From the laboratory beaker to bulk; the scale up of a process

Each industrial process starts on laboratory scale to define the important parameters efficiently. These parameters might be pressure, temperature, flow but also cost efficiency and standing times. The process with the highest yield is not automatically the most efficient one. For example in catalysis or exhaust/raw gas purification it is very important to find the economically best materials and parameters. From the laboratory beaker to bulk is the process which starts at a microscale and ends with a fully operating industrial process. In between often a pilot stage is included.

Biogas purification testing

In Pressure Swing Adsorption systems (PSA), adsorption processes are used for the purification of bio- or natural gas. Thereby, the preferred adsorption of CO2 by zeolites or carbon-based sorbents is used to generate highly pure methane. This methane can be used for heat and power generation, offering an alternative to fossil fuels. Particularly in case of pressure swing adsorption systems, new materials are continuously being developed and evaluated, promising optimized efficiency caused by better sorptive separation properties. Laboratory scale studies are of special interest as the potential of new materials as well as the associated economics of corresponding industrial processes can be assessed in advance.

Breakthrough Measurements on Laboratory Scale

The Rubolab GmbH has been a spin-off from Rubotherm GmbH, Germany and the Ruhr-University in Bochum, Germany. Rubolab offers a broad versified portfolio of different adsorption measurement instruments. As Managing Director of Rubolab, I developed the worldwide first manometric high pressure adsorption screening instrument in 2012. During the last years, dynamic adsorption measurement instruments, so called Breakthough Analyzers, have gained increasing importance. In this context, Rubolab offers costumized instruments for the evaluation of novel sorbents in smallest amounts (MiniBTC series).

High pressure resistant vessels are filled with the materials which have to be analyzed. Afterwards this adsorber bed is pressurized using defined gas flows. A corresponding flow sheet of the instrument is shown in the following figure.
 

In the example above, the sorptive separation of CO2 and CH4 is investigated. In this case, CO2 is adsorbed by the material while the gas is flowing through the fixed bed. A high-purity methane stream is recovered at the top end of the adsorber column.

Three temperature sensors are positioned at different heights within the adsorber column. Due to the exothermic adsorption process, a temperature change within the adsorber bed can be detected, indicating the so-called Mass Transfer Zone (MTZ) going through the fixed bed. When this zone reaches the adsorber head, a corresponding breakthrough can be observed by using downstream gas analysis. Thereby the measured CO2 concentration in the product stream approaches the CO2 concentration of the feed stream. In larger industrial systems the adsorber should be regenerated at this time. This kind of experimental data provides information about adsorption capacities of the substances being investigated.

Mass Flow Controller and pressure regulation valves

For the highly accurate controlling of mass flows and downstream pressures these instruments are equipped with Bronkhorst mass flow controller and pressure regulation valves. In particular devices of the newest generation of mass flow controllers, the Bronkhorst EL-FLOW Prestige series, are used in corresponding laboratory instruments for high end accuracy and versatility. In other devices where the size is of high importance, the Bronkhorst IQ+FLOW series is used to take advantage of it’s very compact size and the possibility to set up small manifolds.

Mass Flow Controller of the EL-FLOW Prestige Series

EL-FLOW Prestige mass flow controllers and meters are highly versatile instruments with their onboard database for gases and mixtures. So it is easy to react on changing customer needs without the necessity to purchase another instrument, when the test gas changes. The Prestige guarantees highly accurate and reproducible gas flow due to an automatic temperature correction, newly designed sensor and valve technology.