory responses of the RDC-SRS, RDC-DRS, and RDC-TRS to a 5% step change in feed composition (i.e., 5% silane and 95 % TCS): (a) silane in top product; (b) reflux flow rate; (c) STC in bottom product; (d) reboiler heat duty.

10


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QCOND = 406.1 kW

2 14

QCOND = 372.1 kW

T: 194.9 K silane: 99.3 % 2.487 kmol/h R = 121.9 kmol/h

T: 194.9 K silane: 99.3 % 2.487 kmol/h

2 5

R = 111.4 kmol/h

11 22

23 FTCS = 10 kmol/h

NR, 1 = 31

24

NR, 1 = 7 NR, 2 = 24

FTCS = 10 kmol/h

44 45

59

QREB = 447.5 kW

59

QREB = 413.5 kW

T: 393.5 K STC: 99.1 % 7.513 kmol/h

T: 393.5 K STC: 99.1 % 7.513 kmol/h

(a)

(b)

QCOND = 363.8 kW

T: 194.9 K silane: 99.3 % 2.487 kmol/h

2 5 R = 108.9 kmol/h 9 13

NR, 1 = 1

22

NR, 2 = 5

24

NR, 3 = 25

FTCS = 10 kmol/h 46

QREB = 405.2 kW

59

T: 393.5 K STC: 99.1 % 7.513 kmol/h (c)

Figure 1 Kejin Huang, Yang Yuan, Xinxiang Zang, Haisheng Chen, Liang Zhang, Xing Qian, and Shaofeng Wang Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane

11



0.9925

0.9956

STC (mole fraction)

silane (mole fraction)

0.9984

RDC-SRS RDC-DRS RDC-TRS

0.9928

0.99

0.99165

0.9908

RDC-SRS

RDC-DRS

RDC-TRS

0.98995

0.9891

0.9872 0

2

4 Time (h)

6

0

8

2

4 Time (h)

6

8

(a) 0.997

0.9957

STC (mole fraction)


0.9987


0.9927

0.9897

0.99325 RDC-SRS RDC-DRS RDC-TRS

0.9895

0.98575

0.982

0.9867 0

2

4 Time (h)

6

0

8

2

4 Time (h)

6

8

(b) 1.003

0.99345

STC (mole fraction)


0.9947


0.9922

0.99095

0.9897


0.968

0.9505

0.933 0

2

4 Time (h)

6

8

0

2

4 Time (h)

6

8

(c) 0.99345

0.9995 0.9977

0.9932

STC (mole fraction)


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 19


0.99295

0.9927


0.9941 0.9923

0.99245

0.9905

0

2

4 Time (h)

6

8

0

2

4 Time (h)

6

8

(d)


12


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PC

PC

LC1

LC1

2

2

silane

silane

5

14 F

CC1

CC1

11 22 24

F

23 FC

FC

44

45 45

59

59

LC2

LC2

CC2

CC2

STC

STC

(a)

(b)

PC LC1

2 5 9 13 22 24

F

silane CC1

45 46

FC

59

LC2

CC2

STC (c)


13




0.996

0.994


0.99 0

2

4

6 Time (h)

8

10

(a)

(b)

0.999

1.75

RDC-SRS

0.9945

QREB (GJ/h)

STC (mole fraction)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 19

0.99

RDC-DRS

RDC-TRS

1.61


0.9855

0.981 0

2

4

6

8

10

1.33 0

2

Time (h)

4

6

8

10

Time (h)

(c)

(d)


14


Page 15 of 19



0.99495

0.9942

0.99345

0.9927 0

2

4

6

8

10

Time (h)

(a)

(b) 1.625


0.9963


1.555

QREB (GJ/h)

STC (mole fraction)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


0.9946

0.9929

1.485

1.415

0.9912

1.345

0.9895 0

2

4

6

8

10

0

2

4

6

8

10

Time (h)

Time (h)

(b)

(d)


15



Page 16 of 19

Table Captions -4

4

Table 1.

RGA for the RDC-SRS, RDC-DRS, and RDC-TRS at 1×10 and 1×10 rad/h

Table 2.

Controller parameters of the RDC-SRS, RDC-DRS, and RDC-TRS

16


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-4

4

Table 1. RGA for the RDC-SRS, RDC-DRS, and RDC-TRS at 1×10 and 1×10 rad/h

ω = 1×10-4 rad/h

ω = 1×104 rad/h

Xsilane

XSTC

Xsilane

XSTC

R

1.0945

−0.0945

1.0515

−0.0515

QREB

−0.0945

1.0945

−0.0515

1.0515

R

1.0856

−0.0856

1.0478

−0.0478

QREB

−0.0856

1.0856

−0.0478

1.0478

R

1.0923

−0.0923

1.0479

0.0479

QREB

−0.0923

1.0923

−0.0479

1.0479

Process design

RDC-SRS

RDC-DRS

RDC-TRS

Kejin Huang, Yang Yuan, Xinxiang Zang, Haisheng Chen, Liang Zhang, Xing Qian, and Shaofeng Wang Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane

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Page 18 of 19

Table 2. Controller parameters of the RDC-SRS, RDC-DRS, and RDC-TRS Process design RDC-SRS

RDC-DRS

RDC-TRS

Control loop

Manipulated variable

CC1

R

CC2

Controlled variable

KC (-)

TI (min)

Xsilane

6.06

29.04

QREB

XSTC

2.88

48.84

CC1

R

Xsilane

7.79

25.08

CC2

QREB

XSTC

3.74

46.20

CC1

R

Xsilane

8.31

23.76

CC2

QREB

XSTC

4.14

44.88

Kejin Huang, Yang Yuan, Xinxiang Zang, Haisheng Chen, Liang Zhang, Xing Qian, and Shaofeng Wang Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane

18


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TOC

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Controllability Evaluation for Reactive Distillation Columns with

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