Agitated Cell and Tube Reactors PIN NL, May 11 th 2011

AM Technology

Engineering Chemistry

Agitated Cell and Tube Reactors

© AM Technology May 2011 Patented Technology

www.amtechuk.com

PIN NL, May 11th 201113:45 to 14:20

Robert Ashe AM Technology

AM Technology


AM Technology

• Based in the UK

• Founded in 2000

• Manufacture chemical reactors

• Strong focus on innovation


www.amtechuk.com

AM Technology


Agenda

• Static mixing versus dynamic mixing

• Coflore Agitated Cell/Tube Reactors

• Results

Agenda


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Continuous reactor (with orderly flow )

ab

c

a

b

c

Orderly (plug) flow

Process intensification


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Batch reactor

Orderly (plug) flow

Process material travels through and leaves the

reactor in the same order that it enters

• Optimum reactor capacity

• Improved reaction time control

• Higher yield

• Higher purity

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Flow reactors – controlling cost is a key objective

Minimise pressure drop

Reducing the pressure drop reduces pump costs, especially for corrosive fluids.

Minimise tube length

Short large diameter reactor tubes are cheaper per unit volume than long

small diameter tubes. Large diameter tubes can also have significantly longer

service lives than small diameter tubes


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Two phase mixtures

Reliable handling of two phase mixtures (where applicable), is essential for

minimising disruption and waste

Versatility

For cost effective operation in a multi step, multi product manufacturing

environment, flow reactors need to be multi purpose

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ab

c

In small tubes (typically < ½ mm diameter), mixing and orderly flow are not

dependent on fluid velocity. Small tubes however have high pressure drop,

high cost per unit volume and poor handling capabilities for two phase

mixtures

In large tubes, mixing and orderly flow rely on fluid changing direction as it

flows through the reactor. This can be achieved with baffles, static mixers

Statically mixed reactors


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a

bc

flows through the reactor. This can be achieved with baffles, static mixers

or turbulent flow. Axial velocity becomes a quality critical parameter.

Mixing and orderly flow is dependent on fluid velocity through the channel

• Long tube lengths with long reaction times

• Limited flexibility and high minimum throughputs

• High pressure drop

• Poor handling of two phase mixtures

• Poor mixing with long tube lengths

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Dynamically mixed reactors

a

b

a

b

Dynamic mixing generates good mixing

independently of net fluid velocity

Stage separation (or long tubes)

prevents back mixing independently of

net fluid velocity

c

c


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Good mixing and orderly flow is achieved independently of tube diameter, tube

length or fluid velocity through the reactor

• Good mixing and orderly flow independently of fluid velocity

• Short tube lengths

• High flexibility

• Low pressure drop

• Good handling for two phase mixtures (due to large diameter and good mixing)

b net fluid velocity

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Reactor type Tube

diameter

Tube length

per litre

Minimum flow

for turbulent

flow*

Pressure drop , 30

second reaction at

minimum flow

mm m litres/hour bar

Micro 0.5 5,090 3.3 1880

Flow conditions for turbulent flow

Ca

n b

e r

un

un

de

r la

min

ar

flo

w c

on

dit

ion

s

Dynamically mixed flow reactors deliver substantial cost advantages

through shorter tubes, lower pressure drop and flexibility


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Micro 0.5 5,090 3.3 1880

Static mixed tube 1 1,270 6.6 104

Static mixed tube 5 51 33 0.15

Static mixed tube 10 13 66 0.01

Static mixed tube 40 <1 263 0.0004

Dynamic mixed tube 40 <1 0 <0.0001

Ca

n b

e r

un

un

de

r la

min

ar

flo

w c

on

dit

ion

s

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40

50

60

70

80

90

100

Yie

ld (

%) Stage 8

Scale up design is simpler in multi stage dynamically mixed flow

reactors but attention must be given to kinetics. The reactor is

treated as a series of equal conversion stages


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0

10

20

30

40

0 1 2 3 4 5 6 7 8 9 10

Volume through the reactor (litres)

Stage 4

4 8

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20

30

40

50

60

70

80

90

100

Co

nv

ers

ion

(%

)

First CSTR stage

Slope = max yield per stage/minimum stage volume

Where the reaction rate or heat evolution exceeds the minimum size

constraints of a stirred stage, micro reactors can be combined with

the dynamically mixed system


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0

10

0 1 2 3 4 5

Volume through the reactor (l)

Micro reactor

50% of reaction 3%

of reactor volume

Stirred tanks in series

50% of reaction 97% of reactor

= >95% reduction in tube length and pressure drop)

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• Sealing problems (cost, leaks, buffer fluid leak, pressure limits)

• Shaft stability problems (with long axial shafts)

Conventional rotating stirrers are difficult to use in flow reactors


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• Shaft stability problems (with long axial shafts)

• Centrifugal separation problems (two phase mixtures)

• Baffle design problems (baffles difficult to fit)

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Coflore - an alternative method of mixing

Coflore reactors use transverse shaking to generate mixing


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Coflore - an alternative method of mixing

• High mixing efficiency (radial)

• No baffles (self baffling)

• No seals or magnetic couplings

• No centrifugal effects

• No shaft stability problems

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Pro

du

ct f

low

Reaction cell

Inter-stage

channel

Discharge

Agitator

In small systems the reaction stages are cut within a monolithic block


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Pro

du

ct f

low

Feed

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The bench top shaker platform can handle a range of reactor blocks


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Standard 100 millilitre

reactor block

Standard 10 millilitre

reactor block

Counter current

reactor block

Patents pending

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Interchangeable agitators are used for different applications

Spring agitator for two Ceramic agitator


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Control RTD and

surface to volume

ratio with different

diameter agitators

Spring agitator for two

phase mixtures

Basket agitator for

handling catalyst

Ceramic agitator

Hastelloy agitator

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• Operating capacity - 1 to 10 litres

Industrial scale Coflore reactors used tubes with free moving mixing elements

Patents pending


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• Operating capacity - 1 to 10 litres

• 10 temperature control zones

• High design pressure/temperature


• High mixing efficiency

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Mixing

Homogenous fluid - comparable to >4m/s in static mixer

Immiscible fluids - comparable to 400 rpm in a 1 litre

Gas/liquid comparable to >600 rpm in a 1 litre batch vessel

Coflore performance

Tests have consistently delivered good mixing, good handling of two phase

mixtures and low pressure drop


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Two phase mixtures

Slurries, immiscible liquids, gas/liquid mixtures

Pressure drop Generally less than 0.01 bar

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0.6

0.7

0.8

0.9

1

Co

nv

ers

ion

Coflore 10 to 50 reaction stages Zero back mixing with

>3 hour reaction time

Orderly flow is maintained by using multiple stages + tube length


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0

0.1

0.2

0.3

0.4

0.5

0.6

0 20 40 60 80 100

Co

nv

ers

ion

Volume through the reactor

Alkali

Neutral solution

+ pH indicator

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Test results


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2 stage reaction for nanoparticle synthesis

Step 2 : nanoparticle synthesisGas formation

Two stage reaction with gas and solids


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Step 1 : gold solution + ligand

Gas formationClumps of nanoparticles

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Fed-batch Fed-batch ACR

A + B → PB + B → unwanted products

B + P → unwanted products

Good scale up characteristics for mixing sensitive reactions

Coflore

Homogenous reaction

High yield, low pressure drop

Quick to configure

0.1 – 100 litres per hour


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Fed-batch Fed-batch ACR T ,°C 20 20 20 Volume , ml 1-2 2000 60 Reaction time , minutes 5 10 5 Yield 90 % 64 % 94 %

5 litres an hour

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60.0

80.0

100.0

Con

vers

ion,

%Bio-catalytic oxidation of D Amino acid

1 L batch, 14 g/l

ACR, 14 g/l

Oxidation of D Amino acidImproved reaction rate, no blockage

Lab scale - mixing sensitive reaction with gas, liquid and

solids


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BIOCHEMIST

Gas/liquid/solid

Enzymes loaded as whole cells

0.0

20.0

40.0

0.00 5.00 10.00 15.00 20.00

Con

vers

ion,

%

Reaction Time, h

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60

80

100

Co

nv

ers

ion

, %

Bio-catalytic oxidation of D Amino Acid

ATR, 7g/l, ala, 0.25l/min

Batch, 7g/l, ala, 500rpm,

0.25l/min

First results at the 10 litre scale with slow agitation speed.Reactor length 4 metres

Industrial scale - mixing sensitive reaction with gas, liquid

and solids


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0

20

40

60

0 2 4 6 8

Co

nv

ers

ion

, %

Reaction Time, h

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Coflore reactors have handled a wide range of reactions

─ Suzuki reaction

─ Hoffmann reaction

─ Grignard reaction

─ Biocatalysis

─ Nitration

─ Hydrogenation

─ Bourne reaction

─ Oxidation of D Amino acid with live cells and oxygen

─ Emulsion polymerisation

─ N-iodomorpholinium hydroiodide salt

Coflore – test results


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─ N-iodomorpholinium hydroiodide salt

─ Nano particle synthesis

─ Acid treatment of wood pulp (10% by weight, ≈ 30% by volume)

─ Counter current extraction

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1. Dynamic mixing combined with stage separation deliver:

• Flexibility

• High capacity per unit length in short tubes

• Excellent mixing and good plug flow


• Good handling of two phase mixtures

• Inherently simpler to scale up

2. Used in combination with a micro reactor, CSTR’s can deliver optimum

performance and cost for a wide range of reaction types

Conclusion


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3. Historically, dynamically mixed flow reactors have been difficult to use due to the

cost and technical challenges of employing multiple dynamic mixers in small cells

and long tubes. The Coflore reactor addresses these problems and can be used for

a broad range of applications.

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Thank you


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[email protected]

AM Technology

Telephone +44 (0) 1928 51 54 54

E-mail: [email protected]

Documents

Agitated Cell and Tube Reactors PIN NL, May 11 th 2011