金属微孔膜在甲醇制烯烃(MTO)急冷水过滤中的试验研究

Experimental research of metal microporous membranes in filtration of methanol to olefins(MTO) chilled water

采用过滤精度为1μm的金属粉末微孔膜和金属丝网微孔膜作为过滤净化的核心组件进行甲醇制烯烃（MTO）急冷水的过滤试验,分析了过滤前后急冷水中固体颗粒浓度的变化,过滤过程中过滤器压差、流量的变化以及滤芯失效的原因。结果表明,金属粉末微孔膜和金属丝网微孔膜均能将急冷水中的固体颗粒浓度降低至5 mg/m3以下,相对于金属粉末微孔膜,金属丝网微孔膜过滤MTO急冷水时,其压差更小、流量更大且反吹再生效果更好;金属粉末微孔膜滤芯失效的原因是滤芯表面粘结了100~200μm的团聚颗粒,这些团聚颗粒由1~2μm的固体催化剂颗粒被急冷水中的油脂包裹形成;采用丁酮清洗与高压氮气吹扫的再生方法能有效去除粘结在金属粉末微孔膜滤芯表面的团聚颗粒,滤芯的相对透气系数恢复至过滤前的77.7%。

Metal powder microporous membrane and wire mesh microporous membrane with filtration accuracy of 1 μm were used as the core filter element in filtration of methanol to olefins（MTO）chilled water for experimental research. The change of dust concentration in chilled water,pressure difference and flow of filter during the filtration,failure cause of filter element were studied. The results show that metal powder microporous membrane and wire mesh microporous membrane can both reduce the dust concentration of chilled water below 5 mg/m^3. The pressure difference is smaller,the flow is bigger during the filtration and the effect of regeneration is better when the wire mesh microporous membrane is used as the filter element relative to metal powder microporous membrane. The failure cause of the metal powder microporous membrane is aggregates（100-200 μm）bond on the surface of filter element,which is constituted of catalyst particles（1-2 μm）that wrapped in and bond together by grease in chilled water. The aggregates can be removed by the regeneration method of butanone cleaning and high pressure nitrogen purging,the relative permeability coefficient is restored to 77.7% of that before filtration.