Flue Gas Desulfurization By Seawater And Brine

With the development of seawater desalination industry, the emissions of brine are steadily on the increase, and the utilization of brine is attentioned by scholars increasingly. In the process of seawater desalination, it will yield a great deal of brine, which there is higher alkaline than seawater. Seawater desulfurization is based on the alkalescence of seawater, therefore it is more potential to exploit flue gas desulfurization(FGD)of brine. flue gas desulfurization by brine will provide a new prospect for coastal areas FGD industry, and will also accelerate the development of the seawater desalination industry. Aim at the blankness of research and application for brine FGD,In this study, we carried out to research and compare desulfurization capacity of seawater, distillation brine and reverse osmosis brine by using a spray scrubber and a packed tower for the first time. Thence, It is great theoretical significance and application value to conducted research in this area.In this study, we carried out to research and compare desulfurization capacity of seawater, distillation brine and reverse osmosis brine by using a spray scrubber and a packed tower for the first time. The paper studied the affect of factors such as absorbent property, flue gas SO₂ concentration, liquid-gas ratio, temperature, flow, packed bed height and so on to the desulfurization performance of seawater and brine respectively. In the experiment, we explored the changes about the temperature, pH value, and concentrations of flue gas desulfurization eluant, and take a recovery experiment for eluant by simulating industrial aeration process. Experimental results showed that both seawater and brine had a good desulfurization effect to the flue gas of low sulfur dioxide, there isn't significant difference between the desulfurization performances at the same experimental conditions. But brine desulfurization efficiency is gradually superior to seawater with the increased concentration of SO₂. Flue gas SO₂ contents, liquid-gas ratio, filling height are significant affect factors for flue gas desulphurization of seawater and brine, while other factors have less influence on the desulfurization rate. The total specific surface of packed tower is a lot larger than that of spray scrubber, and the filler layer is able to promote fluid turbulence, enhancing mass transfer between gas and liquid, so the desulfurization efficiency of packed tower is better than spray scrubber. The temperature of eluant increased slightly, but pH value, concentration, concentration took place large changes comparatively. Eluate should mix with a large amount of absorbers before aeration so that it had sufficient alkalinity to neutralize H+ that generated in the aeration process. The sulfate content was diluted by mixing too, and its increment becomed wee. The pH value and concentration of mixed solution were restored to its original level basically after 20 minutes aeration process, the solution discharged had little impact on the sea environment. The alkalinity of brine is about 2 times of seawater, therefore, it able to achive the same aeration effect while the mixed usage of brine is half of seawater in the aeration tank, it reduce the area of aeration tank and the cost of drainage post-processing to a certian extent. The results of the experiment will be very significant to direct the desulfurization of seawater and brine.