Pressure Control - High-Throughput Zeolite Adsorption Testing System

ILS designed a system for performing high-throughput kinetic adsorption testing studies on zeolite powders. The system is characterized by high-pressures (250 bars) that result largely from the very small zeolite powders used (0,1 micron). The small particle size is required to eliminate pore-volume diffusion effects.

A Badger valve was required, to maintain the reactants in either the supercritical or liquid phase downstream of the zeolite reaction beds.

The reactors were microreactors containing approximately 100-300 milligrams of zeolitic powder.

In order to be able to measure sharp breakthrough curves using on-line fast liquid GC, excellent pressure regulation with a low dead volume was required. In addition, implementation of supercritical media exhibiting strong Joule-Thompson cooling effects complicates the control problem.

ILS implemented a high-temperature Badger valve, which was custom-made by Badger using low, dead-voluem 1/16” Valco-Vici connectors. This allowed ILS to construct a system using narrow-bore (0,1mm i.d.) stainless-steel capillaries with a minimum of dead volume. The head is mounted in a custom oven in order to prevent flashing effects and freezing when operating with supercritical media.

Particularly suprising was the robustness exhibited by the valve, which is often exposed to fine zeolitic powders entrained in the adsorbant liquid streams. The valve has never had to be replaced and has been in operation for nearly 3 years now.