Novel Surface Treatment to Mitigate Fouling in Heat Exchangers and Process Equipment

Abstract

The global impact of climate changes due to greenhouse gas emissions cannot be overemphasized. To combat this, engineers are striving to develop innovative enhancements for heat transfer and fouling reduction in process equipment as a pathway to reduce CO2 emissions. A novel surface application of Minimox® treatment, a water-based suspension of rare-earth oxides, is a promising solution. The self-protective alloy treatment, unlike a traditional continuous coating, has no measurable thickness, does not impose any operating temperature limits, protects from high temperature oxidation, and decreases surface energy and polarity that leads to low fouling and coking rates. Minimox can be applied by dipping or spraying to both external and internal surfaces, including non-conventional tubing shapes. A post-application curing at 400 °C for 1 h is needed to ensure maximum fouling mitigation efficacy. Laboratory tests conducted to simulate operating conditions in a Coker furnace show that the Minimox-treated tubes reduce coke formation by about 80% as compared to untreated tubes. In addition, adhesion of coke to the Minimox treated tubes was significantly lower than for the untreated tubes. Field data collected in refinery applications involving Coker furnace tubes and a vacuum column wash bed are promising, lending support the laboratory results.