【摘要】 <正>前文曾指出应用连续溶剂萃取法从麻黄草浸渍液提取麻黄素,可以有利地代替目前国内襲用的蒸馏法;并初步认为甲苯、二甲苯及氯苯可能是良好的工业溶剂;因此,测定了麻黄碱在这些溶剂与水溶液之间的分配关系。从所得结果而论,三种溶剂对麻黄碱都具有很高的选择性,可以有效地从麻黄草浸渍液中萃取麻黄碱;用过的溶剂,又可用盐酸更多还原

【Abstract】 Extraction of ephedrine from Ephedra Sinica Stapf leach liquor by three organic solvents was studied in an experimental column of 100 mm. diameter packed with 19 mm stoneware Raschig rings. When toluene was used as the dispersed phase, the mass transfer coefficient Koca obtained at 40° was much greater than that at 20°, whereas the difference between Koca obtained at 60° and at 40° was much less pronounced. The values of Koca can be correlated by the following expressions:at 40? --- = 9’? + 3.0xlO-2 Koea Vc Vdat 60? --!- = -^j- + 2.0x10-3 K0ca Vc VdWhen mixed xylenes were used, the mass transfer coefficient was somewhat smaller than that for toluene, e.g., at Vc ? Vd ?< 15 m3/(m2) (hr), K0ca for toluene was 5% higher than that for xylenes. The maximum throughputs were nearly the same in both cases.Although chlorobenzene has a distribution coefficient almost as high as mixed xylenes and much higher than toluene, it is far inferior to the latter two due to very small mags transfer coefficient, very low throughput andliability of forming permanent emulsion with the crude leach liquor.The application of pulsation in the present case resulted only limited improvement in mass transfer process. With amplitudes of 5 ~ 7 mm. and frequencies of 240 ~ 370 cycles/min., the reduction of (H.T.U.)OC was about 20~35%.The leach liquor with 0.5% of suspended solid matter could be successfully treated in the packed column without any trouble under prolonged or intermittent extractions. According to Pratt[2] packed column cannot handle any liquid containing more than 0.1% of solid, this view may be worth reconsidering if the solid is highly dispersed and does not settle readily.The data of re-extraction of alkaloids from organic solvents by hydrochloric acid were treated according to Sherwood’s method[12] for gas absorption with rapid second- order irreversible chemical reaction, and so far as there was some appreciable free acid present in the aqueous phase the mass transfer coefficient was independent of the acid concentration. The following correlations were obtained:(1) Packed column with acid as continuous phase and toluene dispersed, (2) Spray column with acid as continuous phase and toluene dispersed, (3) Spray column with acid as continuous phase and mixed xylenes dispersed, Vw = 2.27 m3/(m2) (hr),A new flow diagram for the extraction plant was proposed.更多还原