Keizo Hosoya

Corrosivity of Br- and Cl- on duplex stainless steel

Abstract This report discusses the basis for material selection in chemical plants, especially focusing on the design of an actual plant based on laboratory corrosion test results. Both the chemical system created when chlorine gas and bromine gas were neutralized with alkaline solution, and material economics are considered when selecting duplex stainless steel as a construction material. In addition, the corrosivity of Br − and Cl − with or without BrO − and ClO − on duplex stainless steel is discussed in terms of pitting and crevice corrosion. Br − ions show a lower tendency to promote pitting and crevice corrosion on duplex stainless steel, compared with Cl − ions. BrO − , existing in a bromine gas neutralization system, acts as a strong oxidizer and easily shifts the corrosion potential of duplex stainless steel more noble, drastically promoting crevice corrosion.

Material Problems in Amine Processes for CO2 Recovery

CO2 recovery has been widely discussed to be one of the key issue to prevent green house effect. On the base of present technology, amine processes like MEA are considered to be feasible for the application on CO2 recovery from power plant flue gas. Amine process have been widely applied in petroleum refinery, and much attention has been paid to obtain the reliability of amine plant in terms of IGSCC of carbon steel weld. The case study of IGSCC on carbon steel in the existing amine processes and the effect of the types of treated gas on IGSCC in MEA solution are discussed.