Search
Filters
Close

Save 20% on select best sellers with code MONSTER24Shop The Sale Now

Impact of O2 Content on Corrosion Behavior of X65 Mild Steel in Gaseous, Liquid and Supercritical CO2 environments

CO2 stream in CCS system usually contains impurities, such as water, O2, SO2, NO2, H2S, and other trace substances, which could pose a threat to internal corrosion and integrity of CO2 transportation pipelines. The general and localized corrosion behavior of API 5L X65 mild steel were evaluated using an autoclave both in water-saturated CO2 and CO2-saturated water environments in the presence of varying concentrations of O2. Experiments were performed at 25 °C and 35 °C, 8 MPa and 35 °C, 4 MPa to simulate the conditions encountered during dense, supercritical and gaseous CO2 transport. General corrosion rates were obtained by weight-loss method. The surface morphology of the coupons was examined by scanning electron microscopy (SEM). Results indicated that general corrosion rates at each O2 concentration in CO2-saturated water environment were much higher than those in water-saturated CO2 environment. The corrosion rates did not increase with increasing O2 concentration from 0 to 2000 ppm; instead the corrosion rate reached a maximum with 1000 ppm O2 at 25 °C, 8 MPa and 50 ppm O2 at 35 °C, 8 MPa in water-saturated CO2 environment and 50 ppm at 25 °C, 8 MPa and 100 ppm at 35 °C, 8 MPa in CO2-saturated water environment. However, the change trend of general corrosion rate with O2 content at 35 °C, 4 MPa was different from that in 25 °C and 35 °C, 8 MPa both in water-saturated CO2 and CO2-saturated water environments. Localized corrosion or general corrosion rate of over 0.1 mm/y was identified at each test condition both in a water-saturated CO2 and CO2-saturated water environments. When O2 was added, coupon surfaces were covered by a more porous corrosion product scale. A final series of tests conducted with the addition of 100 ppm and 2000 ppm O2 in CO2 environment with 60% relative humidity (RH) and 80% RH revealed that no localized corrosion was observed and the general corrosion rates were lower than 0.1 mm/y at 25 °C and 35 °C, 8 

Product Number: 51320-14433-SG
Author: Xiu Jiang, Dingrong Qu , Xiaoliang Song
Publication Date: 2020
$0.00
$20.00
$20.00
Product tags
Also Purchased