鼓气膜吸收法海水提溴研究

STUDY OF AIR-BLOWING MEMBRANE ABSORPTION PROCESS ON EXTRACTION OF BROMINE FROM SEAWATER

以开发高效节能的提溴工艺为目的,设计了鼓气膜吸收法海水提溴过程,压缩空气透过第1级聚偏氟乙烯中空纤维疏水膜,鼓泡进入含溴水溶液,将溴吹脱出来,含溴气体透过第2级膜进入吸收液被吸收;试验考察了各因素对膜吸收提溴性能和传质系数的影响。结果表明,传质系数随吸收液体积、装填密度和鼓气强度的增加而增大,但随温度变化不明显;装填密度15.71%、吸收剂碳酸钠与尿素的量比为3:1时提溴效果最好。鼓气膜吸收法对浓海水提溴有90%以上的脱除率,操作参数优化后,溴的吸收率可达99.6%,回收率可达89%。

Hydrophobic polyvinylidene fluoride （PVDF） hollow fiber membrane was used in novel designed air-blowing membrane absorption （ABMA） process for the extraction of bromine from seawater. The effects of operation conditions, such as the absorbent proportion, the volume and temperature of the absorption solution, the air-blowing intensity, and the packing density of the membrane modules on the mass-transfer coefficient （K） and bromine extraction performance were studied. The results showed that k enhanced as volume, packing density and air-blowing intensity increased. However, the temperature of the absorption solution showed little effect on K. About 90% bromine removal rate from seawater was obtained when the membrane packing density was 15.71% and absorbent proportional distribution was 3：1. The bromine absorptivity reached 99.6% and the reclamation rate got 89% when operated at the optimized conditions.