Research Of Anticorrosive Coatings In Flue Gas Desulfurization

In the Flue Gas Desulfurization (FGD), it is a problem that equipments are corraded in heat temperature, and terribly abrased by soot. However, there is not any coating effectively solving the problem. According to diffenert corrosive condition, we developed two anticorrosive coatings.One is glass fiber vinyl ester resins coatings, the other is Novolac-Epoxy Vinyl Ester Resins anticorrosive system: consists of mortar and top coat. They both include film-forming substance composed of Novolac-Epoxy Vinyl Ester Resins (NE-VE) and curing system of methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate (CoOCT). They are both two-component and high paints and can be cured on the normal temperature.We focused on the relationship among film-forming substance, curing agents, category and granularity of glass fiber, coupling agents, contentss of glass fiber, and the properties of top coatings. The result of the experiments shows that the coatings is film-forming substance composed of Novolac-Epoxy Vinyl Ester Resins (NE-VE), contains C type glass fiber dealing with coupling agents, and proper contents of glass fiber. This paper explored EIS and mechanical test to reach the optimum contents. It is discussed that the best corrosion and penetrability resistance was observed when the rate between glass fiber and resins in the range of30/100. After120days of the coating’s immersion in a3.5%NaCl solution, the polarization resistance kept higher than109O·cm2, improved as a hundred times as the normal one.To solve terrible corrosive position in FGD, such as flue between heat exchanger and absorption tower, we designed anticorrosive system, consisting of mortar and top coat.This paper explored heat-resistance test and SEM and TG test to reach the result that the surface of coat is compactible in temperature of120℃and well mechanic performance. After heat7hours in120℃, the coatings were tested in a3.5%NaCl solution by EIS.The result showed that the polarization resistance kept higher than10O-cm, it proved that heat resistance and best corrosion and penetrability resistance were observed. When Novolac-Epoxy Vinyl Ester Resins mortar and top coat use toghter, more effectivity was reached.In short, the tow anticorrosive-coatings developed were well mechanic performance and heat resistance and best corrosion and penetrability resistance. It provides effective project to solve anticorrosion in FGD.