Micro Process Technology and bulk chemical industry - focussing on lessons learnt

Transcription

1 and bulk chemical industry - focussing on lessons learnt PoaC Symposium The Dutch process on a chip and micro reactor meeting May 22, 2013 Conference Center The Strip, Eindhoven, Netherlands Dr. Ralf Böhling Chemical Engineering, BASF SE

2 Outline 1 Micro Process BASF history and motivation 2 Lessons learnt Deydrogenation, Mercaptoethanol, Cyclohexane Oxidation 3 Applications and outlook Heat exchanger, Reactor, Evaporator, Mixer

3 Motivation Some Advantages commonly attributed to micro reactors... Inherently safe enables operation in the explosive regime No hot spot improved selectivity Numbering up instead of scale up easy transfer to production scale Fast mixing for improving selectivity. Source: Presentation of F. Lippert, Process BASF, Sep 7-10, 2008, Kyoto/Japan

4 History of Micro Process Technology World and BASF Publications Patents 1. IMRET in Frankfurt Chairman Dr. Jäckel BASF Implementation of a Heatric PCHE as compact heat exchanger Start of Operation of a Heatric PCHE as reactor for fine chemicals Dr. Wörz (BASF) starts cooperation with IMM (Prof. Ehrfeld) and FZK (Prof. Schubert) Fast liquid phase reactions, Oxy-dehydrogenation Start of SOLEMIO a BMBF founded project Focus on wall coated micro reactors Source: Presentation of F. Lippert, Process BASF, Sep 7-10, 2008, Kyoto/Japan BMBF-Project µ.pro.chem BASF, Degussa, IMM, BAM, TU-Chemnitz Bringing µ-reactors into technical scale EU-Projekt F³-Factory BASF, Bayer, Evonik, KIT, Astra Zeneca. Development of modular continuous plant

5 Outline 1 BASF history and motivation 2 Lessons learnt and bad luck Deydrogenation, Mercaptoethanol, Cyclohexane Oxidation 3 Applications and outlook Heat exchanger, Reactor, Evaporator

6 Dehydrogenation (heterogeneous gas phase) Strong exothermic heterogeneous gas phase reaction: Q: heat flow P: mass flow Q P Laboratory reactor S = 90% d: 50 mm former plant reactor S = 45 % d > 1m T = 550 C Laboratory microreactor S = 96% T: 390 C current plant reactor S = 80-85% d: 3m Tmax = 450 C Hot spot: 60 C Quelle: O.Wörz et al., Microreactors a new efficient tool for reactor development, Cem. Eng. Technol 24, 2 (2001)

7 Dehydrogenation Cooling channels 500 h 10 Vol.-% O C Pilot plant operation Silver micro reactor become leaky Structural failure Source: IMVT of KIT Catalytically active material is not suitable as construction material Source: Presentation of F. Lippert, Process BASF, Sep 7-10, 2008, Kyoto/Japan

8 Cyclohexane Oxidation (gas liquid phase) BMBF Förderkennzeichen 16SV O 2 OOH OH O + H 2 O Large scale industrial processes: T < 180 C / p < 20 bar / = min Cyclohexane conversion only < 6 % Selectivity: % Expectations in using a microreactor high mass and heat transfer increasing selectivity and/or conversion lowering reaction volume Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

9 Cyclohexane Oxidation Results of µ-experiments Uncatalyzed cyclohexane oxidation in capillary tubes D = mm / p = bar / conversion of cyclohexane 5 % Space-time-yield of up to 10 t/m 3 h achieved, impact of wall eliminated but: Selectivity decreases at higher temperatures project terminated Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

10 Mercaptoethanol (MCE) from EO and H 2 S BMBF Förderkennzeichen 16SV1992 Existing BASF Process Long residence time (>> 1 h) Low temperature and low pressure Byproduct TDG (up to 20 %), TDG is essential as catalyst highly exothermic gas-liquid reaction Potential for micro reactor? Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

11 Mercaptoethanol (MCE) from EO and H 2 S Lab results Lab results with several µ-reactors (T = C / p = bar / = 2 min) - Capillary tubes (d<1 mm) - Parallel channel structure (IMM) - Mingatec reactor STY up to 16 t/m 3 h achieved high selectivity only in liquid phase Selectivity up to 95 % achieved Pilot plant tests planned Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

12 Mercaptoethanol (MCE) from EO and H 2 S Flow chart pilot plant at EVONIK site Hanau-Wolfgang EO; H 2 S; N 2 MCE H 2 S EO Mixer (CSTR) 25 C Mixing zone Mingatec only µ-reactor 1. Sambay 1 bar 2. Sambay vacuum N 2 recycle TDG TDG TDG Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

13 Mercaptoethanol (MCE) from EO and H 2 S Pilot plant (start up III/07 at Evonik site Hanau-Wolfgang) Front view (work-up section on back side) IMM reactor Exchangeable microstructured reaction module Mingatec reactor Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

14 Mercaptoethanol (MCE) from EO and H 2 S µ-reactors tested in pilot plant IMM type Lab reactor 3 ml reactor volume Enlarged view: cut through the (BASF) reactor stack Heatric-type 130 ml pilot reactor (4 channels / 1.0 mm) Pilot reactor 90 ml (30 fold stack) Major step during manufacturing: brazing of the wet chemically etched plates Mingatec-reactor (Miprova, 2 types) 20 ml lab. reactor (1 channel / 1,7 x 12 mm / 3 x 0,5 mm N comb layers) 100 ml pilot reactor (12 channels / 1,2 x 12 mm / 2 x 0,5 mm N comb layers) Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

15 Sel. % Micro Process Technology Mercaptoethanol (MCE) from EO and H 2 S Pilot plant results MCE-Pilotanlage 110 C / 80 bar( 1,3 mol/mol H2S/EO) During start-up period: STY of up to 16 t/m 3 h confirmed Sel % at EO conversion of > 95 % achieved Conversion % Mingatec Labor Mingatec 100 ml Heatric II IMM Mingatec (+TDG) Kinetic 1 mm Rohr Kinetic 1 mm lab tube Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

16 Mercaptoethanol (MCE) from EO and H 2 S Results recycle TDG **A-Reactor * fresh TDG **B-Reactor With closed TDG-recycle: Fast plugging of all micro reactors Decrease in reactor performance * fresh TDG from the Lu-site BASF plant synthesis by addition of MCE and EO ** A and B-Reactor are two identical Heatric PCHE Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

17 Mercaptoethanol (MCE) from EO and H 2 S Results Heatric A-Reactor running with recycle TDG IMM Reactor running with recycle TDG Heatric B-Reactor running with fresh TDG scrubbing solutions after operation Instable process due to oligomer formation Continuous process only with additional TDG-work-up feasible Source: Presentation of R. Böhling, µ.pro.chem, ACHEMA Kongress 2009, May, Frankfurt am Main

18 Alkane Nitration (hom. gas phase) State of the art: DOW process with an adiabatic multi stage reactor with HNO 3 feeding between the stages operation up to 400 C broad product spectrum with nitromethane, nitroethane, 1- and 2- nitropropane... Low conversion with the need of propane recycle 2-nitropropane selectivity around % Target: > 50% propane selectivity, nearly full conversion to avoid the propane recycle Idea: Using a micro reactor to ensure isothermal conditions for shifting product mix to the kinetically preferred 2-nitropropan

19 Gas-Phase Alkane Nitration Background Challenge: Optimum reaction condition are in an explosive regime and elevated pressure range. Quenching distance for stochiom. Dependency of quenching distance and pressure combustible air mixture Gas - componente Hydrogen Quench distance [mm] 0,58 Methane 2,03 Ethylenoxide 1,17 Acetylene 0,64 Methanol 1,50 Micro structure can not avoid explosion a multiplication factor for pressure rise in case of explosion of around 50 is taken into account

20 Gas-Phase Alkane Nitration Challenge Using an inherent safe reactor concept with pressure resistant > 500 bar and do not forget all other parts with reaction mixture inside must also pressure resistant > 500 bar for example HEATRIC heat exchangers Lab scale down: 60 m capillary inside a hot air oven

21 Gas-Phase Alkane Nitration Results Gas-phase nitration under thermal control is within micro structured devices feasible for high selectivity inter stage feeding of O 2 is necessary to suppress side reaction of O 2 High temperature leads to the thermodynamically preferred products Avoid explosive liquid phase - strictly

22 Gas-Phase Alkane Nitration Results Reactor concept: Cascade of Heatric heat exchangers with O 2 feeding between them 100 bar 280 C 110 bar 270 C 25 C 55 C 280 C 285 C 311 C Project status: Stopped due to decrease of marked scenario from several thousends to some hundred tons per year

23 Bi-phasic Substitution (liquid-liquid phase) Corning reactor State of the art: Batch process with a complex temperature management Target: Increasing selectivity, saving cooling costs and reducing toxic hold up Idea: Using a Corning micro reactor to ensure isothermal conditions and good mixing to get a stable emulsion during the operation

24 Bi-phasic Substitution Corning reactor Temperature profiles Results: Stable emulsion formed inside Corning - fast phase separation at Corning outlet Residence time < 1min feasible Temperature 60 C higher than batch Selectivity comparable to batch process Saving of cooling shown Corning lab plant batch conti Corning Project status: Stopped - investment due to capital costs uneconomically

25 Glucose Dehydration (super critical phase) HO HO OH O OH OH H 2 O p = 400 bar T ~ 450 C HO O O OH Zeit < 1sec C1 ID: 250 µm Heating rate: K/sec Heating time: 3 30 ms C2 ID: 800 µm Reaction tube W3 ID: 800 µm Cooling rate K/sec Heat transfer coefficient: W/m²/K Quelle: Alois Kindler BASF SE, GCN

26 Yield DHD in mol% Micro Process Technology Glucose Dehydration (super critical phase) Results Dehydration of glucose under super critical conditions is feasible without formation of brown colored waste An extremly short residence time avoids plugging of the reactor ,00 0,10 0,20 0,30 0,40 0,50 0,60 0,70 VWZ_nom in s (rho=0,4) 450 C - 5% Glucose 425 C - 5% Glucose 475 C - 10% Glucose 450 C - 10 % Glucose 425 C - 10% Glucose Project stopped work up is uneconomically Lack of demand for DHD

27 Outline 1 BASF history and motivation 2 Lessons learnt Deydrogenation, Mercaptoethanol, Cyclohexane Oxidation, Propane Nitration.. 3 Applications and Conclusion Heat exchange, Evaporation, Reaction, Mixing

28 Heat exchange Heatric heat exchanger at BASF plant Source: Located on 3 rd deck of the plant Compact design small footprint Source: Presentation of R. Böhling / S.Schirrmeister Micro Process Technology, April 25, April , German-American Frontiers of Engineering Symposium Irvine, California

29 Heat exchange Micro reactor fouling Parameter Flow (t/h) T hot ( C) P (bar) Flow (t/h) T cool ( C) P (bar) Heat Duty (MW) Design Actual Heatric heat exchanger in operation at BASF since 2002 Decreasing performance after 2 ½ years Source: Presentation of R. Böhling / S.Schirrmeister Micro Process Technology, April 25, April , German-American Frontiers of Engineering Symposium Irvine, California

30 Heat exchange Gas puffing for cleaning of Heatric PCHE Source: Presentation of R. Böhling / S.Schirrmeister Micro Process Technology, April 25, April , German-American Frontiers of Engineering Symposium Irvine, California

31 Heat exchange Gas puffing for cleaning of Heatric PCHE View into feed header Offsite gas puffing (Heatric) Debris from gas puffing Source: Presentation of R. Böhling / S.Schirrmeister Micro Process Technology, April 25, April , German-American Frontiers of Engineering Symposium Irvine, California

32 Content of decomposition gases in the exhaust vapor [Vol.-%] Micro Process Technology Evaporation Background Decomposition within the miniplant evaporator at different pressure Evaporation with technical evaporator leads to a brown colored waste stream and could plug the evaporator even under vacuum conditions at mbar increasing pressure and temperature leads to non selective starting material cleavage high cost for vacuum pumps and electrical power supply Pressure [mbar] used tube bundle of a technical evaporator

33 Evaporation Micro vs. macro Evaporation at lab with a micro evaporator compared to a discontinuous distillation at atmospheric pressure 8 cm³ KIT-Cube discont. lab distillation* Temperature of exhaust vapor [ C] Decomposition fraction [%] < 0,5 50,5 * Source: Dr. Achhammer BASF SE Nearly no decomposition with a micro evaporator Up to 50 % decomposition with usual lab equipment

34 Evaporation KIT micro evaporator The micro evaporator (1 cm³ KIT- Cube) operates at 1,2-2,6 bar up to more than 1000 h without plugging 1 cm³ KIT-Cube capacity: 1 kg/h channel wide: 200 µm channel length: 1,4 cm Lab tests (8 cm³ KIT-Cube ) with cycles of evaporation and condensation showed no formation of colored byproducts fresh starting material 16-fold evaporated condensed Source: FZK Lab plant with a sectional view of the used micro evaporator capacity: 5 kg/h

35 Evaporation Micro vs. macro Characteristic data for micro and technical evaporators 1 cm³ KIT-Cube 10 l KIT-Cube tech. evaporator tube length cm 1, hyd. diameter mm 0,15 0,15 21 heat trans. coefficient W/(m²K) Heat power kw 0, residence time sec 0,1 0,1 700 The heat transfer coefficient is only secondary for the feed material decomposition within a technical evaporator The crucial point is the residence time. In a micro evaporator it is less than one thousandth compare to a technical evaporator.

36 Reaction Smale scale production BASF operates two Heatric microreactors at its Ludwigshafen site One to produce samples of up to about 20 kilograms One can manufacture quantities ranging from 1 to 50 tons for market launches of new products The microreactors are used for reactions that require high pressure, high temperatures or/and are strong exothermic The continuous mode of operation and the short reactor residence time of the reaction media ensure end products of consistently high quality Source:

37 Mixing Large scale production - BASIL TM nucleophilic catalysis/ Ionic liquid > 8 x 10 3 space time yield 8 kg m -3 h -1 batch process stirred vessel space time yield kg m -3 h -1 continuous process jet reactor Source:

38 Conclusions Micro reactors are versatile lab devices Refrain from improper generalizations Operation in explosive regime needs careful consideration Corrosion, fouling and scale up pose severe problems for production applications BASF already uses micro devices and explores further applications Source: Presentation of F. Lippert, Process BASF, Sep 7-10, 2008, Kyoto/Japan

39 Thank you for your attention