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1.
This work describes facile synthesis of a porous polymeric material ( T-HCP ) using readily available reagents. Specifically, T-HCP is a thermally stable and hypercrosslinked polymer (HCP) that is essentially microporous with a high BET specific surface area (940 m2 g?1). Triptycene based polymers are known to feature internal free volume. Thus, the incorporation of triptycene units and extensive crosslinking by an external cross-linker in T-HCP makes it a promising adsorbent for small gas capture applications. Experimental results show that T-HCP demonstrated good CO2 capture capacity of 132 mg g?1 (273 K, 1 bar). Molecular hydrogen storage capacity of T-HCP is estimated to be 17.7 mg g?1 (77 K, 1 bar). T-HCP revealed high CO2/N2 selectivity (up to 63) as well as promising CO2/CH4 (up to 9.1) selectivity suggesting its potential applicability for CO2 separation from flue and natural gases. 相似文献
2.
Suisui Zhang Jingying Li Yan Nie Luyao Qiang Boyang Bai Zhiwei Peng Xiaoxun Ma 《中国化学工程学报》2022,42(2):236-244
HFC-134a is a widely used environment-friendly refrigerant. At present, China is the largest producer of HFC-134a in the world. The production of HFC-134a in China mainly adopts the calcium carbide acetylene route. However, the production route has high resource and energy consumption and large waste emission, and few of the studies addressed on the environmental performance of its production process. This study quantified the environmental performance of HFC-134a production by calcium carbide route via carrying out a life cycle assessment (LCA) using the CML 2001 method. And uncertainty analysis by Monte-Carlo simulation was also carried out. The results showed that electricity had the most impact on the environment, followed by steam, hydrogen fluoride and chlorine, and the impact of direct CO2 emissions in calcium carbide production stage on the global warming effect also could not be ignored. Therefore, the clean energy (e.g., wind, solar, biomass, and natural gas) was used to replace coal-based electricity and coal-fired steam in this study, showing considerable environmental benefits. At the same time, the use of advanced production technologies could also improve environmental benefits, and the environmental impact of the global warming category could be reduced by 4.1% via using CO2 capture and purification technology. The Chinese database of HFC-134a production established in this study provides convenience for the relevant study of scholars. For the production of HFC-134a, this study helps to better identify the specific environmental hotspots and proposes useful ways to improve the environmental benefits. 相似文献
3.
Lindsey Yue Alicia Bayon Wojciech Lipiński 《American Institute of Chemical Engineers》2021,67(8):e17267
The effects of particle size and carbon dioxide concentration on chemical conversion in engineered spherical particles undergoing calcium oxide looping are investigated. Particles are thermochemically cycled in a furnace under different carbon dioxide concentrations. Changes in composition due to chemical reactions are measured using thermogravimetric analysis. Gas composition at the furnace exit is evaluated with mass spectroscopy. A numerical model of thermal transport phenomena developed previously is adapted to match the physical system investigated in the present study. The model is used to elucidate effects of reacting medium characteristics on particle temperature and reaction extent. Experimental and numerical results show that (1) an increase in particle size results in a decrease in carbonation extent, and (2) the carbonation step consists of fast and slow reaction regimes. The reaction rates in the fast and slow carbonation regimes increase with increasing carbon dioxide concentration. The effect of carbon dioxide concentration and the distinction between the fast and slow regimes become more pronounced with increasing particle size. 相似文献
4.
The capture of particles by charged droplets was simulated by considering the electrostatic interactions of droplet-droplet and droplet-particle. The results indicate that the electrostatic repulsion between droplets leads to a dynamic accumulation mode of particles. However, the droplet spacing has an insignificant effect on the capture efficiency when the electrostatic deposition predominates. The increase of droplet charge remarkably improves the capture efficiency, in which the capture of fine particles accounts for the largest proportion. Compared to the droplet charge, the droplet size shows a limited improvement in the capture efficiency. Reducing the droplet velocity prolongs the capture time instead of enhancing the capture capacity per unit time, thereby improving capture efficiency. 相似文献
5.
低共熔溶剂(DESs)具有原料廉价易得、化学稳定性好、可设计、合成工艺简单、可循环使用和绿色环保等优点,在CO2捕集领域受到广泛关注。重点综述了近年来DESs用于CO2捕集的研究进展,总结了DESs捕集CO2的能力,分析了DESs捕集CO2的影响因素和DESs的循环使用性能,归纳了DESs捕集CO2的机理(包括物理吸收、化学吸收和物理化学协同吸收),并总结了CO2在DESs中的溶解度计算模型。分析发现,DESs捕集CO2的影响因素中,温度、压力和水含量(质量分数)均对CO2的捕集有影响,且DESs的结构是重要的影响因素;大部分DESs可循环使用;CO2在DESs中溶解度计算模型的建立有效推动了DESs捕集CO2的进一步发展。最后,指出了DESs捕集分离CO2所面临的主要问题并对进一步的研究工作进行了分析讨论。 相似文献
6.
Metal-organic framework-based CO2 capture: from precise material design to high-efficiency membranes
A low-carbon economy calls for CO2 capture technologies. Membrane separations represent an energy-efficient and environment-friendly process compared with distillations and solvent absorptions. Metal-organic frameworks (MOFs), as a novel type of porous materials, are being generated at a rapid and growing pace, which provide more opportunities for high-efficiency CO2 capture. In this review, we illustrate a conceptional framework from material design and membrane separation application for CO2 capture, and emphasize two importance themes, namely (i) design and modification of CO2-philic MOF materials that targets secondary building units, pore structure, topology and hybridization and (ii) construction of crack-free membranes through chemical epitaxy growth of active building blocks, interfacial assembly, ultrathin two-dimensional nanosheet assembly and mixed-matrix integration strategies, which would give rise to the most promising membrane performances for CO2 capture, and be expected to overcome the bottleneck of permeability-selectivity limitations. 相似文献
7.
醇胺法捕集CO2技术是一种较成熟的CO2捕集技术,具有吸收速度快、脱除效果好等显著优点,但其操作费用高、解吸能耗大。本文以降低醇胺法捕集烟气中CO2系统再生能耗为出发点,对常规醇胺法捕集CO2工艺统进行了节能优化研究。在常规工艺流程基础上引入压缩式热泵节能技术,并利用Aspen Plus软件建立了基于压缩式热泵技术的CO2捕集工艺流程模型。研究了压缩式热泵与机械蒸汽压缩回收(MVR)热泵、分流解吸、分布式换热、级间冷却4种节能工艺耦合,通过模拟计算与优化,结果说明了最佳节能工艺组合为“解吸塔压缩式热泵+贫液MVR热泵+分流解吸+级间冷却”耦合的CO2捕集工艺流程,当解吸塔顶气体分流比为0.25∶0.75、冷富液分流比为0.05∶0.95、级间冷却器位于吸收塔17块塔板位置、吸收塔输入冷量为-3.0GJ/h时,系统再生能耗最低,为2.533 GJ/tCO2,相比常规有机胺工艺(再生能耗4.204GJ/tCO2)节能率39.748%。 相似文献
8.
Shoji Nakamura Yuji Shibahara Atsushi Kimura Osamu Iwamoto Akihiro Uehara Toshiyuki Fujii 《Journal of Nuclear Science and Technology》2020,57(4):388-400
ABSTRACTThe thermal-neutron capture cross-section (σ0) and resonance integral (I0) were measured for the 135Cs(n,γ)136Cs reaction by an activation method and mass spectrometry. Because of difficulty in the preparation of pure 135Cs samples, we used 135Cs contained as an impurity in a normally available 137Cs standard solution. An isotope ratio of 135Cs and 137Cs in a standard 137Cs solution was measured by mass spectrometry to quantify 135Cs. Cesium-135 impurity along with the 137Cs standard solution was irradiated at the hydraulic conveyer of the research reactor in the Institute for Integral Radiation and Nuclear Science, Kyoto University. Wires of Co/Al and Au/Al alloys were used as neutron monitors to measure thermal-neutron fluxes and epi-thermal Westcott’s indices at an irradiation position. A gadolinium filter was used to measure the σ0, and a value of 0.133 eV was taken as the cut-off energy. Gamma-ray spectroscopy was used to measure induced activities of 137Cs, 136Cs and monitor wires. On the basis of Westcott’s convention, the σ0 and I0 values were derived as 8.57 ± 0.25 barn, and 45.3 ± 3.2 barn, respectively. The value of σ0 obtained in the present study agreed within the limits of uncertainties with the past-reported value of 8.3 ± 0.3 barn. 相似文献
9.
10.