Measuring the Activity and Selectivity of Catalysts

Interview conducted by Alexander ChiltonJul 10 2015

In this interview, Simon Yunes, Senior Application Scientist at Micromeritics, talks to AZoM about using the Micromeritics Flow Reactor (FR) Series to measure the activity and selectivity of catalysts.

Could you provide our readers with an overview of the Micromeritics Flow Reactor and how it works?

The Micromeritics Flow Reactor is an automated, high-pressure, fixed-bed catalytic reactor that includes all valves and process layout inside a hot box to efficiently preheat reactants and to avoid condensation of volatile products. This equipment has been designed as a universal basic instrument that can be modified; it features various configurations and options for upgrading the unit to meet the researcher requirements.

The basic unit FR-100 includes the reactor (up to 800 ^oC) and valves inside the hot box, 3 mass flow controllers (MFCs), a micro-regulation pressure control system (up to 100 bar +/-0.1 bar standard), and an optional high-pressure liquid/gas separator with very low dead volume. All common elements are designed to work in continuous mode. An automatic six-way valve makes it possible to bypass the reactor before a reaction starts while stabilization and feed analysis are taking place.

The main advantage of the FR-100 is its reproducibility, a result of the patented control systems specially developed for this particular use.

Why is it important to test a new catalyst for activity and selectivity?

After preparing and characterizing a catalyst at micro scale (few mg only) it must be tested for its activity and selectivity for its intended reaction. If undesirable products are obtained, the catalyst can once again be prepared without having to spend a large amount of money. In other words, the FR series microreactors allows testing of small quantities of catalysts that can yield a very effective and economic catalytic process.

Could you provide some examples of reaction types which the FR-100 can accommodate?

Both simple and complicated reactions can be carried out using the FR-100 microreactor. Hydrotreating, isomerisation, hydrocracking, hydrogenation, and reforming are a few examples.

The most complicated reaction carried out by the FR-100 microreactor is Fischer-Tropsch synthesis where the product is a mixture of two non-miscible liquids, water and hydrocarbons. The FR-100 can separate the water from the hydrocarbons online.

What are the main advantages of using the FR-100 compared to conventional systems for collecting catalyst activity?

Reactors that were used in the past up to just a few years ago were primarily made of glass and could not work at high pressure. Currently, activity testing must simulate the high pressure and temperature of industrial conditions. Although other high-pressure reactors are now available, product collection still remains to be an issue.

While other systems must collect product for days or even weeks before compositional analysis can be conducted, the FR-100 allows the collection and analysis of product almost instantaneously. This means that the initial activity and all subsequent activity is monitored and used for kinetic studies. Collecting products online allows the operator to follow the activity and selectivity of the catalyst as a function of analysis time.

Could you outline the different reactor configurations which are available?

There are three mains configurations available for the Micromeritics Flow Reactor. The first configuration is called the FR-50 which is supplied with one furnace and  reactor that can operate at atmospheric pressure, and two gas feeds.  It is a basic unit that can be upgraded to work up to 100 bar pressure and with fully automatic operations. 

The second option, the FR-100, differs from the FR-100 mainly by adding an extra gas feed, it can work up to 100 bar (optional 200 bar) and has a high-pressure liquid/gas separator. The operations with the FR-100 are fully automatic.

Finally, the third option, the FR-200, features two furnaces and two reactors which can be operated in parallel or in series. This allows the same operation as the FR-100 with the added ability to regenerate the spent catalyst on one reactor while the other performs standard activity testing. 

Does the Micromeritics Flow Reactor comes with any optional features?

The FR series can be updated to run with many different possible configurations. For example, if a reaction requires liquid reactants it is advisable to flow the liquid from the bottom of the reactor instead of from the top. Adding a six-way valve to reverse the flow ensures complete wetting of the catalyst bed.

Additionally, adding a calibrated volume loop with a selection valve allows for characterization of the catalyst at high pressure by the pulse chemisorption technique.  This option is called the Micro Catalyst Characterization and Testing Center (MCCTC).

Which are the main industries which benefit from using this instrument?

All research centres that develop catalysts for the oil refineries, catalyst manufacturers, chemical engineering laboratories, pure chemical schools, petrochemistry industries and many others.

In which countries do you currently distribute of the Micromeritics Flow Reactors to? Are there any plans to expand the distribution to other areas of the world in the future?

Micromeritics distributes the FR worldwide.

Where can our readers find out more information about the Miromeritics Flow Reactor?

At www.micromeritics.com you can find informative videos, brochures, application notes, publications, and journals with additional information about the FR microreactors. 

About Simon Yunes

Simon Yunes received his B.S. degree in Chemistry from the Central University of Venezuela.  He received both his M.S. and Ph.D. degrees in Physical Chemistry from Catholic University of Louvain, Louvain-La-Neuve, Belgium.

Simon is recognized worldwide for his contribution to the field of adsorption and the application of adsorption techniques to the characterization of solids, particularly catalysts.

Simon joined Micromeritics in May 1984, where he held the position of Senior Application Scientist, conducting experiments on adsorption, assisting the development of new products and writing application notes. His primary function at Micromeritics was to support customers worldwide with their applications, and to find or assist in developing new technologies to meet the needs of customers.

From 1992 to 1996 Simon managed a Micromeritics laboratory at the Venezuelan Research Institute (IVIC) in Caracas, Venezuela. From 2004 to 2009 Simon supervised the Catalyst Characterization Laboratory at the Venezuelan Petroleum Institute INTEVEP. In September 2009, Simon returned to the Micromeritics headquarters in Norcross, Ga, where his primary responsibility is the support of customers worldwide in their application of Micromeritics technologies.