Corrosion inhibition in pipelines by drag reducing polymers

Abstract

To investigate the possibility of using drag reducing polymers as corrosion inhibitors in situations where the rate of corrosion is controlled by the rate of depolarizer diffusion to cathodic sites, the effect of Polyox WSR–301 on the rate of cathodic reduction of K₃Fe(CN)₆ at a pipe wall was determined by measuring the limiting current. The variables studied were flowrate and polymer concentration. Polyox was found to decrease the rate of depolarizer reduction at the cathode by an amount ranging from 12 to 42%, depending on the Reynolds number Re. The percentage decrease in the rate of depolarizer reduction α was found to be insensitive to polymer concentration and to be related to Re by the equation α = a Re^0–5, where a is an experimental constant.