The mixSorb series of Dynamic Sorption Analyzers

The mixSorb L by 3P INSTRUMENTS is a commercial breakthrough analyzer that provides unique capabilities to investigate arbitrarily complex dynamic sorption processes in a uniquely safe and easy-to-use bench-top instrument. Industrial adsorbents such as zeolites, active carbons, silica gels, etc. can be investigated under authentic process conditions in a broad temperature and pressure range, with adjustable gas flow rates up to 40 L/min and well-defined gas compositions.

The mixSorb S provides unique capabilities to investigate novel materials, like MOFs COFs etc. by mixed gas adsorption. Novel materials are in focus of research in recent last years. These materials can have very high selectivities due to their extraordinary surface chemistry and have to be investigated by mixed gas sorption for a deeper understanding of their sorption behavior. In contrast to mixSorb L the mixSorb S is ideally designed for very small sample amounts (powders). Especially R&D groups have now the possibility to measure new synthesized materials by complex dynamic sorption processes in a wide field of different gas- and gas/vapor-mixtures by using different parameters like: pressure, temperature gas velocity/dwell times, cycle tests and much more. These experiments allows to get data, next to the effective adsoprtion performance, of kinetics, co-adsorption phenomenon or displacement effects, sorption selectivities, data of gas mixture adsorption and heat balance of the sorption process.

The mixSorb SHP (high pressure) was designed as a special device series especially for applications in the natural gas sector as well as gas storage studies on new materials under high system pressures (up to 68 bar). For the investigation of new materials for the purification of natural gas for the separation of higher hydrocarbons, for drying and further investigations pressures up to 70 bar are necessary, in order to reflect the technically relevant system pressures. In the field of gas storage studies are on the one hand the reversibility (loading and unloading of an adsorptive gas storage) and on the other hand for possible, undesirable enrichment of impurities of the gas to be stored required. For adsorptive methane storage (ANG), for example, pressure ranges up to approx. 40 bar are frequently investigated. Another application is the adsorptive purification of reforming gas for hydrogen production. Technically, these processes are carried out at system pressures of about 30 – 40 bar. Also in this case novel materials for this application should be examined in the mentioned pressure range.

Application Overview


The mixSorb is a fully automated breakthrough-analyzer. It allows the determination of breakthrough curves, the investigation of the kinetic performance of adsorbents and the investigation of co-adsorption and displacement phenomena. Furthermore, the sorption selectivities of different adsorptives can be determined and technical separation processes can be reasonably downscaled. The application of the dynamic sorption method allows the determination of single- and multi-component adsorption isotherm data.


  • Fully automated control via PC
  • Sequential adsorption and desorption experiments
  • In-situ sample preparation
  • Counter current gas flow possible for mixSorb L
  • Automated regulation of the adsorber pressure
  • Up to 4 high precision mass flow controllers, available in different sizes
  • Automated built-in gas mixing
  • Measurement of inlet and outlet gas composition
  • Monitoring of pressure drop along the adsorber
  • Built-in Thermo Conductivity Detector (TCD)
  • Optional gas analysis via interfaced Mass Spectrometer
  • Safety guard sensor for flammable gases for automatic shut down
  • Enhanced Safety by intelligent illuminated workspace

The instrument allows investigations in the following 6 fields:

Breakthrough Curves

Standard Breakthrough Curve with the dynaSorb BT

Cycle Stability testing

Cycle Stability testing with the dynaSorb BT

Competitive Adsorption

2 Breakthrough Curves in Competitive Adsorption with the dynaSorb BT

PSA emulation

PSA emulation with the dynaSorb BT

Mixture Isotherms

Mixture Isotherms with the dynaSorb BT


Chromatographic experiments the dynaSorb BT

mixSorb Manager

The user-friendly control software mixSorb Manager provides real-time control and programmable operation of all system functions, such as:

  • Gas flow rates and gas concentrations
  • Temperature ramps and dwell times for in-situ sample preparation
  • Real-time data representation
  • Manual mode control
  • Historical data trending
  • User account management (hierarchy of user levels)
  • Definition of analysis conditions and intelligent start/stop criteria
  • Configuration of arbitrarily complex analysis sequences
  • Fully automated processing of analysis sequences
  • Well-structured log files
  • Auto save function

The status of all sensors and valves, the path and direction of gas flow and all relevant system information for safe and convenient operation can be viewed at a glance on the controlling PC. The program allows furthermore to compare different experiments, easy data export, the generation of integration reports, viewing an animation of the measurement and much more.

View the following Videos to take a glimpse of this software package.

3P sim

Modeling of dynamic sorption processes is very useful for the understanding of sorption characteristics on fixed bed adsorbers. With the help of such tools, the experimental time can be drastically reduced and parametric studies can be easily performed. Within the package of the new dynamic sorption analyzer for the investigation of breakthrough characteristics, the simulation and evaluation tool is provided. This software allows the calculation of equilibrium data of mixtures from pure component isotherms, as well as the evaluation of breakthrough curves, based on mass- and energy balances. The available solver is easy to handle and can also be operated by untrained operators. The program allows:

  • Fitting of pure component isotherms with numerous isotherm models
  • Fitting a set of isotherms to determine temperature dependence
  • Prediction of mixture isotherms with IAST and other multi-component approaches
  • Advanced data reduction of dynaSorb BT logfiles
  • Import of Mass spectrometer data
  • Dynamic Simulations
  • Calculations of Breakthrough curves
  • Fitting simulated to real breakthrough curves to gain mass transfer parameters
  • Complex simulations including adsorption/desorption cycles and pressure swing adsorption

Take a look at this poster about 3P sim


The mixSorb series offers various options to create the best possible instrument configuration for your needs.

Vapor Option

While the mixSorb S and SHP can be equipped with Peltier-controlled “Bubbler”-type evaporatores, the mixSorb L features a liquid injection-type evaporator. This technology has the advantage that the liquid is dosed precisely, mixed with the gas (spray formation) and then evaporated – therefore dosing is completely independent from experimental pressure and temperature! Additionally, liquid mixtures can be incorporated, if the liquids are miscible. The knowledge of the gas and liquid flow rates gives an accurate indication of the vapor concentration/humidity, without actually measuring it.

Flow Scheme of the dynaSorb BT Vapor Option

Flow Scheme of the mixSorb L Vapor Option

Liquid dosing system for mixSorb L

  • High precision Coriolis-type Mass Flow Controller
  • Accuracy: 0.2 % of rate
  • Flow range: 0.4 to 20 g/h
  • Materials: Body: Stainless Steel 316L, Seals: FFKM
  • Pressurized with a diaphragm pump (Materials: PEEK, PTFE, FFKM)
  • Connections on the instrument: 1/8” tubing
Vacuum Option

With the Vacuum-Option, a Vacuum Pump can be connected to the instrument. A Software function is enabled, which allows the activation of the pump to evacuate the manifold and the adsorber column during pretreatments or analyses.
Besides a more effective sample pretreatment, this option allows the emulation of a VPSA-process (Vacuum-Pressure Swing-Adsorption) with one adsorber column.
You can use the “Vacuum-ready” option and your own vacuum pump or order one of two vacuum pumps together with this option.
If you want to apply vacuum only for sample pretreatment without gas flow or with very small carrier gas flow (below 100 ml/min STP), the “diaphragm pump” option is sufficient. Pressures as low as 75 mbar can be obtained.
If you want to apply low pressures under higher gas flow (up to 1000 ml/min STP), especially for the special application of Vacuum Pressure Swing Adsorption (VPSA) you should order the “scroll pump” option, which allows higher gas throughput and pressures as low as 0.02 mbar.

Adsorber Options

mixSorb L: Besides the Standard Adsorber (inner diameter 30 mm, bed height 180 mm, 4 temperature probes), there is an optional Small Adsorber (inner diameter 10 mm, bed height 50 mm, 1 temperature probe) for the mixSorb L

Adsorber Sizes

Standard Adsorber (left) and Small Adsorber (right) for the mixSorb L

We recommend to use the Standard Adsorber whenever possible, due to the more realistic fixed bed and larger measurement effects. However, the small Adsorber is designed to enable measurement with low gas concentrations on high-performance materials. Such measurements can take up to several days or weeks with the Standard Adsorber. The reduction of the sample mass shortens measurement times drastically. The small Adsorber is not designed for powder samples and samples with low performance. The particle sizes for both Adsorbers should be > 0.1 mm

Additionally, any kind of Custom Adsorber can be designed with the input of the customer (larger sizes, or sizes in between)

mixSorb S: The mixSorb S and SHP are equipped with a micro adsorber with a bed volume of less than 1 cm³. The instruments are designed in a way, that the larger adsorbers of the mixSorb L fit to the other mixSorb instruments and vice versa.

Circulating Bath

Th recirculating bath extends the temperature range of the instrument to -20 °C to 90 °C (with the bath) + 40 °C to 400 °C (with the standard electrical heating) and furthermore increases the thermal stability drastically. The device can be fully controlled with the dynaWin software.

The circulating liquid also supplies a manifold heat exchanger that cools/heats the gas mixture to the desired experimental temperature before it enters the sample cell (adsorber) to prevent non-adsorption-related temperature gradients.

The Recirculator has the following specifications

  • Temperature stability: ± 0.01ºC
  • Power consumption 2400 W (rated at 120 or 240 VAC)
  • Maximum heating power consumption: 2200 W
  • Maximum cooling power consumption: 20 °C: 915 W, 0 °C: 505 W, -20 °C: 165 W
  • Maximum flow out for fluid: 22 LPM
  • Maximum flow in for fluid: 15 LPM
  • Reservoir volume: 15 L
  • Temperature range: -20 ºC to 90 ºC
  • Maximum ambient temperature: 35 °C
  • Ambient relative humidity: Up to 80% at 30 °C in a condensation free environment
  • Dimensions: 569 x 368 x 683 mm (22.4 x 14.5 x 26.9 inches)
  • Weight: 53.5 kg (118 pounds).
Beaker Option

The recirculating beaker has be used with any type of recirculating bath (it is recommended to use the recirculator option). This special designed aluminum dewar helps to hold the sample cell (adsorber) at a very constant temperature. It can be filled with any kind of heat transfer fluid. This liquid has no contact with the primary circulating liquid. This prevents the sample cell to get in contact with the primary circulating liquid, that may contain some unwanted components.

Mass Spectrometer Option

While any additional analytics can be attached to the dynaSorb BT by default, with the Mass Spectrometer Option, a Pfeiffer® mass spectrometer (ThermoStar™ or OmniStar™) can be remote-controlled by the dynaWin software. Controlling includes turning the filaments on/off and starting/stopping data acquisition with the Pfeiffer® QUADERA® Software.
The package includes a communication cable and a capillary holder to connect the dynaSorb BT with your corresponding mass spectrometer.

Flowmeter Option

A Flowmeter can be included in the Manifold to measure the mass flow after the adsorber column. Since, at high concentrations, the mass flow, which is flowing into the column, is different from the mass flow which is flowing out of the column, until 100% breakthrough is reached. This option is necessary when you want to determine mixture equilibrium data with the dynaSorb BT.
The measured flow is always given for nitrogen equivalents at standard conditions since the gas passing the controller has a variable composition. With the help of gas factors, the integration routines of dynaWin and dynaSim correct the measured flow rates by taking into account the measured concentrations of each gas species at each point of the measurement to calculate loadings.

Kalrez Option

mixSorb L: While all MFCs come with Kalrez (FFKM) seals, the seals of the valves in the manifold are Viton (EPDM in older versions) by default. These can be upgraded to Kalrez as well (“Kalrez” option). Other sealing materials on request. The Standard working seals for the sample cell are made of copper (CF and VCR seals). There are other sealing materials (Teflon, Viton, Stainless steel) on request.

mixSorb S and SHP: All MFCs come with FFKM seals, the valves are equipped with PEEK and FKM seals.