What’s the value in testing for MEA-triazine manufacturing? How much does a few thousand gallons of ethanolamine and formaldehyde cost? And, if you mix wrong, the chemical cost is the least of your problems. How much will the lost business cost once your customers figure it out?
We received five MEA-triazine samples from a reputable, high-quality, high-volume chemical manufacturer. Based on history, we expected all five samples to be around 80% triazine concentration by-weight. All five were very viscous, as expected for this type of sample. But all five are also various shades of yellow, even though their manufacturing dates are within the past few months. Normally, we would expect a freshly manufactured triazine blend to be water clear to slightly yellow. Although we rarely use color as an indicator of a problem, in this case, they called us, so something must be wrong.
We analyzed the first bottle: >70% triazine. Encouraging. Since pipetting accuracy is questionable with viscous samples, we did a 1-1 dilution (by mass) in water. Re-analyzed, the result is 38%, so a 76% triazine blend with a couple percent excess MEA. Very nice.
We proceeded to dilute the remaining samples with the expectation that they would all be >70% triazine. Second sample: Low 30% range with a large amount of excess monoethanolamine. That’s strange. So, we remeasured without dilution: 57% triazine with 15% excess MEA. The remaining three samples were all similar, between 55-60% triazine with 15-20% excess MEA.
Can we fix it?
To understand these samples a little bit more, we took one that was 56% triazine and 16% excess MEA. We weighed out 1 gram of sample, added 64 mg of paraformaldehyde, and vortexed aggressively. The paraformaldehyde suspended in the triazine without reacting — it needs a little base to dissolve. We added 450mg of 1M NaOH and mixed again. The solution turned clear and warm. Success!
When tested, this new sample was 49% triazine with 2% excess MEA. Running through the numbers above, we would expect 47% triazine with 2% excess MEA — very close to the measured results. It’s great when the math works out.
|Start (mg)||Reaction (mg)||End (mg)||End (%)|
Theoretically, MEA-triazine manufacturing is easy. It’s just three molecules of monoethanolamine and three molecules of formaldehyde. But the devil’s in the details: What’s the MEA quality? What’s the formaldehyde concentration? Did you paraformaldehyde dissolve properly? Are there stabilizers in your formalin? Did you maintain the right temperature for the reaction to proceed quickly while avoiding product damage?
Measure before your customers do
If you get any of these wrong, your customers will let you know — possibly. They might never know the concentration was wrong (although more and more are testing with an OPAL-103), but they will eventually figure out it performs poorly. Best case, they tell you. More likely, they quit buying from you.