关键词: 柠檬酸, 萃取法, 分离, 提取

Abstract: Citric acid is an important organic acid and one of the largest amounts of fermentation products in the world. In the paper，it is comprehensively synopsized for the principles，advantages and disadvantages about the liquid-liquid extraction and liquid membrane extraction. The current development of two systems and problems need to be solved now are discussed in detail. They have little pollution，high extraction efficiency and low cost，but they are all easy to emulsify due to emulsifiers，proteins，polysaccharides contained in fermentation broth，meanwhile liquid membrane extraction method is complicated. Based on these shortages，ionic liquid applied to the citric acid extraction system is proposed. And the idea ensures the extraction keep its advantages，but also overcome its emulsification，while ion liquid can be recycled，which will increase its energy-efficiency，and reduce the cost of separation.

Key words: citric acid, extraction method, separation, extraction