科创中国

Ionic liquids are extensively used in many separation processes due to excellent dissolving ability for organic compounds and polymer materials, such as cellulose dissolution, Keratin dissolution. However, during the dissolution process, a small amount of degraded organic saccharides was produced, which could affect the strength of the regenerated fibers. Thus, it is required to find a suitable method for the removal of these saccharide molecules during the process of IL recovery. In this study, electrodialysis (ED) was used for the separation of these saccharide molecules from IL aqueous solution. In order to evaluate the separation performance of ED process, the influences of applied voltage, initial concentrations of IL and saccharide, and the initial volume ratio of the dilute solution to the concentrated solution on the current efficiency (η), recovery ratio (R_IL), removal ratio (R_S) and energy consumption (E) were systematically investigated. Experimental results showed that ED played a dual role in removing saccharides from the IL aqueous solution and concentrating IL. Under the optimized conditions, the removal efficiency of saccharides was 98.11% and IL concentration ratio is 2.63. Especially, the characterization results identified that the structure of the recovered IL was in well agreement with that of the fresh IL. All of these proved that ED might be an effective and green method to realize the separation of saccharides from the IL aqueous solution.

Weichao Li;Junfeng Wang;Yi Nie;Daoguang Wang;Hongxiang Xu;锁江 张

Separation and Purification Technology

2020-11-15

Y. H. Yao;Y. J. Chen;X. P. Zhang;锁江 张;保增 任;J. H. Wang

2011

Capturing CO ₂ from the flue gas has been considered as one of the effective and possible options to eliminate the global warming effect now. As new solvents, ionic liquids have attracted great attentions by the academies and industries on account of their low volatility, high selectivity and high solubility. In this work, a rigorous simulation flow sheet including absorption and desorption units, and taking ionic liquids compound as solvent has been established which uses ELECNRTL as the global thermodynamic model, and the binary interaction parameters between ionic liquids and the other components in the gas mixture are regressed based on the experimental data (Zhao et al, 2010). Some key operation parameters, such as solvent ratio and reflux ratio, were determined by sensitivity analysis. The results showed that the new process could capture carbon dioxide from the flue gas as high as 95%; the energy of reboiler was estimated to be reduced more than 20% compared with the MEA method. Furthermore, a multi-objective optimization was proposed and performed considering both the energy consumption and environmental impact (green degree) of the new CO ₂ capture process.

Y. J. Chen;Y. H. Yao;香平 张;锁江 张;保增 任

2011

Abstract: Colloidal mesoporous magnetite nanoparticles with tunable porosity were realized by a simple and scalable solvothermal route with the aid of AOT as ligands. AOT was used to induce the anisotropic crystal growth of smaller nanocrystals and restrain their tight aggregation so as to form more mesoscale pores. Morphologies and microstructures investigation by SEM and TEM revealed that the bigger nanoparticles were composed of smaller nanocrystals with an average size of 18 nm. A possible formation mechanism was proposed for the mesoporous nanoparticles. Study of nitrogen adsorption–desorption isotherm revealed that the Brunauer–Emmett–Teller (BET) specific surface area of mesoporous nanoparticles is up to 209 m²/g, resulting from the slit-shaped pores created by the aggregation of polyhedral nanocrystals. Magnetic properties study indicated that the as-prepared nanoparticles are superparamagnetic at room temperature. Optimized mesoporous magnetite nanoparticles exhibit a maximum Cr(VI) ion sorption capacity of 12.9 mmol/g, and its absorption behavior followed a Freundlich model. Microwave absorption study indicated that porous nanoparticles own higher permeability values than that of solid nanoparticles, leading to a higher dielectric loss in the frequency range of 2–18 GHz. Graphical Abstract: [Figure not available: see fulltext.]

Peng Shen;Haitao Zhang;锁江 张;Pei Yuan;Yang Yang;Qiang Zhang;Xixiang Zhang

Journal of Nanoparticle Research

2016-5-1

An environmentally benign catalytic system consisting of 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) and cellulose was developed for CO₂ chemical fixation with epoxides under metal-free and halide-free conditions. Due to the dual roles played by DBU and cellulose on the activations of CO₂ and epoxide, the reaction could be performed with high activity and selectivity. A possible catalytic cycle for the hydrogen bond assisted ring-opening of epoxide and the activation of CO₂ induced by DBU was proposed. The process herein represents a simple, ecologically safe and efficient route for CO₂ chemical fixation into high value chemicals. This journal is

Jian Sun;Weiguo Cheng;Zifeng Yang;Jinquan Wang;Tingting Xu;Jiayu Xin;锁江 张

Green Chemistry

2014-6

A multi-scale simulation method is proposed to enable screening of ionic liquids (ILs) as entrainers in extractive distillation. The 1,3-butadiene production process with acetonitrile (ACN) was chosen as a research case to validate the feasibility of the methodology. Ab initio calculations were first carried out to further understand the influence of ionic liquids on the selectivity of ACN and the solubility of C₄ fractions in [C_nMIM][PF₆](n = 2–8), [C₂MIM][X] (X = BF₄⁻, Cl⁻, PF₆⁻, Br⁻), by investigating the microstructure and intermolecular interaction in the mixture of C₄ fractions and several selected ionic liquids. It was found that the selectivity of the ionic liquid is determined by both its polarity and hydrogen-bonding ability. Based on the analysis, a suitable ionic liquid was chosen. With the ab initio calculation, a priori prediction of thermophysical data of the IL-containing system was performed with COSMO-RS. The calculation revealed that the selectivity of the extractive solvent was increased by an average of 3.64% after adding [C₂MIM][PF₆]. With above calculations, an improved ACN extraction distillation process using ILs as an entrainer was proposed, and a configuration for the new process was constructed. Based on the established thermodynamic models which have considered the properties from the molecular structure of ILs, process simulation was performed to obtain the process parameters which are important for the new process design. The simulation results indicated that the temperatures at the bottom of the extractive distillation column with the ionic liquid as an additive are lowered by an average of 3.1 °C, which is significant for inhibition of polymerization. We show that the ACN consumption using this process can be lowered by 24%, and the energy consumption can likewise be lowered by 6.62%.

Xiao Tian;香平 张;Lu Wei;Shaojuan Zeng;Lei Huang;锁江 张

Green Chemistry

2010-7-1

Ionic liquids (ILs) are a class of new green materials that have attracted extensive attention in recent decades. Many novel properties not evident under normal conditions may appear when ionic liquids are confined to a nanometer scale. As was observed in the experiment, an anomalous phase behavior from liquid to high melting point perfect crystal occurred when 1-n-butyl-3- methylimidazolium hexafluorophosphate ([bmim][PF₆]) ionic liquid was confined in a carbon nanotube. In this work, we performed molecular dynamics (MD) simulations for [bmim][PF₆] ionic liquid and provided direct structural evidence that the ionic crystallizes in a carbon nanotube. The ordered ionic arrangement in both the radial and the axial directions can be observed inside the channels of the CNTs to induce the form of crystallites. The ionic stacking and distributing can be determined by the sizes of the CNTs. Hydrogen bonds remain the dominant interactions between cations and anions when the ionic liquid enters into the CNT from the bulk phase. The free energies as the thermal driven forces were calculated, and it is found that it is very difficult for a single anion to enter into the channel of the CNT spontaneously. A more favorable way is through an ion-pair in which a cation "pulls" an anion to enter into the channel of the CNT together. It is predicted that other ionic liquids that possess similar structures, even including the pyridinium-based ionic liquids, can show higher melting points when confined in CNTs.

Kun Dong;Guohui Zhou;Xiaomin Liu;Xiaoqian Yao;锁江 张;Alexander Lyubartsev

Journal of Physical Chemistry C

2009-6-11

The MTHS (Molecular type homologous series matrix) was used to study the molecular modeling of distillate oil. The IMTHS (improved MTHS matrix) was developed to describe the composition of distillate oil on the basis of MTHS matrix. Transformation correlations were built to capture the molecular properties of each homologous series in the IMTHS matrix and to interrelate the molecular composition and bulk properties of the product streams. Two cases were illustrated for validation of the proposed model and methodology.

Long Yan;Zijun Wang;锁江 张;Haiping Shen;香平 张

Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section)

2012-4

The porous carbon material was synthesized from amphiphilic copolymer pluronic F127 as soft template and protonated chitosan solution as raw material, and the effects of pH value of solution and carbonization temperature on its pore structure, specific surface area and CO₂ adsorption capacity were examined. The result showed that the highest specific surface area of porous carbon material reached 457 cm²/g, its highest nitrogen content was 7.60%, and its highest surface nitrogen content 8.45% in the form of pyridine. Its highest CO₂ adsorption capacity reached 80.8 mg/g, and the adsorption efficiency was up to 0.274 mg/cm³.

Miao Na Feng;Jian Nan Gai;Guo Ying Zhao;Hong Ling Gao;锁江 张

Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering

2015-6-1

香平 张;锁江 张;Ping Jing Yao;Yi Yuan

Huaxue Gongcheng/Chemical Engineering

2003-6