Description:
<jats:p>The transportation of natural gas in long subsea pipelines is a challenge when it comes to hydrate prevention, corrosion and mineral scaling. When monoethylene glycol (MEG) is injected into carbon steel pipelines to prevent formation of gas hydrates, the solubility of the corrosion products is altered. Understanding the kinetics of FeCO<jats:sub>3</jats:sub> precipitation may make it possible to avoid deposition in the gas liquid separation process and improve solids removal in MEG recovery units. In this work, the growth kinetics of iron carbonate (siderite) has been studied in seeded batch experiments in MEG‐water solutions with 0 and 40 wt% MEG at 50 and 70 °C. Precautions were taken to keep anaerobic conditions and avoid oxidation of ferrous ions. The growth rate (G) was measured as function of supersaturation (S) and fitted to the equation: G = k<jats:sub>r</jats:sub>(S‐1)<jats:italic><jats:sup>g</jats:sup></jats:italic>. The growth order (<jats:italic>g</jats:italic>) was approximately 2 independent of the MEG concentration at the two temperatures. The growth rate constant (k<jats:sub>r</jats:sub>) was in the range of 6 × 10<jats:sup>−11</jats:sup> to 1 × 10<jats:sup>−10</jats:sup> m/s. Temperature increase from 50 to 70°C had no measurable effect on the growth rate while in the presence of 40 wt% MEG the growth rate constant decreased.</jats:p>