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Innovative Water Treatment Chemistry with Matheus Paschoalino
Episode 438
Can a carbon-negative, bio-based molecule replace legacy phosphonates and help you use less azole—without sacrificing corrosion performance? In this episode, host Trace Blackmore, CWT, welcomes Matheus Paschoalino, PhD Senior Business Development Manager and Microbial Control SME of Solugen, to unpack polyhydroxycarboxylic acids (PHCs) and how they’re changing cooling-water programs from the field up. We cover HEDP replacement in light-duty systems, azole enhancement in copper-challenged waters, a second-generation cut for heavy-duty heat flux, and PHC behavior with oxidizers and non-oxidizer biocides.
From Bioforge to Basin: How PHCs Are Made and Why It Matters
Paschoalino explains Solugen’s chemo-enzymatic “Bioforge” approach that oxidizes sugars (corn-syrup feedstock) into PHCs with very high yield and no practical byproducts—a pathway validated as carbon-negative. He outlines how different “cuts” (monoacid-rich vs. diacid-rich) map to different use cases, and notes current manufacturing capacity and adoption across hundreds of towers.
Replacing HEDP in Light-Duty Programs
For hospitals, HVAC, and other light-duty systems, PHCs have fully replaced HEDP as the anodic corrosion inhibitor while keeping PBTC for scale, enabling lower total phosphorus formulations with equal or better performance compared to status-quo organics.
Azole Enhancement, Free Copper, and Real-World Cost
Field work showed PHCs chelate metals quickly, protecting azole demand when free copper is present (e.g., after oxidizer flushing) and reducing expensive azole overdosing. One university case dropped an adjunct 8-ppm azole feed by pairing the base 3–4 ppm azole with PHC, yielding both corrosion control and lower discharge costs.
Second-Generation PHCs for Heavy-Duty Heat Flux (Toward “Neutral Phosphorus”)
At higher heat flux and stabilized-phosphate conditions, a diacid-rich second-generation PHC proved more stable, enabling orthophosphate reduction and opening a path toward “neutral phosphorus” programs that leverage background phosphate in municipal make-up. Bench data also show synergy with trace metals (e.g., zinc).
Biocide Potentiation and Where It Works Best
PHCs remain stable with oxidizers like chlorine dioxide and bleach. Their most compelling synergy shows up with non-oxidizers and peracetic acid (PAA): as a biocide potentiator, PHCs can reduce the need to overdose actives such as THPS, glutaraldehyde, quats, and DBNPA by first complexing interfering metals (e.g., Fe/FeS), letting the biocide perform as intended.
Not “Bug Food”: Pilot Cooling Towers and Oxidizer Demand
To address the industry’s biggest concern with bio-based chemistries, Solugen ran side-by-side outdoor pilot cooling towers under identical bleach control. Result: comparable oxidizer usage and consistently low counts versus HEDP—evidence that PHCs don’t fuel biofilm.
Chelation Mechanics, Polymer Savings, and White Rust
PHCs chelate beyond acid-group stoichiometry thanks to multiple hydroxyls and conformational effects—critical for controlling dissolved metals and protecting films. In stressed heat-flux/chlorine conditions, PHCs reduced calcium-phosphate fouling versus HEDP, often allowing polymer dosage cuts. Early data also show promise for white-rust mitigation on galvanized systems, with the diacid-rich
Published on 1 week ago