Development of an electrochemically integrated SR-GIXRD flow cell to study FeCO3 formation kinetics

An electrochemically integrated Synchrotron Radiation-Grazing IncidenceX-Ray Diffraction (SR-GIXRD) flow cell for studyingcorrosion product formation oncarbon steel incarbon dioxide (CO2)-containing brines typical of oil and gas production has been developed. The system is capable of generating flow velocities of up to 2 m/s at temperatures in excess of 80  °C during SR-GIXRDmeasurements of the steel surface, enabling flow to be maintained over the course of the experiment whilediffraction patterns are being collected. The design of the flow cell is presented, along withelectrochemical anddiffraction pattern transients collected from an initial experiment which examined the precipitation of FeCO3 onto X65carbon steel in a CO2-saturated 3.5 wt. % NaCl brine at 80  °C and 0.1 m/s. The flow cell is used to follow thenucleation andgrowth kinetics of FeCO3 using SR-GIXRD linked to the simultaneouselectrochemical response of the steel surface which were collected in the form of linear polarisation resistancemeasurements to decipherin situcorrosion rates. The results show that FeCO3nucleation could be detected consistently and well before its inhibitive effect on the generalcorrosion rate of the system.In situmeasurements are compared withex situscanning electron microscopy(SEM) observations showing the development of an FeCO3 layer on the corroding steel surface over time confirming thein situ interpretations. The results presented demonstrate that under the specific conditio...

Source: Review of Scientific Instruments - October 28, 2016 Category: Physics Authors: D. Burkle, R. De Motte, W. Taleb, A. Kleppe, T. Comyn, S. M. Vargas, A. Neville and R. Barker Source Type: research