MODELLING THE DRAG REDUCING EFFECT OF CO2 CORROSION INHIBITORS

摘要

The drag reducing effect of corrosion inhibitors was measured at a microelectrode array incorporated flush into a surface impinged with a submerged jet. The measurements were performed under mass transport control with the bexacyanoferrate(II)/(IlI) redox system. N-(2-methylenenaphthyl)-quinolinium bromide (MNQB) yielded a drag reducing factor of 0.5 at concentrations of 0.5 mM, and trimethylammonium chlorides with C12.18 chain yield factors of 0.2 above their critical micelle concentration. Critical inhibitor concentrations from electrochemical measurements match very well with results from CO_2 corrosion experiments under flow conditions. The inhibitors decrease the flow fluctuations in turbulent flow. Fourier transformations of roughness profiles of corroded coupons showed that MNQB increases the dimension of near wall eddies, For the prevention of flow induced localized corrosion in CO_2 corrosion systems formulations of inhibitors that prevent metals from pitting corrosion and inhibitors with optimum drag reducing effect at minimum concentrations are needed.