Improved process of extracting rotenone from cube root or derris root

摘要

708,735. Solvent extraction of rotenone. KAGEYAMA, I., YASAUMURA, J., and SATO, M. June 25 1951, No. 15048/51. Class 81(1) A cyclic process of extracting rotenone from cube root or derris root comprises treating said materials with monofluoro dichloromethane CH Cl2F, which is liquefied either by compression, by cooling or by simultaneous compression and cooling, bringing the liquid solvent so formed into contact with the root and dissolving out and extracting the rotenone therefrom, vaporizing the solvent to separate it from the extract by decreasing the pressure or by heating or by simultaneously heating and decompressing, repeating the cycle until the extraction is complete and removing the extracted rotenone. As shown, an extraction vessel 2 is connnected by means of suitable pipes and valves to a condenser 11, an evaporator 13 and a solvent tank 18. A cotton bag 1 containing the powdered root'is placed in the extraction vessel 2. The extraction vessel, condenser and evaporator are evacuated through valve 3. Solvent is allowed to pass from the tank 18 to the evaporator 13, where it is vaporized by the hot water or steam passing through pipe 14, and is then condensed' in the vessel 11 by the cold water circulating through pipe 12. The condensed solvent passes into the extraction vessel 3 and the extract siphons through 19 into the evaporator 13, where, the solvent is removed. The cycle is repeated until the root is exhausted when the solvent in the evaporator is passed to the solvent tank 18 by means of a compressor 17. Air is then introduced into the evaporator and the extract run off at 15.