Feasibility Testing and Samples

Obtaining Samples

Most DOWEX™ ion exchange resins, polymeric adsorbents, chelating resins, and copolymers may be purchased from laboratory supply houses in a variety of sample sizes. To request sample availability and pricing, please visit the ion exchange sample request page.

If you find that the resin of interest is not available from the ion exchange sample request page, or if the quantity you need is not listed, contact us for information on how to obtain a sample.

Processing Organic Solvents
Tips on how to dry ion exchange resins and adsorbents for evaluation in organic solvent systems.

Feasibility Testing

In order to carry out feasibility testing, a good understanding of how the chemical separation process works is helpful.

A separation process consists of two components: 1) the chemistry of the separation and 2) the engineering of the separation. The chemical component is the affinity that the resin has for the target molecule. The engineering component consists of the bed dimensions, flow rates and other engineering parameters of the process.

People often jump to a column test where they may run the experiment under engineering conditions that are inconsistent with the limitations of the chemistry. Therefore it is a good idea to first evaluate the chemistry of the separation under equilibrium conditions before the engineering experiment is performed. Equilibrium isotherms enable you to compare the performance of many different resins for a given separation. They also allow you to explore optimal regeneration conditions. Because some operations are performed in batches, an equilibrium isotherm test acts as a miniature simulation of this process.

Notice: While we have provided information on resin selection for a variety of separations in good faith, process streams are often more complicated than they appear. The presence of other components or conditions can complicate a separation or operation. Therefore, Dow strongly encourages customers to evaluate these separation media on the exact process stream of interest.


Performing Equilibrium Tests
Details on how to perform equilibrium isotherm tests and an example of an equilibrium isotherm test are available as downloadable (printable) literature.

Equilibrium Isotherm Testing (23KB PDF)


Column Separation Evaluation
Most ion exchange and adsorption processes are carried out in columns in order to take advantage of the multiple equilibrium steps created by this operation. Once you complete an equilibrium isotherm evaluation and choose candidate resins for further testing, a laboratory column evaluation is performed to further pinpoint the resin of choice and determine optimal operational parameters for scale-up and operation. The results of column evaluations will provide the necessary information to calculate the capital cost of a separation and operational cost of separation media. You may also be able to calculate life expectancy of the media.

Details on how to perform laboratory column tests are available as downloadable (printable) literature.


Laboratory Guide, Column Testing (170KB PDF)



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