Studies On Renewable Amine Method Desulfurization Process

With the rapid economic development, china's air pollution isincreasingly serious, especially SO2pollution. It's not only brings harm to theecological environment and human health, but also caused huge to economiclosses. At the same time, there is a serious problem of shortage of sulfurresources. Organic amine flue gas desulfurization technology has thefollowing advantages: high desulfurization efficiency, absorbent can berecycled, SO2can be recyclable used, no secondary pollution. So this methodhas broad application prospects.The absorption system of screening experiments was carried out in aself-made bubble reactor. By comparing absorption efficiency and the changesof the absorbent's pH value, we selected the ethylenediamine/phosphoric acidabsorption system.In order to determine the desulfurization process conditions, we usedethylenediamine/phosphoric acid solution as the absorption system and carried out experiments in the packed column, which diameter is38mm and the heightis1m. We investigated the impacts of ethylenediamine concentration, liquid togas ratio, the initial pH value of the absorption solution, the initialconcentration of SO₂and the reaction temperature on desulfurizationefficiency. The appropriate process parameters were as follows:ethylenediamine's concentration was0.3mol/L, liquid to gas ratio was0.8L/m3, the initial pH value of the absorption solution was7.15, absorptiontemperature was50.The desorption process conditions of the ethylenediamine/phosphoricacid system was studied. We investigated the impacts of desorption time,reaction temperature, the initial pH value of the loaded solution, theethylenediamine's concentration and the surfactant on desorption efficiency.Experimental results show that desorption efficiency was increased with theextension of desorption time and the increased reaction temperature. Thedesorption efficiency was decreased with the increased of the ethylenediamineconcentration and the increased initial pH value of the loaded solution. Whenheated60min, the solution added SDBS's desorption efficiency raised from37.55%to45.85%, and after added K12to the solution it's desorptionefficiency raised from37.55%to59.99%.In order to investigate the desulfurization performance of the renewableethylenediamine/phosphoric acid system, we carried out the cycle experiment.The experimental results show that with the repeated use of the absorbent, the absorption efficiency was declined and the desorption efficiency wasincreased. When added K12to the solution, the absorption and desorption ofSO₂can be promoted.On the basis of the experimental sudies we deduced the expression ofthe volumetric overall mass transfer coefficients. We investigated the impactsof ethylenediamine's concentration, liquid to gas ratio, the initial pH value ofthe absorption solution, the initial concentration of SO₂and the reactiontemperature on KGa. The experimental results show that KGa could beimproved by increasing the ratio of liquid to gas, the concentration ofethylenediamine and the initial pH value of the absorption solution. KGadecreased with the increased of the initial concentration of SO₂and theincreased reaction temperature.