Applications of Reaction Calorimetry in the Chemical Process Industry Reinaldo M. Machado 20 May 2105

Transcription

1 rm 2 technologies LLC Applications of Reaction Calorimetry in the Chemical Process Industry Reinaldo M. Machado 20 May 2105

2 fundamentals of scale-up Numerous physical and chemical processes interact during a manufacturing or synthesis process. New manufacturing processes require fundamental information for scale-up and safety analysis Kinetics Physical property changes Heat transfer Mixing Thermodynamics; Equilibrium Mass transfer ppt00 2

3 fundamentals of scale-up Heat is Evolved or Consumed by Most Chemical Reaction Processes Chemical reactions Phase changes Crystallization Vaporization/Condensation Sensible changes Mixing, solution Viscous dissipation Friction of fluid elements rubbing together ppt00 3

4 Heat Flow/Volume, watts/liter fundamentals of scale-up Heat Generation and Heat Removal Form the Basis of Reactor Scale-up and Safety Analysis ppt Heat Generation : q gen /V rctr = A * e {-Ea/RT} f(c A,C B ) Heat Removal : q cool /V rctr = (UA/V rctr ){T rctr -T jacket } Increasing UA/V rctr & Lowering T jacket Temperature, C

5 fundamentals of scale-up Traditional Heat Flow Calorimetry Using The Mettler RC1 Tj Tr Temperature Controller Q CAL Q FLOW Reactor temp., (Tr) is controlled by adjustment of jacket temp. (Tj) Jacket flow is sufficiently high that Tj is virtually constant, ±0.1 O C Q FLOW = U A ( Tr - Tj ) Calibration U A = Q CAL dt (Tr - Tj)dt ppt00 5

6 Tr-Tj, o C Tr, o C fundamentals of scale-up Profiles for a Simple Batch Co-Polymerization Time, minutes ppt00 6

7 Heat Production, watts Tr, o C fundamentals of scale-up Reaction Exotherm Profile for a Polymerization Process ppt Time, minutes

8 rm 2 technologies LLC Heat Transfer Characterization

9 fundamentals of scale-up Heat Transfer in CSTR s Can be Correlated According to Empirical and Fundamental Models 1/ 3 2/ 3 Nu Pr Re C wall 014. ppt00 9 Nu ht k Cp Pr k Re ND U * U h

10 Log [Nu/(Pr 0.33 )] fundamentals of scale-up Nu C Pr 1 3 Re 2 3 fluid wall Heat transfer characteristics of RC1 MP10 is similar to large scale reactors Pr Re Nu ppt00 10 ρ h fluid fluid μ k fluid Cp fluid ND fluid T fluid fluid Prandtl Number ReynoldsNumber Tank Diameter k 2 Nusselt Number Log (Re) Slope = 0.69

11 fundamentals of scale-up Heat Transfer Characterized By a Single Correlation Equation for a Stirred Tank Reactor / * N rctr o U U C V Z N wall 2 rctr k 2 rctr Cp rctr g rctr Material Heat Transfer Parameter 1 3 D 4 N o 2 g T 3 1/ 3 Reactor Geometric Parameter ppt00 11

12 1/U fundamentals of scale-up Wilson Plot Reveals Heat Transfer Resistances Intercept = 1/U* Slope = 1/(C V Z) Resistance of Reactor Wall and Jacket Fluid Resistance of Reactor Fluid (N o /N) 2/3 ppt00 12

13 fundamentals of scale-up Wilson Plot For Glycerol Reveals Impact of Temp. on Heat Transfer Coefficient U W/(m K) liter Lab Reactor 25 o C 40 o C 55 o C 0.5 U* = 120 W/(m 2 K) Nrpm 3 ppt00 13

14 fundamentals of scale-up Material Heat Transfer Parameter for Various Fluids at 30 o C Material V, W/(m 2 K) Water 27,100 Toluene 7,710 Sulfuric Acid 8,820 Isopropanol 5,960 Glycerol 1,690 Polymers 100 to ~10,000 cp 5,000 to ~500 ppt00 14

15 fundamentals of scale-up Deviations From Wilson Plot Indicate Mixing Problems Stagnant Zone Mixed Zone 1/U ppt00 15 Poor mixing High Wall Viscosity Pseudoplastic Fluid 1/U* Decreasing N(rpm) (N/N o ) -2/3

16 fundamentals of scale-up Heat transfer with anchor impeller at 100 rpm with glycerol in MP10 lab reactor (1.5 liter, heat load = 25 kw/m 3 ) V hr U Tr o C cp W/(m 2 K) r mm Tj o C Trw o C cp w ) U* = 120 W/(m 2 K) Measured values ppt00 16

17 fundamentals of scale-up Comparisons of VisiMix predictions and Experiments for Heat Transfer with Anchor Impeller at 100 rpm with Glycerol in the Mettler Toledo RC1 MP10 glass lab reactor Inlet Jacket Temp. o C Reactor Temp. o C Reactor fluid, cp Re Overall Heat transfer coeff. U W/(m 2 K) Heat removal rate, W Experiment VisiMix Experiment VisiMix Experiment VisiMix ppt00 17

18 fundamentals of scale-up Review article for coils in Agitated Vessels ppt00 18

19 fundamentals of scale-up Tranter Prime Surface Heat Exchangers can serve as both baffles and heat exchangers Photos from Tranter Inc. product brochure Plate coils are fabricated by embossing channels on opposing plates and welding plates together. Uniform temperature distribution. ppt00 19

20 rm 2 technologies LLC Reaction Rate Analysis: Hydrogenation

21 fundamentals of scale-up Examples from a Hydrogenation/Oxidation process development laboratory ppt00 21

22 Normalized Rates, 1/hr RPM fundamentals of scale-up Process Rates for Reductive Alkylation Help Identify Interaction of Feed Rate and Mixing R-NH H 2 C=O + 2 H 2 R-N(CH 3 ) H 2 O + Q heat Formaldehyde Hydrogen Heat ppt Time, hrs.

23 fundamentals of scale-up No baffle Baffle ppt00 23

24 V liquid (cm 3 )*k L a(s -1 ) fundamentals of scale-up RC1 MP10 hydrogen mass transfer correlation in MeOH and IPOH Methanol/H 2 V*k L a = *N R 2 = ppt Isopropanol/H 2 V*k L a = *N R 2 = rpm

25 fundamentals of scale-up Lets take a look at developing a semi-batch process chemistry for Nitrobenzene hydrogenation to Aniline : The Engineer s View! NO 2 + 3H 2 NH 2 + 2H 2 O H reaction = -537 kj / mole ppt00 25

26 fundamentals of scale-up Semi-batch operation can be used to simulate features of continuous operation under specific conditions Continuous Semi-batch dn dt = Q in C in - Q out C out - Rate V R at high conversion dn = Qin C in - Rate V R dt dn dt = Q in C in - Rate V(t) with small volume changes ppt00 26

27 Reaction Rate, watts fundamentals of scale-up Feed rate affects reaction rate during multi-ramp feed experiments. Lessons: 1) Calorimetry is a convenient method for measuring the overall reaction rates, 2) Programing feeds allow rapid kinetic characterization Theoretical Feed Controlled Rate (~Infinitely Fast Reaction) = Q = Feed rate x DH reaction Reaction Rate ppt Time, minutes

28 fundamentals of scale-up Recall that the reduction of nitrobenzene can take two paths! Maybe changing conditions change between the paths. Nitrobenzene Nitrosobenzene Phenylhydroxylamine Aniline NO 2 H 2 NO H 2 H 2 NOH NH 2 H ppt N N O - H 2 N N H 2 N N H H Phenylhydrazine Azoxybenzene Azobenzene H 2 2 NH 2 Aniline

29 Reaction Rate, watts Wt% Intermediates fundamentals of scale-up When the feed rate was too fast for conditions (catalyst type, catalyst amount, pressure) nitrobenzene and intermediates accumulated to poison catalyst. Lesson: Engineers really do need Chemists! Nitrobenzene Azoxybenzene Azobenzene ppt Time, minutes

30 Reaction Rate, watts Mass of Feed Added, grams fundamentals of scale-up Pressure increases the maximum rate which can be achieved. Identical programed multi-ramp feed experiments used to characterize process capability. Lesson: Use programed recipes to test conditions, catalysts, raw material quality Total Reactor Pressure 11 barg 8 barg Feed Addition 50% Aniline/ 50% Nitrobenzene ppt Time, minutes

31 Reaction Exotherm, Watts fundamentals of scale-up Programmed Disturbance Patterns Can Be Used to Screen Catalyst Performance Three Increasing Feed Ramps; Repeated 1a 2a 3a 1b 2b 3b Reaction Time, hrs ppt00 31

32 fundamentals of scale-up ppt00 32

33 fundamentals of scale-up Biazzi Impeller and mixing system ppt00 33

34 rm 2 technologies LLC Reaction Rate Analysis : Soybean oil hydrogenation

35 fundamentals of scale-up Mass transfer tells us how fast we absorb H 2 H 2 (gas) H 2 (liquid) Rate of Absorption = k L a (sec -1 ) { [H 2 ]sat.- [H 2 ]bulk } Rate Constant Driving Force Increases with Agitation Intensity and H 2 Flow Increases with Pressure and Usually Increases with Temperature ppt00 35

36 fundamentals of scale-up Hydrogenation of Soybean Oil H H C O O H H H H H H H H H H H H H H C C C C C C C C C C C C C C C C C C C H O H H H H H H H H H H H H H H H H H H H C O H C O H C R O GLYCEROL C R FATTY ACID Approximately 50% of double bonds are Polyunsaturates ppt00 36

37 fundamentals of scale-up Olefin Hydrogenation Reactions R R' + H 2 Catalyst R R' + ~23 kcal/mole H 2 R cis R' H 2 Catalyst + R R' + ~23 kcal/mole H 2 trans R R' Catalyst H 2 R R' cis trans ppt00 37

38 Rate, watts/kg fundamentals of scale-up Process Conditions Impact Soybean Oil Hydrogenation Rates: Calsicat E-479D psig, 180 o C, kla=0.013 /sec 30 psig, 180 o C, kla=0.2 /sec 45 psig, 180 o C, kla=0.013 /sec 30 psig, 200 o C, kla=0.013 /sec ppt Reaction Time, minutes

39 Rate, watts/kg fundamentals of scale-up Various Process Conditions Reveal a Consistent ~50% Conversion psig, 180 C, kla=0.2/sec 30 psig, 180 C, kla=0.013/sec Polyunsaturate psig, 180 C, kla=0.013/sec % Conversion 30 psig, 200 C, kla=0.013/sec Monosaturate ppt00 39

40 Rate, watts/kg fundamentals of scale-up Catalysts can be Screened for Selectivity and Activity Selective Catalyst w/ High Activity Non Selective Catalyst % Conversion ppt00 40

41 fundamentals of scale-up Key Spectral Features of Soybean Oil 100% Hydrogenated 50% Hydrogenated 965 cm -1 trans-isomer 3011 cm -1 cis-isomer Virgin Oil 1749 cm -1 ester Wavenumber, cm -1 ppt00 41

42 Absorbance fundamentals of scale-up FTIR Profiles Track trans - Formation Time, min. Wavenumber cm -1 ppt00 42

43 Absorbance fundamentals of scale-up FTIR Profiles Track cis- Disappearance 0.90 ppt Wavenumber cm Time, min.

44 Fraction fundamentals of scale-up cis -trans -isomer Fraction during Soybean Oil Hydrogenation : Calsicat E-428D psig, 180 o C kla = sec -1 (1000 rpm) cis-isomer trans-isomer % Conversion ppt00 44

45 % Trans in Unreacted Double Bonds fundamentals of scale-up trans- Formation for Selective Calsicat E-428D is Not Sensitive to Process Variables 30 psig, 180 C, kla=0.013 /sec 30 psig, 180 C, kla=0.2 /sec 45 psig, 180 C, kla=0.013 /sec 30 psig, 200 C, kla=0.013 /sec 7 psig, 160 C to 215 C, Breen [1] ppt % Conversion 0 60

46 rm 2 technologies LLC Reaction Rate Analysis : Propoxylation of an aromatic amine

47 fundamentals of scale-up MDA Propylene Oxide Reactions to Mono-, Di-, Tri- and Quad- Substituted Products 1. 1 H 2 N N H 2 H 2 N A PO O M N H O H O 2 N H 2 M N H O H N H D12 O H N H O H O 4. 4 O H N H D12 N H O H H O N H T H O N C H 2 O H ppt00 47

48 fundamentals of scale-up Symmetry and Similarity Suggest Kinetic Models with 2 Independent Rate Constants Rate 1 = k 1 C A C PO Rate 2 = k 2 C M C PO k 2 = k 1 /2 Rate 3 = k 3 C M C PO Rate 4 = k 4 C D12 C PO Rate 5 = k 5 C D11 C PO Rate 6 = k 6 C T C PO k 4 = 2 k 3 k 5 = k 1 /2 k 6 = k 3 k 1 = A 1 exp{-e 1 /RT} ppt00 48 k 3 = A 3 exp{-e 3 /RT}

49 Reaction Rate, watts PO Added, gmoles fundamentals of scale-up Typical Rate Profile at 85 o C Propylene Oxide Reaction Rate Time, hr 0 ppt00 49

50 Reaction Rate, Qr, watts fundamentals of scale-up Comparison of Actual and Simulated Rate Profiles 100 o C Lines = Simulation Points = Data 85 o C 70 o C ppt Time, hrs

51 fundamentals of scale-up Final Rate Parameters Show Primary Amines ~10 x s Faster than Secondary Amines k 1 = k 1 (T o )exp{e 1 /RT o (1-T o /T)} k 3 = k 3 (T o )exp{e 3 /RT o (1-T o /T)} k 1 = 6.29 x10-6 m 3 /(mol s) exp{48.2 kj/mol /RT o (1-T o /T)} k 3 = 6.45 x10-7 m 3 /(mol s) exp{48.5 kj/mol /RT o (1-T o /T)} T o = 85 o C ppt00 51

52 Component mass (predicted), kg fundamentals of scale-up Comparison of Predicted and Observed Component Mass at all Temperatures Mono Tri Di Quad 0.20 Parity 0.10 ppt Component mass (observed), kg

53 Mole Fraction Amine Groups fundamentals of scale-up Impact of PO Stoichiometry on Selectivity at 85 o C Primary Secondary Tertiary ppt Moles Propylene Oxide/Mole MDA

54 rm 2 technologies LLC Reaction Rate Analysis: Oxidation of an alcohol

55 fundamentals of scale-up Discrimination of Kinetic Models Composition analysis alone is an incomplete method of determining accurate kinetic models Analysis of continuous rate measurement in combination with composition is the best way to discriminate various kinetic models ppt00 55

56 Concentration of A, gmole/m 3 Reaction Rate, gmole/(m 3 min) fundamentals of scale-up ppt00 56 Model Discrimination: C A0 =100 gmole/m 3, C B0 =80 gmole/m 3 A+B C order 1st-order 2nd-order 0-order 1st-order 2nd-order Lines = Rate Points = Concentration Time, minutes

57 fundamentals of scale-up Case History: Alcohol Oxidation with Heterogeneous Catalysis R OH Cat. + O 2 + M + OH - R O CO - M H 2 O Original research determined that this reaction was 1 st order in the alcohol. The batch kinetics O data was based exclusively OH on composition samples, approximately 10 samples per experiment. CO - M + Oxygen + 2 H 2 pressure was held constant. R + M + OH - R ppt00 57

58 Rate, watts Pressure, barg fundamentals of scale-up Batch Alcohol Oxidation to Carboxylate Salt 250 R OH + O 2 + M + OH - R O CO - M H 2 O Rate Pressure Time, minutes 0 ppt00 58

59 Rate, mole/[sec m 3 ] Pressure, barg fundamentals of scale-up Typical Reaction Characterization of Alcohol Oxidation with a Slurry Catalyst indicates more complex Kinetics st order region O st order region Rate Pressure % 10% 20% 30% 40% 50% Substrate Concentration (based on thermal conversion) ppt00 59

60 fundamentals of scale-up Rate Typical Heterogeneous Kinetics: Oxidation of Substrate S k Rate 1 With high wt% C k 1 K Rate O M asstransfer, C 2 k, sat. wt% C C S where, wt% wt% C 1 S Zero - order in S, 1st - S C O 2 K, sat. C 0, S 1st C Weight% catalyst S O 2 - O 2 C O 2, sat. order in O order in S & O Simple model explains results! 2 2 ppt00 60

61 rm 2 technologies LLC Thermal Safety Analysis: Propoxylation of an aliphatic amine

62 fundamentals of scale-up Illustration Problem: Propylene Oxide Addition to an Amine; A(amine) + B(propylene oxide) C Homogeneous Liquid Phase The amine is in large excess over propylene oxide Reaction is 1 st -order in propylene oxide Reactor volume can be assumed constant Propylene oxide is added at a constant rate over time, t add O R 1 NH 2 + R 1 N H OH ppt00 62

63 Heat Evolution, watts Mass of PO, grams fundamentals of scale-up Heat Evolution is a Function of Reactor Temperature and Feed Rate, 60 o C 20 PO + Amine Alcohol ppt Time, minutes

64 normalized reaction rate(w)/total heat (J), (s -1 ) x 1000/60 Temp. fundamentals of scale-up Accumulated propylene oxide can be considered Stored Energy during semi-batch addition 2.5 End of addition This is what could happen if we loose cooling at the end of the addition! Time Stored reaction end of PO addition time, minutes ppt00 64

65 normalized reaction rate(w)/total heat (J), (s -1 ) x 1000/60 fundamentals of scale-up Increasing addition time reduces maximum exotherm and stored reaction energy min. addition time for propylene oxide 480 min. addition time for propylene oxide time, minutes ppt00 65

66 normalized reaction rate(w)/total heat (J), (s -1 ) x 1000/60 fundamentals of scale-up Increasing reactor temperature reduces stored reaction energy o C 75 o C o C time, minutes ppt00 66

67 Final Reactor Temp., o C fundamentals of scale-up MTSR After Cooling Loss Just at the Point of Complete Propylene Oxide Addition (120 minutes) o C Limiting Temp. 110 o C o C Net Adiabatic DT = 100 o C Reactor Temp., o C, During Addition of PO ppt00 67

68 Final Reactor Temp., o C fundamentals of scale-up MTSR After Cooling Loss Just at the Point of Complete Propylene Oxide Addition min. 30 min min. Addition Rate Reactor Temp., o C, During Addition of PO ppt00 68

69 rm 2 technologies LLC General Conclusions

70 fundamentals of scale-up Reaction Calorimetry Realtime rate feedback allows investigators to interact and optimize processes online Addition Strategy and Feed Rates are key process design variables Thermal Reaction Profiles generated to compare process strategies screen raw materials with programmed Disturbance patterns; temperature, feed rate, pressure. agitation process thermal spectra ppt00 70 Heat transfer characterization of difficult materials and intermediates

71 fundamentals of scale-up Reaction Calorimetry Characterizes Kinetics, Mass Transfer, Heat Transfer, Thermodynamics, Physical Property Changes Thermal Data Allows Efficient Development of Optimized processes Scaleable process Safe processes ppt00 71

72 fundamentals of scale-up Online FTIR Monitors Selectivity in Complex Reaction Sequences ConcIRT Provides Rapid Analysis without Standards ppt00 72

73 fundamentals of scale-up Semibatch Processes at High Temperature Can be Advantageous Lower reaction mass viscosity Improved mixing Improved heat transfer Higher heat removal driving force, Tr-Tj Increased kinetic reaction rates Shorter batch times Improved reagent and product solubility Reduced risk of reagent accumulation Lower stored exotherm energy ppt00 73

74 fundamentals of scale-up Semibatch Processes at High Temperature may also create unwanted results Increase rate of by-product formation Lower selectivity due to by-product formation Color problems Increase pressure from increased solvent vapor pressure Longer cool down time ppt00 74

75 fundamentals of scale-up Reinaldo Ray Machado phone: (484) Website: ppt00 75 Ray is the instructor of short course Fundamentals of Scale-up, which may be offered at your site. Reinaldo (Ray) Machado is the developer and instructor of a popular industrial short course, Fundamentals of Scale-up which he teaches part time. Proceeds from the course supports EWB, Engineers Without Borders. Ray is also currently employed by Air Products and Chemicals, Inc. in Allentown, PA where he serves as a senior process engineer supporting both the Electronics and Performance Materials Divisions. He also serves as a senior consultant specializing in gas/liquid reaction engineering and electrochemical engineering and provides global support for hydrogenation and oxidation applications for both internal and external customers. Ray has broad technical experience in applied reactor engineering, scale-up of chemical reaction processes, mass transfer, heat transfer, applied reaction calorimetry, hydrogenation, electrochemical engineering, sulfonation, amination, propoxylation, polymerization, and plastics recycling. Ray received a Ph.D. in chemical engineering with a concentration in chemistry from the University of Wisconsin, Madison, and a B.A. in chemistry and mathematics from Frostburg State University. He has served as a part-time instructor of a short course, Scale-Up Considerations in Chemical Processes, at Lehigh University and currently teaches industrial courses on the fundamentals of scale-up. He holds 17 patents, has collaborated on 17 publications, and is a member of the American Institute of Chemical Engineers and the American Chemical Society.

76 fundamentals of scale-up Titration by Reinaldo Machado Into the acid brew, fall bitter drops of base. Whirling pink ribbons, consumed without a trace. Each fresh drop gives life, to stronger crimson swirls. A spinning fatal dance, in twisting eddy whirls. A hesitant drop descends, into the vortex roll. A fiery flash of red transforms the mixture whole Reinaldo Machado ppt00 76 (c) Reinaldo Machado; rm2technologies LLC 2011