Multiple Reactor System LEMRS-5000 Series

Stirred Batch Reaction Vessel

This multiple reaction system has been designed around a vessel with 75 mL total volume. This will accommodate between 15 and 40 mL of liquid reactants which is close to the minimum volume appropriate for heterogeneous catalytic reactions.

The vessel valves and accessories are designed for maximum operating pressures up to 3000 psi at operating temperatures up to 300 °C. A system with 45 mL vessels is also available.

Stirring System

All six vessels are stirred with a single magnetic stirrer system specifically designed and built for this application. The magnetic drives and fields are focused on the stirrer bars within each vessel. High strength compact magnets are used to provide coupling forces which will operate through the heaters and vessels. The stirring speed of the stirrer bar is variable from 0-1200 rpm. All vessels will have the same stirring speed during a single run of the apparatus. This arrangement ensures that the difference in reaction rates between vessels run in parallel are due to set conditions other than variations in stirrer speed.

Heaters

The external heaters surround the vessel walls for rapid and uniform heating and temperature control. Each vessel is individually temperature controlled. The 250-watt heater used on each vessel produces heating rates up to 15 °C per minute. An optional reactor cooling support rack is available for air-cooling.

Operating Modes

The Series 5000 Multiple Reaction System provides an apparatus for running up to six reactions in parallel to build a database for comparing and optimizing operating conditions. The user can design experiments to:

• Run all reactions at the same temperature and pressure while varying catalyst loading or reactant concentrations to optimize these parameters.
• Run all reactors with identical loads varying pressures at a common temperature to study the effect of pressure on reaction rates.
• Run individual reactors with individual loading and temperature and pressure to screen multiple options for activity.

A comparison of the plots of pressure drop versus time within the reactors running under parallel conditions will usually be the most useful means of measuring reaction rates and comparing operating conditions. The internal thermocouple also provides a means of detecting temperature changes due to exothermic reactions.

Reactor Options

As Company customers have come to expect with our line of laboratory pressure reactor equipment, these reactors are offered with a number of options which permit the user to configure the system to their reactions and intended operating conditions. These options include:

O-ring or Flat Gasket Seals. Vessels with O-ring seals are closed by simply tightening the screw cap down hand tight. The maximum operating temperature will depend upon the O-ring material. When equipped with FKM (Viton®) O-rings operating temperatures up to 225 °C are permitted. By substituting FFKM (Kalrez®) O-rings this limit can be raised to 300 °C. Careful consideration of chemical compatibility must also be given when selecting O-ring materials. PTFE gaskets can be used to temperatures up to 300 °C and offer virtually universal chemical compatibility. Six compression bolts are used to develop the sealing forces on the PTFE gaskets in this design.

Head Configuration. Each reaction vessel is equipped with an inlet valve, exhaust valve, safety rupture disc, and pressure transducer in addition to an internal thermocouple. Vessels can be modified to include a dip tube for liquid sampling or a cold finger for cooling. The user can choose to have the valves, transducer and rupture disc mounted on a multi-port adapter connected directly to the vessel head, or remotely mounted on the back panel.

• Head Mounted. The head mounted design makes it possible to remove the pressurized vessels from the heater/stirrer assembly or to prefill the vessels in a remote location. PEEK flexible tubing with a quick slip connector is provided for each vessel for inlet of gas. Tubing is easily removed after gas fill.
• Panel Mounted. The remote panel mounted arrangement connects all the pressure inlets/ outlets to each vessel with a single PTFE lined stainless tubing. Alternate stainless steel tubing is offered if required. In the panel mount valve configuration the gas inlet tubing generally remains attached to the vessels during operation.

Materials of Construction. Type 316 Stainless Steel is the standard material of construction for both the vessel with its wetted parts and the gage block assemblies exposed to vapors. For investigators working with systems containing strong mineral acids or other more corrosive systems these vessels can be made of most of the standard materials of construction.

Stirrer Configuration. Stirring is accomplished by use of either PTFE coated or glass coated magnetic stirrer bars.

Thermocouple Configuration. Thermocouples are mounted inside the vessel for the best temperature monitoring and control. The thermocouples are protected by stainless steel sheaths which are inserted into a protective thermowell. These thermowells make it easy to install and remove thermocouples from the vessels, and also provide additional chemical and mechanical protection for the thermocouple. We also offer an external thermocouple option with the thermocouples positioned in contact with each cylinder wall.

Gas Manifold. The brass gas inlet manifold can be designed to handle both a purge gas, usually nitrogen, and a reactant gas, usually hydrogen. This can be set up to automatically fill each vessel to the same initial pressure or to manually fill each vessel to a unique operating pressure. This gas manifold can also be supplied in T316SS to meet more corrosive requirements.

Gas Burettes. For applications where gas consumption measurement is important, optional high pressure gas burettes can be provided. These burettes allow monitoring/calculation of the number of moles of gas consumed during a reaction.

4871 Process Controller

The Series 5000 Multiple Reaction System is controlled by a dedicated 4871 Process Controller. A detailed description of this controller is found in our 4871 Process Controller section.

For this application the controller is set up to provide:

• Temperature monitoring and PID control of each individual reactor.
• Pressure monitoring of each individual reactor.
• Data logging of temperature and pressure in each reactor.
• Control and logging of the common stirring speed of the reactors.

The controller provides Ramp & Soak programming for individual reaction vessels, digital inputs and outputs for interlocks, alarms or other safety features, and additional analog and digital inputs and outputs to control flow meters or other accessories which might be added at some future date. The user’s control station is a PC running any current Windows operating system. A simplified graphical user interface has been designed for the control and monitoring of the Series 5000 Multiple Reaction System. The PC is used strictly as the user interface and data logging module. All control actions are generated in the 4871 Process Controller (not the PC).

Specifications

Manual.pdf