超临界CO2萃取维生素C、联苯二酸、苯甲酸及萘乙酸的相平衡研究

本文用CO₂作为超临界萃取剂，有机溶剂乙醇、丙酮为夹带剂，研究了维生素C、联苯二酸及不含夹带剂时苯甲酸与萘乙酸等固体溶质在超临界萃取剂中的相平衡。实验表明，维生素C、联苯二酸在超临界条件下，无论是含还是不含夹带剂，在超临界CO₂ 中的溶解度均为痕量。在相同的温度、压力下，苯甲酸的溶解度比苯乙酸大很多，理论分析认为，这是由于苯甲酸的极性较萘乙酸的强所致。实验中测定苯甲酸的压力转变为23MPa，萘乙酸的压力转变为12.29MPa。

Phase equilibrium of vitamine C,diphnic acid, benzoic acid and 1-naphthalene-acetic acid in SC CO2

Solubility of vitamine C, diphnic acid, benzoic acid and 1 naphthalene acetic acid in SC CO 2 with and without cosolvent was experimentally determined. The experimental results show that the solubilities of vitamine C and diphnic acid in SC CO 2 are very low with and without cosolvent. It is also shown that the solubility of solids of benzoic acid and 1 naphthalene acetic acid increases with increase in pressure. And the relationship between the solubility of solids and the system temperature was also given in this paper. There is a transform pressure in the solubility of solids in SC CO 2 at which the increasing trend of solubility of solids in SC CO 2 with temperature is transformed and in this paper the transform pressure of benzoic acid and 1 naphthalene acetic acid was measured. Cosolvents play an important role in solubility of solvent in SCF and its action was analyzed too. The hydrogen bonding of polar cosolvent has an important action on the solubility.