Precision and accuracy in fluid and pressure control for parallel reactors

The key to success in small scale parallel reactor systems is to be able to test catalysts at exactly the same process conditions over multiple tests, and to translate these directly into commercial values. The two crucial ingredients for succeeding with that approach are both precision and accuracy. Interestingly, we often come across common misunderstandings or mix-ups of these two concepts. While accuracy is the closeness of a measured value to a known value, precision is the closeness of more measurements to each other as shown in the picture.

Translating these concepts into parallel testing systems, accuracy is provided by the total flow of a Massflow controller, while the precision is the equal distribution between the reactors to achieve a true parallel system. Since the early days of high-throughput parallel reactor systems, the flow distribution is based on the use of physical flow restrictors, e.g. narrow bore tubes (capillaries) In this way, a common feed flow can be distributed to parallel reactors. However, the use of capillaries poses its own challenges because it requires carefully chosen lengths for each capillary to ensure equal pressure drop so as to achieve a similar flow rate to each reactor channel. This can be cumbersome and implies a lot of manual labor work as each flow needs to be verified, preferably with the exact gas mixture.

Microfluidics – The easy way to precisely control your distribution

In Flowrence, we make use of our proprietary high precision microfluidic flow distributor chips. Each microfluidic chip is tested in-house for a guaranteed flow distribution, with the precision between the channels guaranteed < 0.5%RSD.

The installation of a microfluidic distributor is a matter of minutes. Using the right pressure drop, the chip will give the user the best dynamic range and allows for great flexibility in types of feed and flow ranges.

How to solve the issue of catalyst pressure drop influencing the feed distribution?

When long tests are to be executed, a common faced challenge is to guarantee the precision of the gas flow distribution over the duration of the test, when possible catalyst pressure drop effects or blockages in a reactor can occur over time. In traditional systems, the change in pressure drop over reactors will have a direct impact on the precision of the feed distribution as a higher reactor inlet pressure in one reactor will result in a decline in feed supply to that reactor, while other reactors will receive more flow. The resulting effects are even more pronounced at small scale testing. Such testing systems cannot compensate for this, which results in reduced testing precision.

Avantium has invented the individual Reactor Pressure Control – RPC – to overcome that problem. The RPC reactor pressure controller module allows accurate measurement and precise control of the individual reactor pressures to ensure an equal reactor inlet pressure between all reactors at all times as shown on the picture below. This is achieved by using the measured reactor inlet pressure and adjusting the control valve at the exit of each reactor to compensate for this with its patented technology (WO2014062055 and WO2014062056).

The benefit for the operator is twofold.

  1. If the pressure drop drifts during a test, the RPC can actively compensate for this to ensure an equal inlet pressure for each reactor, ensuring the continued precise functioning of the microfluidic gas distribution.  This advantage is even greater in the case of low-pressure processes such as Oxidative Methane coupling or Reforming, because in such cases even small variations in reactor pressure can have a large impact on the yields of products.‌
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  2. In addition, the RPC uniquely provides the user with a record of the pressure drop over each reactor at all times. This delivers important information about a potential plugging behavior.

Avantium’s microfluidics in combination with our RPC and Tinypressure are the tools to guarantee the most precise feed distribution in the industry. This allows our customers to distinguish even small catalysts activity differences, accurately and precisely required for the right decisions.

Flowrence® products specifications

Reactor Section

Easy and quick reactor exchange system. Possibility to use quartz reactors at high pressure.

1 block of 4 reactors

HT = High Temperature max. 800°C nominal, limited to 925°C (<0.5°C reactor to reactor deviation)

4 blocks of 4 reactors

HT  or MT = Medium Temperature max. 525°C (<0.5°C block-to-block deviation)

16 reactors with iRTC

individual Reactor Temperature Control
max. 550°C (<0.5°C reactor-to-reactor)

4 reactors with iRTC

individual Reactor Temperature Control
max. 550°C (<0.5°C reactor-to-reactor)

Temperature Ranges (°C)

100 – 800°C
up 925°C (Option)

50 – 525°C
100 – 800°C
up 925°C (Option)

50 – 550°C

50 – 550°C

Reactor Types

L= Length
OD= Outer Diameter
ID= Inner Diameter
SS= Stainless Steel (< 550⁰C)
Qz= Quartz (< 925⁰C)

L 300 mm 561 mm
OD 3 mm 6 mm
ID SS 2 / 2.6 mm 2 / 3 / 4 / 5 mm
ID Qz 2 mm 2 / 4 mm
300 mm 561 mm 561 mm
3 mm 3 mm 6 mm
2 / 2.6 mm 2 / 2.6 mm 2 / 3 / 4 / 5 mm
2 mm 2 mm 2 / 4 mm
561 mm
3 mm
2 / 2.6 mm
2 mm
561 mm
3 mm
2 / 2.6 mm
2 mm

Maximum Catalyst Bed Length

(isothermal zone tolerance ± 1°C)
Note: isothermal length is dependent on the temperature range

300 / 3 HT 561 / 6 HT
>120 mm @ 450°C >200 mm @ 500°C
>90 mm @ 800°C >150 mm @ 800°C
>140 mm @ 925°C
300 / 3 HT 561 / 3 MT 561 / 6 HT
>120 mm @ 450°C >310 mm @ 450°C >200 mm @ 500°C
>90 mm @ 800°C >150 mm @ 800°C
>140 mm @ 925°C
561 / 3 MT iRTC
250°C ±0.5°C 41cm (4reactors)
350°C±0.5°C 38cm (4reactors)
550°C±0.5°C 28cm (4reactors)
3 reactors at 550°C, 1 reactor 350°C:
550°C=27cm 350°C=41cm ±0.5°C
561 / 3 MT iRTC
250°C ±0.5°C 41cm (4reactors)
350°C±0.5°C 38cm (4reactors)
550°C±0.5°C 28cm (4reactors)
3 reactors at 550°C, 1 reactor 350°C:
550°C=27cm 350°C=41cm ±0.5°C

Catalyst Volume (mL)

(isothermal zone)

0.2 - 0.6 mL 0.4 - 2.0 mL
0.2 - 0.6 mL 0.4 - 1.0 mL 0.4 - 2.0 mL
0.4 - 1.0 mL
0.4 - 1.0 mL

Pressure Ranges (barg)

2 – 80 barg
0.5 – 180 barg (option)

2 – 100 barg
0.5 – 180 barg

2 – 80 barg
0.5 – 180 barg

2 – 20 barg
2 – 50 barg (option)

Reactor Pressure Control

Advanced control RSD ±0.1 barg at reference conditions (gas phase only and 20 barg). For trickle flow Advanced control RSD ±0.5barg.

Standard (±0.5 barg)
Advanced (±0.1 barg) (option)

Standard (±0.5 barg)
Advanced (±0.1 barg) (option)

Advanced (±0.1 barg)

Advanced (±0.1 barg)

Gas Feed Lines

(#Gas Feeds)

Up to 6 + Diluent gas

He, Ar, N2, H2, CH4, CO2, C2H4, C2H6, O2/Inert (≤5%), CO, Other gases

Up to 7 + Diluent gas

He, Ar, N2, H2, CH4, CO2, C2H4, C2H6, O2/Inert (≤5%), CO, Other gases

Up to 7 + Diluent gas

He, Ar, N2, H2, CH4, CO2, C2H4, C2H6, O2/Inert (≤5%), CO, Other gases

Up to 6 + Diluent gas

He, Ar, N2, H2, CH4, CO2, C2H4, C2H6, O2/Inert (≤5%), CO, Other gases

Online Analysis

Full integration GC, MS , GC/MS with data visualisation (option)

Full integration GC, MS , GC/MS with data visualisation

Full integration GC, MS , GC/MS with data visualisation

Full integration GC, MS , GC/MS with data visualisation

Liquid Feed

 Split feeding 8 + 8 reators (option)

Pump-Coriolis dosing system
(ambient, cooled)

Pump-Coriolis dosing system
(ambient, cooled, heated 80°C)

Pump-Coriolis dosing system
(ambient, cooled, heated 80°C)

Pump-Coriolis dosing system
(ambient, cooled, heated 80°C)

Liquid Distribution

Microfluidic Distribution
(4-channel glass-chip)

Microfluidics Distribution
(4x4-channel glass-chip)
(16-channel glass-chip)
Active Liquid Distribution (option)
(with automatic isolation valves)

Active Liquid Distribution
(with automatic isolation valves)

Microfluidic Distribution
(4-channel glass-chip)

Liquid Sampling

(G/L Separation)

Parallel liquid sampling (4 x 20ml vials) with sequential on-line gas phase sampling (option)

Automated liquid sampling (4 rows x 16 vials x 8ml) with sequential on-line gas phase sampling (option)

Automated liquid sampling (4 rows x 16 vials x 8ml) with sequential on-line gas phase sampling (option)

Parallel liquid sampling (4 x 20ml vials) with sequential on-line gas phase sampling (option)

Reactors Effluent Handling

(Off-line Analysis Connection)

Full heated circuit up to 180°C with sequential on-line full gas phase sampling (option)

Full heated circuit up to 200°C with sequential on-line full gas phase sampling

Full heated circuit up to 200°C with sequential on-line full gas phase sampling

Full heated circuit up to 200°C with sequential on-line full gas phase sampling

Offline Analysis

Integrated Workflow: SimDist, total S/N, liquid density, balance, label printer, barcode (option)

Integrated Workflow: SimDist, total S/N, liquid density, balance, label printer, barcode

Integrated Workflow: SimDist, total S/N, liquid density, balance, label printer, barcode

Integrated Workflow: SimDist, total S/N, liquid density, balance, label printer, barcode

Waste Handling

Ambient temperature
Heated wax trapping (option)

Ambient temperature / Cooled containers / Heated compartment (wax trapping, heavies)

Ambient temperature / Cooled containers / Heated compartment (wax trapping, heavies)

Ambient temperature / Cooled containers / Heated compartment (wax trapping, heavies)

Safety

Gas sensors and control box (CO, LEL, VOC)

Gas sensors and control box (CO, LEL, VOC)

Gas sensors and control box (CO, LEL, VOC)

Gas sensors and control box (CO, LEL, VOC)

Flowrence® Software

Flowrence® recipe builder, control & database builder

Flowrence® recipe builder, control & database builder

Flowrence® recipe builder, control & database builder

Flowrence® recipe builder, control & database builder

Microfluidics modular gas distribution

Unrivalled accuracy in gas distribution with patented glass-chips for 4 and 16 reactors, with a guaranteed flow distribution of 0.5% RSD. Quick exchange of glass-chips for different operating conditions. Flexibility to cover a wide range of applications.

TinyPressure glass-chip holder with integrated pressure measurement

Compact modular design for gas and liquid distribution. No high-temperature pressure sensors required. Quick exchange of the microfluidic glass-chips, without the need for time-consuming leak testing.

Tube-in-tube reactor technology with effluent dilution

Unique tube-in-tube design with easy and rapid exchange of the reactor tubes (within minutes!). No need for any connections. Use of inert diluent gas (outside of reactor) to maintain the pressure prevents dead volumes and back flow. Possibility to use quartz reactors at high pressure applications.

Automated liquid sampling system

Programmable, fully automated liquid product sampling robot for 24/7 hands-off operation. Robot equipped with a compact manifold aiming at depressurizing the effluent immediately after each reactor to atmospheric pressure. Eliminates the use of high pressure valves.

Reactor Pressure Control (RPC)

The most accurate and stable pressure regulator for a 16-parallel reactors with just ±0.1bar RSD. The RPC uses microfluidics technology to regulate the pressure of each reactor, maintaining equal distribution of the inlet flow over the 16 reactors.

Auto-calibrating liquid feed distribution, measurement, and control

Distribution of difficult feedstocks e.g., VGO, HVGO, DAO. Liquid distribution 0.2% RSD, making it the most accurate liquid distribution device on the market. Option to selectively isolate each reactor.

Single-Pellet-String-Reactors (SPSR)

No dead-zones, no bed packing & distribution effects. The catalyst packing is straightforward and does not require special procedures. A single string of catalyst particles is loaded in the reactors avoiding maldistribution, eliminating channeling and incomplete wetting.

EasyLoad®

Unique reactor closing system with no connections. Rapid reactor replacement minimizing delays, improving uptime and reliability. Stable evaporation by liquid injection into reactor.

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+31 (0)20 586 8080

Zekeringstraat 29
1014 BV Amsterdam
The Netherlands

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