Optimization Study On Magnesium-base Desulphurization System For Marine Exhaust Gases

In order to enable magnesium-base flue gas desulphurization system to be applicable to marine exhaust gases, an optimization study was carried out based on an established marine exhaust gases scrubber. Through experiment contrasts, the applicative desulphurization method was determined. The desulphurization tower was designed optimally based on the results of literature researches and theoretical computations, and corresponding modifications were carried out. A desulphurization efficiency model of magnesium-base seawater scrubber was created by statistical software. And the reliability of the model was verified. The mechanism of a novel hydration reaction was investigated experimentally. And then a high effective and continuous MgO hydration unit was established. Finally, the applicability of magnesium-base seawater desulphurization system for. marine exhaust gases was test onboard.First of all, a study to compare three desulphurization methods including seawater, magnesium and magnesium-base seawater was carried out. The results show that the magnesium-base seawater method has characteristics of high desulphurization efficiency, limited volume of wastewater and no consumption of fresh water. Therefore, it could be concluded that the magnesium-base seawater method is suitable for marine exhaust gases desulphurization.In order to fulfill the requirement of high effective and low pressure drop, optimizing design and reforming of desulphurization tower were conducted to make it suitable for marine exhaust treatment. After literature researches and theoretical computations, comprehensive optimization of the tower type, gas induced way, spray system and mist elimination system were carried out. A response surface model was created by Minitab15software to predicate the desulphurization efficiency of magnesium-base seawater system. The analysis of variance and experimental test results verified that the model was reliable and could be used to navigate the design space.Traditional MgO hydration system (liquid-solid) has the shortages such as large occupied and low hydration efficiency, which restrict its application in marine scrubber area. Therefore, a novel and high effective hydration method was put forward and the mechanism was investigated. The results of study indicated that the hydration efficiency of gas-liquid-solid reaction system was promoted significantly than liquid-solid system. Within the seawater, the hydration product of gas-liquid-solid reaction system has good fluidity and the impurity was covered by the hydration product, which mean free of clogging.Eventually, the combination of high effective and continuous MgO hydration unit and the modified desulphurization tower constituted the magnesium-base seawater marine exhaust gases desulphurization system. The system was operated under the guide of desulphurization model. The results of continuous test showed that the system has the characteristic of high desulphurization efficiency, low pressure drop, good stability. It could be concluded that the magnesium-base seawater desulphurization system applied to marine exhaust gases treatment.