多孔炭材料的制备及其电容法脱盐性能研究

发布时间：2018-03-04 18:44

本文选题：竹基活性炭　切入点：改性　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：当前由十环境污染严重、能源消耗加剧,人们对淡水资源的需求与日俱增,全球淡水资源止在逐年减少,大力开发海水淡化技术对于缓解现有淡水资源的消耗具有很重要意义。传统的蒸馏、反渗透、电渗析等海水淡化方法是以消耗大量能源为代价的,生产成本较高,积极开发能耗低、环境友好型的海水淡化新方法已迫在眉睫。电容法脱盐或电容去离子(CDI)技术是一种新兴的海水淡化技术,由于其具有能源消耗小、无二次污染、可循环利用等特点在海水淡化技术中显示出较好的前景。美国的Biosource、加拿大的Enpar和中国常州的爱思特等多家公司已生产出了电容法脱盐产品。在CDI的核心电极材料中,多孔炭材料由于具有良好的存储容量和优异的离子、电子传递性能使其得到广泛应用。寻找电导率高、比表面积大、孔结构发达孔径分布合适、比容量高、循环利用率高等性能优异的电极材料是CDl技术中的研究重点。本课题分别制备了竹基活性炭及其改性材料(不同比例的二氧化锰掺杂与石墨烯复合)、炭气凝胶等多孔炭,同时自制了电容法脱盐实验装置,考察了不同电极材料脱盐效果的区别,讨论了电容法脱盐技术中装置的操作因素影响。经过BET测试发现,竹基活性炭具有1747m2g-1的比表面积和2nm左右的孔径分布。通过共沉淀的方法分别制备了不同比例(wt1%、wt5%、wt10%、wt20%)二氧化锰掺杂的竹基活性炭,在恒流充放电测试中wt1%二氧化锰掺杂的竹基活性炭的比电容最高,达到了209F·g-1,在脱盐测试中,其脱盐效果达到10.30mg·g-1,脱除率为19.0%,具有很好的淡化盐水的效果。不同比例(wt1%、wt5%、wt10%、wt20%)石墨烯复合的竹基活性炭电极材料在石墨烯含量wt5%时,恒流充放电测试中具有很好的循环充放性能,比电容为121 F·g-1,在循环伏安测试中表现出了很好的双电层电容性能,在电容法脱盐测试中,其脱盐效果达到970mg·g-1。在制备的两种不同孔径的炭气凝胶的电容法测试中发现,孔径较大(19.6nm)的样品CRF300-20比较小的(9.8nm)具有更好的脱盐效果。在自制的电容法脱盐装置中,经过测试我们选择1.2V电压、10mL·min-1流速、1mm间距作为脱盐的操作条件。考察了不同浓度的进液浓度影响,发现处理液初试浓度的增大会使脱盐效果提高。最后,经过吸附-脱吸附循环测试,考察了竹基活性炭和炭气凝胶的重复利用性,经过三次循环后电极材料仍有很好的吸附性能。
[Abstract]:At present, due to the serious environmental pollution and the intensification of energy consumption, the demand for freshwater resources is increasing day by day, and the global freshwater resources are decreasing year by year. It is of great significance to develop seawater desalination technology to alleviate the consumption of existing freshwater resources. Traditional desalination methods such as distillation, reverse osmosis, electrodialysis and so on are at the cost of consuming a great deal of energy, and the production cost is high. It is urgent to develop a new method of seawater desalination with low energy consumption and environmental friendliness. The capacitive desalination or capacitive desalination (CDI) technology is a new seawater desalination technology, because of its low energy consumption and no secondary pollution. The characteristics of recycling have shown good prospects in seawater desalination technology. Several companies, such as Biosourcein in the United States, Enpar in Canada and Este in Changzhou, China, have produced capacitive desalination products. In the core electrode materials of CDI, Porous carbon materials have been widely used because of their good storage capacity and excellent ion transport properties. It is found that the porous carbon materials have high conductivity, large specific surface area, well developed pore size distribution and high specific capacity. The electrode materials with high recycling efficiency and excellent performance are the focus of CDl technology. In this paper, bamboo based activated carbon and its modified materials, such as different proportion of manganese dioxide doped with graphene, carbon aerogel and other porous carbon, were prepared, respectively. At the same time, the experiment device of capacitor desalting was made, the difference of desalting effect of different electrode materials was investigated, and the influence of operation factors on the desalting technology of capacitance method was discussed. The results of BET test showed that, Bamboo based activated carbon (BAC) has a specific surface area of 1747m2g-1 and pore size distribution of about 2nm. Bamboo based activated carbon (BAC) doped with manganese dioxide was prepared by coprecipitation method. In the constant current charge-discharge test, the specific capacitance of bamboo based activated carbon doped with wt1% manganese dioxide was the highest, reaching 209F 路g-1.In desalting test, the specific capacitance of bamboo-based activated carbon was 209F 路g-1.In desalination test, The desalination effect reached 10.30 mg 路g-1 and the removal rate was 19.0, which had a good effect on desalination of brine. The bamboo-based activated carbon electrode materials with different proportions of wt5 and wt10and graphite had good cyclic charge and discharge performance in constant current charge-discharge test when the content of graphene was wt5%. The specific capacitance is 121 F 路g -1, which shows a good double layer capacitance performance in cyclic voltammetry. In the capacitance desalination test, the desalination effect is 970 mg 路g -1. It is found in the capacitance test of two kinds of carbon aerogels with different pore sizes. The sample with larger pore diameter of 19.6nm) has better desalination effect than the sample with small diameter of 9.8nm. in the self-made capacitive desalting device, After testing, we selected 1.2V voltage of 10ml 路min-1 flow rate of 10ml 路min-1 as the operating condition of desalting. The effect of different concentration of liquid injection on desalination was investigated. It was found that the increase of initial concentration of the treated solution would improve the desalination effect. Finally, the desalination effect was improved with the increase of the initial concentration of the treated solution. The reusability of bamboo-based activated carbon and carbon aerogel was investigated by means of adsorption-desorption cycle test. After three cycles, the electrode material still had good adsorption performance.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11

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