Evaluation of Green Scaling Inhibitors by Thermodynamic Rate-Modeling

Activity: Talk or presentationTalk at conference or symposiumScience to science


Green technologies are on the rise and not stopping at the gate of tunnel construction sites. So called “green inhibitors” (GI) are eco-friendly, biodegradable organic molecules, which are already applied in many technical fields (oil/gas-industry, industrial and potable water treatment, …) for scaling reduction (mainly CaCO3 precipitation) and increasingly used in drainage systems of motor- and railway tunnels. Although, GI’s are known to significantly decrease mineral precipitation out of an aqueous solution, their individual inhibition effects are less explored. Therefore, we investigated the functionality and efficiency of aspartic, maleic and acrylic GI products at dosages from 0.5 to 10 mg L-1, using a newly developed rapid and compact test procedure. The GI performance is quantified by combining existing thermodynamic rate models for CO2-flux and CaCO3-precipitation. The results showed that (i) the GI performance is independent of the CO2 degassing rates, (ii) the supersaturation of calcite reaches an upper limit approaching the solubility of amorphous calcium carbonate, and (iii) average efficiencies of 70% up to 100%, and (iv) a delay of crystal nucleation of 3 to 6 times – compared to the control test (no inhibitor) – are observed. Our results also reveal new insights into preferential CaCO3 polymorph formation: aspartate is suggested to modulate calcite crystallites by serving as a template for predominant vaterite growth. The rate-model aided test procedure provides a compact and rapid tool to assess and quantify GI performances against CaCO3-scaling to be properly selected and individually tuned.
Period20 Sep 2021
Event titleMinPet 2021
Event typeConference
Degree of RecognitionNational