Experimental Research On The Scrubbing Efficiency Of Marine Exhaust Gas Based On NaOH

As the atmospheric environment polluted by SO₂emission from marine exhaust gasesbecame more and more serious, countries all over the world and international organizationshave made very strict sulfur emission regulations. Now exhaust gas scrubbing desulfurizationis the most promising technology in the control of ship SOx emission. Foreign countries havecarried out extensive researches and successively developed a variety of desulfurizationequipment. However, there is less researches of marine exhaust gas scrubbing technologies.Therefore, the research of reaction mechanism of marine desulfurization equipment satisfyinginternational emission regulations becomes a very urgent task.By the method of combining theoretical analysis and experimental research, this paperstudied on the effect of each factor of exhaust gas desulfurization scrubbing process withNaOH as absorption agent on desulfurization efficiency. The calculation formula ofabsorption liquid desulfurization capacity based on the chemical reaction equibrium principleof liquid phase is derivated, and the desulfurization limit of absorption liquid is determined.By the packed tower experiment, the effect of absorption liquid pH value, liquid-gas ratio（L/G）, SO₂concentration, packing type, packing height, CO₂concentration and absorptionliquid temperature on desulfurization efficiency is researched.Under the condition of this experiment, the results showed that the suitable processparameters for the scrubbing absorption system are absorption liquid pH value of11¹2andliquid gas ratio of3⁴L/m3; the desulfurization efficiency of scrubbing system decreased asthe increase of SO₂concentration, but the drop rate depened on the pH value of absorbingliquid. When pH value of absorption liquid was less than10.3and SO₂concentrationincreased from300ppm to900ppm, the desulfurization efficiency of scrubbingdesulfurization system dropped more than10%. But when the pH value was bigger than11.5,the desulfurization efficiency descended less than5%; the packing type has a great influenceon desulfurization efficiency, and desulfurization effect of Dg16Metal Pall Ring was betterthan Dg16plastic pall ring and Dg25plastic wreath; the increase of packing height canobviously affact the desulfurization efficiency of scrubbing desulfurization system.Desulfurization efficiency of the desulfurization tower with12cm packing is20%more than the desulfurization tower with no packing, and the higher height of packing, the higherdesurfurization efficiency of the system. The influence of various CO₂concentrations ondesulfurization efficiency is little. The effect of absorption temperature on desulfurizationefficiency is relatively big, and the effect increases with the increase of temperature. When theliquid temperature increased from20℃to50℃, the desulfurization efficiency dropped byonly8%, but when the absorption liquid temperature increased more than50℃, thedesulfurization efficiency dropped over20%.This paper carried out theoretical analysis and experimental research on the variousfactors affecting desulfurization efficiency, providing the valuable design reference for furtherdesigning of actual ship closed-loop desulfurization device.