Study On Flue Gas Desulfurization And Dedusting By Emulsion Liquid Membrane

Emulsion liquid membrane(ELM) is a new energy-efficient separation technique and is widely used in environmental protection. In order to develop a new efficient technique for flue gas desulfurization and dedusting, an ELM system with kerosene as solvent, L-113B as surfactant, Ca(OH)2 solution and NaOH solution as internal phase respectively was investigated. The operating conditions of flue gas desulfurization were studied in detail. The results showed that when internal phase was Ca(OH)2 solution, the concentration of L-113B in membrane phase was 2%(v/v), the Ca(OH)2 concentration in internal phase was 0.0216mol/L, the pH of external phase was 9, the volume ratio of oil phase to internal phase was 5:5, the emulsion to external ratio was 1:5. When internal phase was NaOH solution, the concentration of L-113B was 3%(v/v), the NaOH concentration in internal phase was 0.10mol/L, the pH of external phase was 8, volume ratio of oil phase to internal phase was 5:5, emulsion to external ratio was 1:5. Under the optimum conditions, the desulfurizaing efficiency was more than 99.0% for two methods. As the emulsion with kerosene as solvent, L-113B as surfactant has a good stability and very good dispersing ability, it could contact with flue gas better. As a result, the efficiency of desulfurization was increased and the cost was lowered for the desulfurizing agent is reduced.Based on flue gas desulfurization, dedusting by using ELM was studied. The results showed that the dedusting efficiency was higher than 98.0% for these two methods. A good adhering of the emulsion bubble surface made it has a very strong adsorbability to dust in flue gas. Especially, the dedusting effect was much better for tiny dust. Therefore, the ELM system could achieve integration of flue gas desulfurization and dedusting.Furthermore, demulsification of emulsion loaded sulfur and dust was studied by combing the methods of precipitation and high voltage electrostatic. The results showed that the efficiency of demulsification could reach 98.8%. The kerosene and surfactant could be reused. For this method lowered the cost for flue gas desulfurization and dedusting, it accorded to the require of energy-saving and ejection-decreasing.