【作者】 王奇；

【导师】 张婕； 王景涛；

【作者基本信息】 郑州大学 ， 化学工艺， 2021， 硕士

【摘要】 近年来,随着社会经济的快速发展,全球对于聚乙烯产品的需求和消耗在大幅度增长。如何在环境友好的情况下,节能高效地对聚乙烯产品进行后续处理是^一个重大问题,这个问题的有效解决将对石油石化行业的发展和繁荣产生深远的影响和巨大的意义。膜分_离技_术作为新型_的分_离技术,具有_高效、节能、环保、操_作简便等突_出优_点,成为解决社会经济可持续发展难题_的有效途径之^一。二维层状膜_因其有序_的层叠结构、_易于调控_的化学微环境、高效_的分子传递特性_以及_易于超薄化_制膜等特_点成为_了新_型纳滤膜_的研_究热_点。本论文_以高性能二维层状复合膜_的精准制备_以及该复合膜在淤浆聚乙烯脱蜡工业_中的应_用为主要研_究内容,_自主开发_了^一种超薄且稳定_的氧化石墨烯_GO和聚乙烯亚胺_{（P E I）}有机-无机层状复合膜,并且尝试将其应_用于淤浆聚乙_烯脱蜡_的工业应_用中。采用静_电雾化技术开发_的GO-_PEI层状复合膜在具有高纳滤_{性能的同时}能够保持较为优_异的结构稳定性和长_时操_作稳定性,从^一定程度上解决_了传统纳滤膜存在_的渗透通量和截_留率之_间的Trade-_of效应。此外,_将开发_的G_O-_{P E I}层状复合膜尝试应_用于淤浆_聚乙烯脱蜡工业_中的己烷脱蜡工艺,在保持较高_的石蜡分子_的截_留率_的同时,将己烷石蜡溶液_的渗透通量提高_了25倍,为高_效低能耗_的膜分_离技_术用于淤浆聚乙烯技术生产过程_中溶剂脱蜡回收提_供了应_用前景。具体研_宄内容和主要结论如下:_{（1）}采_用双针静_电雾化法制^一_备了种层层堆叠_的G_O-_{P E I}有机-无机层状复合膜。其_中,氧化石墨烯纳米_片作为骨架,_以确保超薄无缺_陷的膜结构,而_PE I_作为交联剂连接相邻_的氧化石墨_烯纳米片进而提高膜结构稳定性。重要_的是,这_种膜表现_出极性溶_剂的快速渗透:水和丙酮_的渗透通量分别达到_{了4 6.2L}m_²Y^11_bar和_{1 4 6.8L}n^^-11_{hba r},优于大_多数报道_的氧化石墨烯基膜。_同时,有序交联_的层_间通道能够_精准_筛分工业染_料,截_留率在_{9 6}%_以上_{尺寸大于1.6nm。}此_外,该层状复合膜具有优_良的结_构、操_作、压_力和循环稳定性,这是传统层状膜难_以实现_{的。（2）}选_用商用聚酰胺有机溶_剂纳滤膜对己烷-石蜡溶液进行纳滤性能测试,_结_果表_明:在错流条件下,_商用膜N_F-_{7（）Mw⁼1 5 0 0￣2 0 0 0}和N_F-_{8（）Mw⁼3 0 0 0}对己烷_的通量_分别为²_{0.3 6Lr rf}!_^b a_r¹和²¹¹_{0.7Li rfh fbar},对石蜡截_留率为_{7 8}%和_{5 6}%;_由于_商用有机溶剂纳_滤膜_为匀质无孔膜,且分_离层较厚,造成通量较低且截留性能较差。因此,我们自主开发的氧化石墨烯-聚乙烯亚胺（GO-PEI）层状复合有机溶剂纳滤膜,在错流条件下,所开发层状复合膜对己烷的通量达到9.26 L m^-2 h^-1 bar^-1,是商业膜的25倍,对石蜡截留率提高至91%以上。研究结果初步证明所制备层状复合膜具有与商业膜相当的长周期操作稳定性。更多还原

【Abstract】 In recent years,with the rapid development of social economy,the global demand and consumption of polyethylene products are increasing significantly.How to deal with a large number of by-products of polyethylene production in an energy-saving and efficient way is a major problem in the environment-friendly situation.The effective solution of this problem also has a far-reaching impact and great significance on the development and prosperity of the petroleum and petrochemical industry.As a new separation technology,membrane separation technology has many outstanding advantages,such as high efficiency,energy saving,environmental protection,simple operation and so on.It has become one of the effective ways to solve the problem of social and economic sustainable development.The two-dimensional lamellar membrane has become a hot research direction of new nanofiltration membrane because of its ordered lamellar structure,easy to control chemical microenvironment,efficient molecular transfer characteristics and easy ultrathin preparation.In this study,the precise preparation of high-performance two-dimensional lamellar composite membrane and its application in the dewaxing of slurry polyethylene as the main research content,developed an ultrathin and stable GO-PEI lamellar composite membrane,and tried to apply it in the industrial application of slurry polyethylene dewaxing.The GO-PEI organic-inorganic lamellar composite membrane developed by electrostatic atomization technology can have high nanofiltration performance while maintaining high stability of structure and long-term operation,which can solve the trade-off effect between the permeance and rejection existing in traditional nanofiltration membrane to a certain extent.In addition,we develop the GO-PEI try used in slurry polyethylene dewaxing industrial application,while maintaining high paraffin molecular rejection rate at the same time,raised the permeance of paraffin solution by 25 times,for high efficiency low energy consumption of membrane separation technology used in slurry polyethylene production process in the solvent dewaxing recycling provides the application prospect.Specific research contents and main conclusions are as follows:（1）A lamellar organic-inorganic composite membrane consisting of graphene oxide（GO）and polyethylenimine（PEI）was prepared by two-needle electrostatic atomization.GO nanosheets serve as the skeleton to ensure ultrathin and defect-free membrane structure,while PEI cross-linked adjacent GO nanosheets keeps stable membrane structure.Importantly,this membrane achieves rapid polar solvent penetration:the permeance of water and acetone reach 46.2 L m^-2 h^-1 bar^-1 and 146.8 L m^-2 h^-1 bar^-1,respectively,which are superior to most reported GO-based membranes.At the same time,ordered cross-linked interlayer channels provide precise particle size rejection for industrial dyes（larger than 1.6 nm）with a rejection rate of over 96%.It is worth noting that the lamellar composite membrane has excellent structure,operation,pressure and cycle stability,which is difficult to achieve the traditional laminated membrane.（2）Commercial polyamide organic solvent nanofiltration membrane was used to test the nanofiltration performance of hexane and paraffin solution.The results showed that the fluxes of commercial membranes NF-7（with interception molecular weights MW=1500～2000）and NF-8（MW=3000）for hexane were 0.36 L m^-2 h^-1 bar^-1and0.7 L m^-2 h^-1 bar^-1,respectively,and the rejection rates for paraffin were 78%and 56%under the condition of cross-flow.Because the commercial organic solvent nanofiltration membrane is homogeneous and non-porous membrane and the separation layer is thick,the permeance is low and the permeance performance is poor.Therefore,the graphene oxide-polyethylenimine（GO-PEI）lamellar composite organic solvent nanofiltration membrane developed by us can achieve a hexane permeance of9.26 L m^-2 h^-1 bar^-1 under cross-flow conditions,which is 25 times higher than that of commercial membranes,and the rejection rate of paraffin is improved to more than91%.The results show that the prepared lamellar composite membrane has good stability for long period of operation compared with the commercial membrane.更多还原