Views:58 Author:Ronsco Publish Time: 2021-08-12 Origin:Ronsco
The 3rd International Summit on the Application of Marine Scrubber and Ballast Water System and the 2nd International Summit on LNG Powered Ships and LNG Technical Equipment were successfully held in Shanghai.
Dr. Quanming Song, China Chief Representative of the Nickel Institute, was invited to attend and deliver a keynote speech entitled "Selection and Manufacturing of Marine Scrubber Alloys". Dr. Song first introduced the core work and service objectives of the International Nickel Institute to the delegates. Then he mentioned that with the changes in relevant environmental regulations issued by the International Maritime Organization (IMO), the current upper limit of sulfur content in ship exhaust gas has been reduced from 3.50% (weight ratio) to 0.50% (weight ratio), aiming to further reduce the amount of ship exhaust gas. Sulfur oxide emissions. This regulation will take effect on January 1, 2020. This regulation indicates that the demand for nickel-containing materials in the marine desulfurization industry will increase substantially.
As a non-profit organization, the International Nickel Institute is very concerned about this industry, not only because its members are large mining companies, and their products need to be transported by sea; more importantly, almost all marine scrubbers involve special materials, especially double The use of phase steel, super austenitic and nickel-based alloys. As an industry association with a long history, the International Nickel Institute has more than 40 years of technical experience in the desulfurization industry, and has also carried out nearly 20 years of research in the field of marine scrubbers.
Dr. Song mentioned that although there are other solutions to reduce the sulfur content of ship exhaust gas in addition to scrubbers, considering all factors, marine scrubbers are still the most applicable technical means. Then introduced the types of marine scrubbers, including open-loop, closed-loop and hybrid. The open-loop scrubber uses the natural alkalinity of seawater for neutralization; the closed-loop scrubber requires the addition of alkaline solution (such as sodium hydroxide, etc.) for neutralization; and the hybrid type combines the two in many situations As a hybrid system, the most appropriate technology is adopted according to the marine environment. Regardless of the method, because the internal high temperature and corrosive environment of the scrubber are very harsh, it is necessary to use nickel-containing materials with extremely high corrosion resistance, such as 2205 duplex stainless steel, 254 super austenitic and nickel-based alloys. Therefore, the correct selection of materials is the key to the failure of the scrubber. Among the factors that affect the selection of materials, we need to be concerned about the corrosive environment. The main factors include temperature, pH, and chloride ion content. Usually under high temperature seawater conditions, according to the specific circumstances, we will recommend the use of nickel alloys such as super austenite (example 254) on dual-phase steel.
In the next report, Dr. Song introduced the types of alloys that should be selected according to different working conditions and different corrosive environments. In particular, the corrosion of marine scrubbers is often not uniform corrosion, but local corrosion such as pitting and crevice corrosion. In addition to the selection of materials, the welding process and standards are also critical for corrosion resistance.
Finally, Dr. Song concluded that in view of the lack of experience accumulated in the current market and the expected life expectancy is not yet known, it is recommended that when selecting materials, you should consult relevant materials research units on the premise of fully understanding the working conditions, and avoid simply selecting materials from an economic point of view. Can not achieve the effect of long-term use, and even bring more serious consequences. As an industry association with a long history, the International Nickel Institute has been committed to supporting the development of the desulfurization industry at home and abroad for many years, and has built a “technical support” platform for free sharing worldwide. It hopes to establish long-term cooperation with the domestic marine desulfurization industry and contribute to the development of the industry. Make positive contributions.