When demulsifier solves one problem and cooks your exchanger

In our condensate stabilizer train, every time ops bumped the demulsifier, our E-205 shell-and-tube went from clean to molasses in a week. We chased velocity, baffle leakage, metallurgy, even blamed crude blend. Turned out the fix was polymerizing in hot zones and plating the tubes.

We rigged a cheap side-stream with a 40 µm strainer and a beaker-on-a-hot-plate test at process film temps to see if the dose browned. Moved the injection lance downstream of the hot bundle, cut rate 30%, and used DP across the coalescer as the feedback, not just water cut. Fouling interval went from 7 days to 9 months.

I can tweak turbulence and tube counts all day, but I need a fast way to flag a sticky chemical before it cooks on steel. What quick field screens do you trust? Hot-wall coupons, quartz crystal microbalance, stirred bomb, something I can run on site? I’m not wiring a cloud skid or waiting six weeks on a lab. What’s your go-to, field-grade and repeatable?