Solving Resin Breakup at a Glycolic Acid Plant

A chemical production facility in West Virginia was using Purolite® A847 acrylic weak base anion resin to remove sulfuric and hydrochloric acid from glycolic acid. The plant was replacing the resin every 3-4 months due to severe resin break up. The pressure drop and downtime due to resin breakup was limiting their production capacity and they asked Purolite to help to solve the problem.

The plant had looked at process variables such as temperature, oxygen content in the feed, fluid distribution and excessive shrink/swell. Purolite visited the site, surveyed the system, and sampled the resin several times during the short lifetime to understand how rapidly the breakup was occurring. 

While Purolite knew the glycolic acid causes severe swelling during exhaustion, the most severe stress occurs during regeneration of the weak base anion where it goes from the hydrophilic exhausted form to the hydrophobic free base form.  It was surmised that the stress at the hydrophobic/hydrophilic interface was the source of the breakup.  The solution then seemed to be to reduce the stress during regeneration by diluting the caustic concentration.

Tests were done using glycolic acid swelling and a lower concentration of sodium hydroxide (NaOH) for regeneration.  A dramatic reduction in broken beads occurred in the lab due to lowering the NaOH dosage.  Upon implementation of new regeneration procedures, the resin life increased from 3-4 months to 2 years.  Additionally, it was noted that operating capacity increased.

Due to the high resin capacity, the plant was able to resume more effective production operations and Purolite’s innovative regeneration technology has now been applied to other industries. No matter how challenging the issue, Purolite is always available to provide technical support and expertise.