共查询到19条相似文献,搜索用时 203 毫秒
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在丙烯的生产过程中,因丙烯/丙烷的分子大小及挥发性较为接近而难以高效分离,其精馏分离过程能耗较高。变压吸附(PSA)技术作为一种高效的气体分离技术,其核心是高效吸附剂的开发。该文综述了近年来国内外关于丙烯/丙烷分离吸附剂的研究进展。重点介绍了分子筛、碳分子筛以及金属-有机骨架材料(MOFs)在丙烯/丙烷分离上的应用。详细阐述了影响多孔材料丙烯/丙烷吸附分离比的关键因素,并对比了几种吸附分离材料的优缺点。研究发现,应根据实际应用场合、原料气体的组成、丙烯/丙烷相对含量以及吸附材料的实际使用条件等来选择合适的吸附剂。最后,对丙烯/丙烷吸附分离材料的开发及其在实际中的应用进行了展望。 相似文献
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为合理利用资源,提高资源利用率,研究了农林废弃物等各类生物质资源在环境保护领域的应用。采用柚子皮为原料,制备经柠檬酸改性的活性炭吸附剂,用于处理中性红染料并对其过程进行试验分析。探索了柠檬酸改性柚子皮基活性炭吸附剂对中性红染料的吸附机理,分析了吸附时间、吸附剂浓度、溶液pH值及吸附温度等因素对吸附效果的影响。试验结果表明,吸附时间、吸附温度及溶液pH值的增加,将有利于吸附过程的进行,吸附剂浓度的增加则会使得吸附过程的去除率呈现先增大后减小的现象,而吸附量持续降低。 相似文献
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为了研究氯化锶混合吸附剂-氨气工质对的非平衡吸附动力学模型,对混合比例为4:1(氯化锶:膨胀硫化石墨)的氯化锶-膨胀硫化石墨混合吸附剂的吸附与解吸性能进行了测试与研究。发现其非平衡吸附过程是双变量控制过程而不是单变量控制过程。通过对其等压吸附/解吸过程及解吸滞后现象进行进一步分析,建立了氯化锶混合吸附剂的动力学模型。分别用理论、实验及模型数据拟合吸附制冷过程的COP和制冷量,结果表明,所建立的非平衡动力学模型的拟合结果和实际结果吻合得很好。例如在蒸发温度为0℃、环境温度为25℃、热源温度为90.5℃以上时,拟合COP所带来的最大误差只有1.0%,而理论的平衡吸附性能计算所带来的最大误差为25.8%;理论得到的制冷量比实际值偏高188.1%,而拟合值只比实际值偏高2.1%。 相似文献
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吸附是发生在物质界面上的一种现象。多年来,许多科学工作者对固—气、固—液、液—液之间的吸附进行了大量的研究。得出了不少理论模型与经验公式。其中固—气之间的吸附理论较成熟。类比法是发展科学知识的一个重要方法。本文应用这一方法,根据现在已有的吸附理论去探讨其它的吸附过程,得出了一些试探性的结论。供读者参考。类比法是根据两个(或两类)对象之间在某些方面相似或相同而推出它们在其他方面也可能相似或相同的一种逻辑方法。许多重 相似文献
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《化工学报》2017,(6)
为了研究氯化锶混合吸附剂-氨气工质对的非平衡吸附动力学模型,对混合比例为4:1(氯化锶:膨胀硫化石墨)的氯化锶-膨胀硫化石墨混合吸附剂的吸附与解吸性能进行了测试与研究。发现其非平衡吸附过程是双变量控制过程而不是单变量控制过程。通过对其等压吸附/解吸过程及解吸滞后现象进行进一步分析,建立了氯化锶混合吸附剂的动力学模型。分别用理论、实验及模型数据拟合吸附制冷过程的COP和制冷量,结果表明,所建立的非平衡动力学模型的拟合结果和实际结果吻合得很好。例如在蒸发温度为0℃、环境温度为25℃、热源温度为90.5℃以上时,拟合COP所带来的最大误差只有1.0%,而理论的平衡吸附性能计算所带来的最大误差为25.8%;理论得到的制冷量比实际值偏高188.1%,而拟合值只比实际值偏高2.1%。 相似文献
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挥发性有机化合物(VOCs)对环境和人体健康均具有严重危害,而吸附法作为有效的VOCs脱除技术已得到广泛应用。在众多吸附剂中,金属有机框架材料(MOFs)以其极大的比表面积、可调节的孔径和可修饰性等优势,在VOCs脱除领域展示出良好的应用前景。本文首先介绍了在吸附过程中涉及到的吸附机理,从影响因素角度回顾了近年MOFs在VOCs吸附方面的研究进展。按照吸附质与吸附剂的几何结构、改性官能团、MOFs的金属位点、酸碱、水和碳材料复合等多个方面剖析了吸附过程中的影响因素,并将其分为内部影响因素和外部影响因素两大部分。针对影响因素归纳了提高吸附量的主要方法,并对MOFs吸附VOCs的吸附量进行了汇总。最后总结并展望了未来应用MOFs吸附VOCs的研究发展方向,期望为深入研究VOCs脱除技术提供有价值的参考。 相似文献
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An equilibrium theory simulator (Esim) for the simulation of cyclic adsorption processes is presented. The equations are solved with a Godunov upwind flux scheme that does not require either the evaluation of characteristics or shock equations or the imposition of a numerical entropy condition to track shocks. Esim is able to simulate non-trace and non-isothermal adsorption systems with any adsorption isotherm. Esim has been validated against gPROMS based simulations that use the full set of governing equations (including mass and heat transfer resistances and axial dispersion) carried out under conditions close to the limits where equilibrium theory is valid. Esim enables the establishment of bounds for the optimal performance of an equilibrium driven separation and requires only the measurement of adsorption isotherms. 相似文献
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柔性金属有机骨架材料(MOFs)具有高度有序的网络结构与可变形的骨架,其骨架结构会对外界的温度、压力及客体分子的刺激产生独特的结构响应。近几年来,柔性MOFs在气体吸附、气体分离、传感等领域显示出巨大的应用潜力。截至目前,研究者们对柔性MOFs的研究仅局限于对其结构形变的机理解释,而缺乏对柔性MOFs应用于相关化工过程的性能研究。本文着重对近年来柔性MOFs在气体吸附分离领域的研究进展进行了综述,并详细地分析了柔性MOFs结构与其气体吸附分离性能之间的构效关系。通过分子模拟结合实验,讨论了柔性MOFs结构对气体分子的平衡吸附与动力学扩散的影响。分析表明,设计合成具有良好吸附选择性与扩散性能的柔性MOFs是其应用于绿色、高效气体分离过程的重要发展方向。 相似文献
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Insights into the modeling of adsorption isotherm systems 总被引:1,自引:0,他引:1
Concern about environmental protection has increased over the years from a global viewpoint. To date, the prevalence of adsorption separation in the environmental chemistry remains an aesthetic attention and consideration abroad the nations, owning to its low initial cost, simplicity of design, ease of operation, insensitivity to toxic substances and complete removal of pollutants even from dilute solutions. With the renaissance of isotherms modeling, there has been a steadily growing interest in this research field. Confirming the assertion, this paper presents a state of art review of adsorption isotherms modeling, its fundamental characteristics and mathematical derivations. Moreover, the key advance of the error functions, its utilization principles together with the comparisons of linearized and non-linearized isotherm models have been highlighted and discussed. Conclusively, the expanding of the nonlinear isotherms represents a potentially viable and powerful tool, leading to the superior improvement in the area of adsorption science. 相似文献
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Stephan School Martin Schachtl Werner Sievers Peter Schweighart Alfons Mersmann 《化学工程与技术》1991,14(5):311-324
The knowledge of multicomponent adsorption equilibria is of great importance for the industrial design and application of adsorptive purification and separation processes. As the experimental determination of the required data is time-consuming and costly, theoretical help is desirable. This contribution presents and assesses the most common theoretical approaches to the calculation of multicomponent adsorption equilibria. The models are based on the assumption of an adsorbed solution, extension of the volume filling of micropores theory or statistical thermodynamics. These models are applied to different adsorptive/adsorbent systems with ideal and non-ideal equilibrium behaviour. It is established that, at low coverages of adsorbent surfaces, all theories provide good estimates of the adsorbed phase composition and total loading while, at high saturations, no model is completely satisfactory. 相似文献
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《Chemical engineering science》1985,40(7):1155-1167
The role of the desorbent in bulk separation processes in gaseous phase based on displacement chromatography is analysed in detail. The optimal desorbent is characterized by adsorptivity intermediate between those of the components to be separated. When using such a desorbent, classical chromatography and optimal recycle chromatography yield, according to the equilibrium theory, identical process performance. If a weak or a strong desorbent is used, then optimal recycle chromatography is the most convenient.When the appropriate desorbent can not be found, the use of two desorbents, one strong and the other weak, can lead to improved separation performances with respect to the use of one of the two desorbents alone. The optimal operation involves the use of two separate desorbent pulses of suitable duration, the first constituted by the pure strong desorbent and the second by the pure weak one.The analysis is developed using the equilibrium theory of multicomponent chromatography and a detailed pore diffusion model. The obtained results are experimentally verified in the case of the separation of a o- and p-chlorotoluene mixture through adsorption on zeolite X, investigating various possible desorbents. 相似文献
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稀有气体Xe/Kr的高效捕集分离是气体工业、核环境监测和乏燃料处理等领域的重要分离过程之一。氙与氪结构与极化率相似,传统低温精馏方法借助氙与氪的沸点差异实现二者分离,能耗巨大,吸附分离是较为理想的替代分离技术。以金属有机框架材料为代表的新型多孔材料具有结构多样性与高度可设计性,通过调节材料微孔表面的极化环境与孔道窗口结构,借助氙与氪极化率的微小差异,可实现对二者的精准辨识,有良好的吸附分离性能与应用前景。重点综述了金属有机框架材料在氙氪分离中的研究进展,归纳了材料的极化环境、孔道结构、框架柔性等因素对氙氪吸附分离性能的影响规律,探讨了金属有机框架材料在氙氪吸附分离研究中存在的问题和局限,并对未来发展方向进行了展望。 相似文献