VOC emission control using novel adsorbents and their regeneration

2014年，加拿大约有216万吨挥发性有机化合物(VOC)排放到大气中。这些排放的主要来源包括石油和天然气工业(34%)和使用有机溶剂的工艺(15%)。VOCs是地面臭氧的前体，许多VOCs可能致癌和/或具有神经毒性。因此，需要开发技术来以较低的成本有效地控制这些排放。技术还需要通过在可行的情况下促进回收和再利用来促进可持续发展。 吸附剂是具有较大比表面积和孔隙率的材料，有助于它们在一种称为吸附的过程中选择性地从气流中去除杂质(吸附物)。解吸与吸附相反(即从吸附剂中释放被吸附的物质)。通常在吸附之后进行再生，以通过解吸吸附物来清洁吸附剂。再生吸附(或解吸)是一种理想的空气污染控制技术，特别是对通常从溶剂型工艺排放的VOCs的捕获。带再生的吸附也可用于气体分离和提纯，作为碳氢化合物分离或胺吸收中能量更密集的低温蒸馏的替代品。金属有机骨架(MOF)是一类具有极高比表面积、高孔隙率和可调孔径的吸附剂，可用于吸附分离和污染控制过程。 为了加强对VOC排放的控制，以往的研究主要集中在改善吸附剂的吸附性能上。然而，关于提高吸附剂的再生性能，包括降低再生过程中的能耗等方面的研究很少或根本没有。与传统的蒸汽或热惰性气体再生相比，微波和电阻加热再生等新的再生技术因其更高的能量效率和解吸效果而成为更有效的再生技术。因此，有必要更好地了解MOF和吸附物的电和介电性质如何分别影响阻性再生和微波加热再生。 本研究的目的是：1)了解MOF的金属团簇对其电学和介电性能的影响；2)使用阻性加热再生MOF；3)使用微波加热再生MOF；以及4)使用非接触式微波传感器监测MOF的负载。 这项研究将通过更有效地捕获空气污染物排放、降低能源消耗和减少温室气体排放来改善空气质量，从而为加拿大的可持续发展做出贡献。它还将有助于在对加拿大具有战略重要性的领域培训高素质人员，以便在不损害环境质量的情况下改善工业活动。

About 2.16 megatonnes of volatile organic compounds (VOCs) were emitted to the atmosphere in Canada in 2014. Major sources of these emissions include the oil and gas industry (34%) and processes using organic solvents (15%). VOCs are precursors to ground-level ozone and many VOCs may be carcinogenic and/or neurotoxic. Therefore, technologies need to be developed to efficiently control these emissions, at lower cost. Technologies need also to foster sustainable development through promoting recycling and reusing whenever feasible. Adsorbents are material with large surface area and porosity which help them selectively remove impurities (adsorbate) from gas streams in a process called adsorption. Desorption is the reverse of adsorption (i.e. release of adsorbate from the adsorbent). Adsorption is typically followed by regeneration to clean the adsorbent by desorbing the adsorbate. Adsorption with regeneration (or desorption) is a desirable technique for air pollution control, particularly for VOCs capture, typically emitted from solvent-based processes. Adsorption with regeneration is also used for gas separation and purification as a replacement to the more energy intensive cryogenic distillation in separation of hydrocarbons or to amine absorption. Metal Organic Framework (MOF) is a class of adsorbents with extremely high surface area, high porosity and tunable pore sizes, that can be readily used for adsorptive separation and pollution control processes. To enhance VOC emissions control, previous research focused on improving the adsorption properties of adsorbents. However, little or no research has been conducted to enhance the regeneration properties of adsorbents including reducing the energy consumption during the regeneration process. New regeneration techniques such as microwave and resistive heating regeneration have emerged as more effective techniques compared to traditional regeneration with steam or hot inert gas due to their higher energy efficiency and desorption effectiveness. Hence, there is a need for better understanding of how the electric and dielectric properties of MOF and adsorbates affect resistive and microwave heating regeneration, respectively. The objectives of this research are: 1) Understand the impact of MOF's metal cluster on its electric and dielectric properties; 2) Regenerate MOFs using resistive heating; 3) Regenerate MOFs using microwave heating; and 4) Monitor MOFs loading using a non-contact microwave sensor. This research will contribute to sustainable development in Canada by improving the air quality through more effective capture of air pollutants emissions, lower energy consumption, and lower greenhouse gas emissions. It will also contribute to the training of high quality personnel in areas of strategic importance to Canada to improve industrial activities without compromising the quality of the environment.