Co-reporter:Xin-Juan Hou, Huiquan Li, Qinfu Liu, Hongfei Cheng, Peng He, Shaopeng Li
Applied Surface Science 2015 Volume 347() pp:439-447
Publication Date(Web):30 August 2015
DOI:10.1016/j.apsusc.2015.04.117
Highlights
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The results indicated that aminoalcohols exist with a mixing of intercalation and grafting.
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Aminoalcohols can form strong hydrogen bonds with Al octahedral sheet.
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The interaction between aminoalcohols and Si tetrahedral sheet are mainly attributed by vdW force.
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Aminoalcohols grafting or intercalating on kaolinite have strong reactivity as electron donors.
Co-reporter:Chenjian Yu;Huiquan Li;Xiaoping Jia
Clean Technologies and Environmental Policy 2015 Volume 17( Issue 3) pp:757-766
Publication Date(Web):2015 March
DOI:10.1007/s10098-014-0832-6
In China, coal fly ash (CFA) is the third-largest industrial waste and causes significant economic and environmental problems. Based on the technology of extracting alumina co-generated with calcium silicate and calcium silicon slag cement clinker, a multi-resource utilization of high-alumina coal fly ash system (MUCFA) is developed and thought to be a promising approach to utilize CFA. As a solid waste utilization system, the environmental effects of MUCFA, particularly heavy metal pollution, will significantly affect its promotion and development. Therefore, an integrated substance flow analysis (SFA) model is proposed to investigate the heavy metal flows and associated environmental effects of MUCFA. With the combination of sampling test and SFA, migration paths of heavy metals are figured out. The results of value flow analysis and environmental impact assessment depict an outline of MUCFA and indicate that CFA accounts for 24 % of the environmental impact and is not the major source of environmental impact. Chromium (Cr) and lead (Pb) exhibit similar migration paths but differ in the distribution rate of the processes. 57 % of the total Cr and 53 % of the total Pb are migrated into calcium silicon slag, while 24 % of Cr and 33 % of Pb are found in flue gas. In order to eliminate the potential environmental problems, some retrofits are implemented to optimize the heavy metal migration pathway. Moreover, several suggestions on making standards and regulations for waste utilization are provided to both government and companies for the development of MUCFA.
Co-reporter:Shumin Xin, Liguo Wang, Huiquan Li, Kelin Huang, Fengjiao Li
Fuel Processing Technology 2014 Volume 126() pp:453-459
Publication Date(Web):October 2014
DOI:10.1016/j.fuproc.2014.05.029
•38.6% of diethyl carbonate yield could be achieved over La2O3.•The catalytic activity could be attributed to the medium basicity.•The catalytic activity could be essentially regenerated by facile calcination.The catalytic synthesis of diethyl carbonate from urea and ethanol was investigated over various metal oxide catalysts. Among them, the lanthanum oxide prepared by precipitation method exhibited much higher catalytic activity. In particular, 38.6% of DEC yield could be achieved at the reaction conditions of ethanol/urea molar ratio of 10, reaction temperature of 210 °C within 3 h over La2O3-500. The catalyst structures and surface properties were studied by N2 adsorption, XRD, FT-IR and CO2-TPD. On the basis of these results, it can be inferred that the high catalytic activity could be attributed to the abundant medium basicity of lanthanum oxide. Importantly, as confirmed by ICP-OES test, there was no obvious leaching of La into the resulting mixture. This phenomenon indicated that La2O3-500 was very stable during the reaction and behaved as a heterogeneous basic catalyst. In addition, the facile calcination of the used catalyst could provide an efficient way to regenerate the catalytic activity.
Co-reporter:Hui-Quan Li, Yan Cao, Xin-Tao Li, Li-Guo Wang, Feng-Jiao Li, and Gan-Yu Zhu
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 2) pp:626-634
Publication Date(Web):December 8, 2013
DOI:10.1021/ie4029945
A nonphosgene route for synthesis of dimethylhexane-1,6-dicarbamate (HDC) by methoxycarbonylation of 1,6-hexanediamine (HDA) with dimethyl carbonate (DMC) using AlSBA-15 as a heterogeneous catalyst was proposed. Catalyst was characterized, and effects of catalyst concentration, DMC to HDA molar ratio, reaction temperature, and reaction time were investigated. Results showed that AlSBA-15 exhibited high catalytic activity because of its large surface area and average pore diameter as well as acidity because of impregnation with Al. Under the optimum conditions of 5% Al incorporation, 5% catalyst concentration, 6:1 DMC to HDA molar ratio, 70 °C reaction temperature, and 35 h reaction time, the HDC yield reached 84.2%. Catalyst was easily separated, and no obvious deactivation was found even after the catalyst was used four times. Interactions of AlSBA-15 with the substrates were also studied by quasi in situ Fourier transform infrared (FTIR), and a possible reaction mechanism was proposed.
Co-reporter:Peng He, Huiquan Li, Xinjuan Hou
Chemical Physics Letters 2014 Volume 593() pp:83-88
Publication Date(Web):11 February 2014
DOI:10.1016/j.cplett.2013.12.044
•Developing relationships for predicting diffusion of CH4 in zeolites and MOF systems.•Extending scaling laws for describing diffusion of fluid in nanoporous materials.•Ascertaining the effects of pore types on the results of excess-entropy scaling laws.Molecular simulation was conducted to test the validity of two excess entropy scaling laws proposed by Rosenfeld and Dzugutov for extending their use in describing the diffusion of CH4 molecules through zeolites and metal–organic frameworks. The functional relationships between self-diffusivity and excess entropy formulated by the two laws are found to hold with the modified pre-exponential scaling parameters. Based on this finding, new relations for the two scaling laws are proposed for predicting the diffusivities of CH4 molecules in nanoporous materials within a wide range of concentrations and temperature conditions.Graphical abstractReduced self-diffusivity data (symbols) versus negative excess entropy per particle for CH4 diffusion in various zeolites using the modified Rosenfeld scaling relations.
Co-reporter:Jian-Fei Liu, Yan Cao, Mao-Hua Yang, Xue-Jing Wang, Hui-Quan Li, Jian-Min Xing
Chinese Chemical Letters 2014 Volume 25(Issue 11) pp:1485-1488
Publication Date(Web):November 2014
DOI:10.1016/j.cclet.2014.06.001
A simple and efficient method of enhancing biomass saccharification by microwave-assisted pretreatment with dimethyl sulfoxide/1-allyl-3-methylimidazolium chloride is proposed. Softwood (pine wood (PW)), hardwoods (poplar wood, catalpa bungi, and Chinese parasol), and agricultural wastes (rice straw, wheat straw, and corn stover (CS)) were exploited. Results showed that the best pretreatment effect was in PW with 54.3% and 31.7% dissolution and extraction ratios, respectively. The crystal form of cellulose in PW extract transformed from I to II, and the contended cellulose ratio and glucose conversion ratio reached 85.1% and 85.4%, respectively. CS after steam explosion achieved a similar pretreating effect as PW, with its cellulose hydrolysis ratio reaching as high as 91.5% after IL pretreatment.1-Allyl-3-methylimidazolium chloride pretreatment is used to enhance biomass saccharification. Softwood, hardwoods, and agricultural wastes were exploited. PW reached as high as 85.4% hydrolysis ratio after IL pretreatment. Biomass structure plays a key role in enzymatic hydrolysis ratio.
Co-reporter:Fangfang Zhang;Huiquan Li;Bo Chen
Frontiers of Environmental Science & Engineering 2014 Volume 8( Issue 2) pp:256-266
Publication Date(Web):2014 April
DOI:10.1007/s11783-013-0585-1
Vanadium is a vital strategic resource, and vanadium metabolism is an important part of the national socio-economic system of China. This study conducts accounting and scenario analysis on the life cycle of vanadium metabolism in China. Based on the characteristics of vanadium life cycle and substance flow analysis (SFA) framework, we present a quantitative evaluation of a static anthropogenic vanadium life cycle for the year 2010. Results show that anthropogenic vanadium consumption, stocks, and new domestic scrap are at 98.2, 21.2, and 4.1 kt, respectively; new scrap is usually discarded. The overall utilization ratio of vanadium is 32.2%. A large amount of vanadium is stockpiled into tailings, debris, slags, and other spent solids. A scenario analysis was conducted to analyze the future developmental trend of vanadium metabolism in China based on the SFA framework and the qualitative analysis of technology advancement and socio-economic development. The baseline year was set as 2010. Several indicators were proposed to simulate different scenarios from 2010 to 2030. The scenario analysis indicates that the next 20 years is a critical period for the vanadium industry in China. This paper discusses relevant policies that contribute to the improvement of sustainable vanadium utilization in China.
Co-reporter:Ganyu Zhu, Huiquan Li, Yan Cao, Haitao Liu, Xintao Li, Jiaqiang Chen, and Qing Tang
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 12) pp:4450
Publication Date(Web):March 3, 2013
DOI:10.1021/ie302659q
This study presents a clean, novel, and highly efficient system for the decomposition of methyl N-phenyl carbamate (MPC) to phenyl isocyanate (PI). MPC conversion of high as 89% and PI selectivity of almost 100% were obtained using chlorobenzene solvent under high pressure without any catalyst. The effects of temperature and time on the conversion of MPC were investigated, and the apparent kinetics model of MPC decomposition reaction was established. Results indicate that the decomposition of MPC is a pseudo-first-order reaction with Arrhenius parameters of Ea = 71.28 kJ/mol and A = 2.74 × 105 min–1, and the model correlated well with experimental data. This study provides not only a new and clean system for the highly efficient production of PI, but also a guide for the design of reactors in the isocyanate industry.
Co-reporter:Xin-Juan Hou ; Peng He ; Huiquan Li ;Xingrui Wang
The Journal of Physical Chemistry C 2013 Volume 117(Issue 6) pp:2824-2834
Publication Date(Web):January 7, 2013
DOI:10.1021/jp310517r
An computational study using density functional theory and grand-canonical Monte Carlo simulation that explore the adsorption mechanism of C2H2, CO2, and CH4 to metal–organic frameworks (MOFs) with coordinatively unsaturated metal sites (M-MOF-74, M = Mg and Zn) has been carried out. The theoretical studies reveal that open metal sites have important roles in adsorption. The high CO2 adsorption ability of M-MOF-74 is due to the strong Lewis acid and base interactions between metal ions and oxygen atom of CO2, as well as carbon atom of CO2 with oxygen atoms in organic linkers. Meanwhile, the high C2H2 adsorption for M-MOF-74 is contributed by the strong complexation between the metal ions and the π orbital of C2H2. The different adsorption mechanisms of CO2, C2H2, and CH4 in M-MOF-74 can qualitatively explain the high CO2 selectivity in CO2/CH4 mixture and high C2H2 selectivity in C2H2/CH4 mixture. Energy decomposition analysis reveals that electrostatic energy, exchange energy, and repulsive energy are key factors in the binding strength of gas molecules on M-MOF-74. The preferential adsorption sites are confirmed to be located near the five-coordinate metal ions decorating the edges of the hexagonal channels. The elucidation of the adsorption mechanism at the molecular level provides key information for designing novel MOFs with high capacity and selectivity for CO2 from light hydrocarbon mixtures.
Co-reporter:Dehua Xu, Huiquan Li, and Zhibao Li
Journal of Chemical & Engineering Data 2013 Volume 58(Issue 11) pp:3110-3117
Publication Date(Web):October 8, 2013
DOI:10.1021/je400551d
The vapor pressures of methylcarbamate (MC) and methyl n-phenyl carbamate (MPC), at different temperatures ranging from (341.45 to 418.45) K, have been measured using the quasi-static ebulliometric method. The experimental data were fitted to the Antoine equation with the overall average absolute deviation of pressure of 0.06 kPa. Isobaric vapor–liquid equilibrium (VLE) data were also determined for the MC and MPC system at (1.00, 2.00, 4.00, 6.00, and 8.00) kPa by the same method and were correlated with nonrandom two-liquid (NRTL) and Wilson models. The both model parameters were obtained with the overall average absolute deviation of temperature 0.82 K and 0.81 K. The relative volatility of the binary system was calculated and was more than 1 by far, indicating that high-purity MPC can be obtained from the binary mixture by distillation technology.
Co-reporter:Chen Ye Wang, Hui Quan Li, Li Guo Wang, Yan Cao, Hai Tao Liu, Yi Zhang
Chinese Chemical Letters 2012 Volume 23(Issue 11) pp:1254-1258
Publication Date(Web):November 2012
DOI:10.1016/j.cclet.2012.10.001
The mechanism for synthesis of 4,4-methylenedianiline (MDA) via condensation reaction of aniline with formaldehyde has been studied extensively in this paper. The intermediate and by-products were isolated and identified. The combination of isotope labeling and HPLC–MS characterizations disclosed that the reaction proceeded through an SN2 reaction mechanism. Moreover, the effect of aniline/formaldehyde molar ratio on the formation of MDA was investigated. This work would be of significance to understand the reaction mechanism deeply and provide valuable information for further improving the yield of desired product.
Co-reporter:Xingrui Wang, Huiquan Li, and Xin-Juan Hou
The Journal of Physical Chemistry C 2012 Volume 116(Issue 37) pp:19814-19821
Publication Date(Web):August 27, 2012
DOI:10.1021/jp3052938
An amine-functionalized metal organic framework, TEPA-MIL-101, was prepared by grafting tetraethylenepentamine (TEPA) on the coordinatively unsaturated Cr(III) sites of MIL-101 for the selective adsorption of CO2 over CO. The adsorbents were characterized using various techniques. The results indicate that the TEPA molecule was successfully grafted on Cr(III) without destroying the intrinsic structure of MIL-101. Isotherms for CO2 and CO adsorption on MIL-101 and TEPA-MIL-101 were obtained to determine the effects of the grafted TEPA on the CO2 adsorption capacity and selectivity. The results show that the CO2 capacity on TEPA-MIL-101 was higher than that on MIL-101 at lower pressures, whereas the CO capacity sharply decreased. The selectivity for CO2 over CO was clearly improved from 1.77 to 70.2 at 298 K and total pressure 40 kPa. The density functional theory calculation for the adsorption of CO2 and CO on TEPA indicates that the bonding energy of CO2 is obviously higher than that of CO. Analysis of the cyclic adsorption performance reveals the high stability of the adsorbent. On the basis of the experimental and simulation results, the grafting of amines on coordinatively unsaturated sites of metal organic frameworks is an effective method of achieving selective adsorption of CO2 over CO.
Co-reporter:Kelin Huang, Ben Wang, Yan Cao, Huiquan Li, Jinshu Wang, Weijiang Lin, Chaoshi Mu, and Dankui Liao
Journal of Agricultural and Food Chemistry 2011 Volume 59(Issue 10) pp:5376-5381
Publication Date(Web):April 1, 2011
DOI:10.1021/jf104881f
Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The 13C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.
Co-reporter:Xingrui Wang, Huiquan Li, Haitao Liu, Xinjuan Hou
Microporous and Mesoporous Materials 2011 Volume 142(2–3) pp:564-569
Publication Date(Web):July 2011
DOI:10.1016/j.micromeso.2010.12.047
Tetraethylenepentamine (TEPA) was incorporated into as-synthesized mesoporous silica MSU-1 with cheap sodium silicate as silica source to create TEPA/MSU-1, an adsorbent having high adsorption capacity for carbon dioxide. The adsorbents were characterized by X-ray diffraction (XRD), N2 adsorption/desorption, thermogravimetry (TG), and Flourier transform infrared (FTIR) spectrometry. The XRD results indicated that the adsorbents preserved the mesostructure of MSU-1 after TEPA was loaded. However, the surface area decreased dramatically, indicating that the pores are occupied by amine. TG patterns showed that the adsorbents are thermally unstable at temperatures above 200 °C. The FTIR results suggested that CO2 interacts with TEPA to form alkalammonium carbamate. CO2 adsorption isotherms measured at different temperatures revealed that the optimal adsorption temperature is 75 °C. Temperature-programmed desorption (TPD) of CO2 showed that the desorption of CO2 achieved maximal desorption rate at about 100 °C, and so is appropriate for thermal swing adsorption of CO2 from flue gas. The adsorption capacity of TEPA/MSU-1 with a different TEPA content was calculated through CO2 breakthrough curves. As a result, 50 wt% of TEPA supported on as-synthesized MSU-1 achieved the highest capacity at 3.87 mmol/g.Graphical abstractResearch highlights► An adsorbent with tetraethylenepentamine loaded on MSU-1 was made and characterized. ► 50 wt% of TEPA supported on as-synthesized MSU-1 achieved the highest capacity. ► It has an excellent selectivity for CO2/N2 system. ► The optimal adsorption temperature is 75 °C and CO2 is thoroughly released at 100 °C.
Co-reporter:Yixia Pei, Huiquan Li, Haitao Liu, and Yi Zhang
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 4) pp:1955-1961
Publication Date(Web):January 19, 2011
DOI:10.1021/ie1017095
Methylene diphenyl dicarbamate (MDC) is a key intermediate in the non-phosgene manufacture of methylene diphenyl diisocyanate. The synthesis of MDC by methoxycarbonylation of methylene dianiline (MDA) with dimethyl carbonate in the presence of lead acetate catalyst, which showed high catalytic activity, was studied. Complete conversion of MDA and 98.10% yield of MDC were achieved under optimum conditions. To quantify the influence of both the temperature and reaction time, the kinetic parameters were investigated in the presence of Pb(OAc)2·3H2O. A consecutive reaction model was established by simplifying the methoxycarbonylation process, and the two steps were confirmed to be first-order reactions by the integral test method and the numerical differential method, respectively. The results showed that the activation energies of the two steps are 175.84 and 177.92 kJ/mol, with the frequency factors being 1.91 × 1020 and 1.98 × 1020, respectively. Based on the kinetic model obtained, the progress of the reaction can be calculated under given conditions.
Co-reporter:Yan Cao, Huiquan Li, and Jun Zhang
Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 13) pp:7808-7814
Publication Date(Web):May 14, 2011
DOI:10.1021/ie2004362
Cellulose acetate butyrate (CAB) with butyryl content of 6–47 wt % was homogeneously synthesized in 1-allyl-3-methylimidazolium chloride (AmimCl) in a single step without using any catalysts. The effects of different acylating agents (acetic anhydride and butyric anhydride) addition methods and reaction conditions on the acyl content of CABs were investigated. Synthesized CABs were characterized by FTIR, NMR, solubility, and thermal analysis. The acylating agents addition method influences the butyryl content, substituent distribution within the anhydroglucose units (AGU), and the properties of CAB. The CAB obtained with butyryl content greater than 38% is completely soluble in 2-methyl–ethyl ketone, 1,2-dichloromethane, ethyl acetate, and butyl acetate. After the mix-acylation, AmimCl can be easily recycled and reused. This study provides a novel way for the clean production of CAB under mild conditions for future industrial applications.
Co-reporter:Weijun Bao, Huiquan Li and Yi Zhang
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 5) pp:2055-2063
Publication Date(Web):January 29, 2010
DOI:10.1021/ie801850s
Indirect CO2 mineral sequestration, which could make CO2 fixate into precipitated calcium carbonate (PCC) of value-added products, is an important technology that is used to reduce greenhouse gas emissions economically. It can be conducted in two steps, one of which has been investigated in the previous paper. In this work, extraction of calcium ions from steelmaking slag using a novel leaching medium, which involves organic solvent tributyl phosphate (TBP), acetic acid, and ultrapure water, was studied. Several operating variables, including stirring speed, phase-volume ratio, organic solvent-to-solid ratio, initial acetic acid concentration, acid-to-slag ratio, reaction temperature, and reaction time were investigated. It was found that the leaching process could be divided into three regions according to the acid-to-slag ratio. The first region below 0.5 g/g was characterized by the acid-to-solid ratio; the second region above 0.5 g/g but below 1.0 g/g was characterized by the acid-to-solid ratio; and the third region above 1.0 g/g was characterized by the acid-to-solid ratio. When the acid-to-solid ratio was below 1.0 g/g, only Ca and Mg could be leached with the maximum leached ratios of 75% and 35%, respectively. Moreover, the leaching behaviors of Ca, Mg, Fe, Al, and Si were greatly affected by reaction temperature and reaction time. Results show that the calcium ions can be effectively and selectively extracted from the steelmaking slag and that the reaction medium can be recovered and recycled with high efficiency. These are the keys to indirect CO2 mineral sequestration.
Co-reporter:Yan Cao;Huiquan Li;Yi Zhang;Jun Zhang;Jiasong He
Journal of Applied Polymer Science 2010 Volume 116( Issue 1) pp:547-554
Publication Date(Web):
DOI:10.1002/app.31273
Abstract
Cornhusk cellulose was regenerated using the ionic liquids viz., 1-allyl-3-methylimidazolium chloride (AmimCl) and 1-ethyl-3-methylimidazolium acetate (EmimAc). The cast cellulose films were characterized by FTIR, WAXD and SEM techniques. Their mechanical properties were also studied. These studies indicated that AmimCl and EmimAc are good solvents for the regeneration of cornhusk cellulose. The regenerated cornhusk cellulose (RCC) was found to be cellulose (II) with dense structure. The films cast from AmimCl exhibited good mechanical properties; the tensile modulus and strength were as high as 6 GPa and 120 MPa respectively, whereas these values for those films cast using EmimAc were found to be 4.1 GPa and 47 MPa respectively. Further, it was observed that after regeneration, the solvents could be effectively recycled. Thus a novel nonpolluting process of forming RCC films from agricultural waste was developed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Xin-Juan Hou and Huiquan Li
The Journal of Physical Chemistry C 2010 Volume 114(Issue 32) pp:13501-13508
Publication Date(Web):July 28, 2010
DOI:10.1021/jp103778j
Understanding the CO2 adsorption mechanism of zeolitic imidazole frameworks (ZIFs) is the key to improving the adsorption ability of new metal–organic framework materials for gas capture applications and designing novel frameworks. In this work, the ONIOM2(B3LYP/6-31G**:UFF) method is used to investigate the interactions between CO2 and CO molecules with ZIF-68 and ZIF-69, respectively. Calculation results indicate that a strong Lewis acid–base interaction exists between the gas molecules and nitro groups of 2-nitroimidazole linkers, which thus prevents the entry of gas molecules into the small pores of ZIFs. The simultaneous interaction of both oxygen atoms of CO2 with the H atoms of the benzimidazole (5-chlorobenzimidazole) rings in the large pores results in the high CO2 selectivity observed for both ZIFs. The presence of electron-withdrawing groups in the phenylimidazole linker of ZIF increases the interaction between the oxygen atoms of CO2 and hydrogen atoms of the phenyl rings in its large pores. This work elucidates the adsorption mechanism of CO2 and CO to ZIFs at the molecular level and provides useful information for the design of MOFs in gas purification and separation applications.
Co-reporter:Tao Li;Huiquan Li;Guotong Qin;Haitao Liu;Yixia Pei
Frontiers of Chemistry in China 2010 Volume 5( Issue 1) pp:99-103
Publication Date(Web):2010 March
DOI:10.1007/s11458-009-0207-4
Methylene diphenyl dicarbamate (MDC) was synthesized from methyl phenyl carbamate (MPC) and trioxane using sulfuric acid (H2SO4) as catalyst. The effects of reaction temperature, reaction time, molar ratio of reactants and the content of catalyst have been studied in details. The results showed that H2SO4 exhibited high catalytic activity with the merits of moderate reaction velocity. Under the conditions of n(MPC)/n(trioxane) = 3:1, reaction temperature of 95°C, reaction time of 3.5 h and 30% H2SO4, the conversion of MPC reached 99.0% with the selectivity of MDC 81.6%. Moreover, the H2SO4 catalyst was reused five times without obviously activity decrease. Based on the identification of byproducts, a possible reaction mechanism was proposed.
Co-reporter:Hui Zhang;HuiQuan Li;Qing Tang;WeiJun Bao
Science China Technological Sciences 2010 Volume 53( Issue 1) pp:85-92
Publication Date(Web):2010 January
DOI:10.1007/s11431-010-0029-0
Extensive use of carbon based fuel is the main inducement for global warming and more extreme weather. Reducing carbon dioxide emission and enhancing energy use is a common subject in steel industry. In the integrated steel plant, decreasing carbon dioxide emission must consider energy balance in the whole iron and steel works, and secondary energy must be actively utilized. As promising blast-furnaces, top gas recovery blast furnace (TGR-BF) and oxygen blast furnace have been investigated. In this paper, conceptual TGR blast furnace and oxygen blast furnace are proposed. Base on the idea of blast furnace gas de-CO2 circulating as reducing agent and the idea of pure oxygen blast decreasing the thermal reserve zone temperature, process modeling is conducted with ASPEN Plus. It is shown that the developed model reasonably describes the energy balance and mass balance feature of the furnace, and provides basic thermodynamic condition for furnaces. The effects of changes in different operation conditions are studied by sensitivity analysis and reference data from simulation.
Co-reporter:Weijun Bao;Huiquan Li ;Yi Zhang
Crystal Research and Technology 2009 Volume 44( Issue 4) pp:395-401
Publication Date(Web):
DOI:10.1002/crat.200800065
Abstract
Monodispersed calcium carbonate microspheres were prepared by carbonating a calcium acetate aqueous solution with CO2 gas at a high pressure of 40 bar and a high temperature of 80 °C after 60 minutes of reaction. The products were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD pattern showed that the crystal polymorph of the as-prepared monodispersed microspheres was aragonite. The SEM images also displayed needle-like aragonite self-organized into microsphere superstructure with diameters ranging from 5 to 15 μm. Analysis of the formation mechanism of the calcium carbonate microsphere superstructure revealed that the rod-dumbbell-sphere morphogenesis mechanism along with the phase transformation of vaterite to aragonite was responsible for the growth of the monodispersed aragonite microspheres. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Co-reporter:Yan Cao, Jin Wu, Tao Meng, Jun Zhang, Jiasong He, Huiquan Li, Yi Zhang
Carbohydrate Polymers 2007 Volume 69(Issue 4) pp:665-672
Publication Date(Web):2 July 2007
DOI:10.1016/j.carbpol.2007.02.001
Cellulose samples extracted from cornhusk have been successfully acetylated in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). Without using any catalyst, cornhusk cellulose acetates (CCAs) with the degree of substitution (DS) in a range from 2.16 to 2.63 were prepared in one-step. Under the homogeneous state, the DS value of CCAs was easily controlled by the acetylation time. The obtained CCAs were characterized by means of FT-IR, 13C NMR, DSC, TGA, and a mechanical test. The NMR results showed that the distribution of the acetyl moiety among the three OH groups of the anhydroglucose unit shows a preference at the C6 position. The CCAs exhibited good solubility in some organic solvents, such as acetone and DMSO. The cast CCA films from their acetone solutions had good mechanical properties. At the end of each acetylation of cornhusk cellulose, the ionic liquid AmimCl could be effectively recovered. Therefore, this study presents a promising approach and “green process” to make use of crop by-products.
Co-reporter:Hongtao Jiang, Huiquan Li, Hongbin Xu, Yi Zhang
Fuel Processing Technology 2007 Volume 88(Issue 10) pp:988-995
Publication Date(Web):October 2007
DOI:10.1016/j.fuproc.2007.05.007
Ni/MgxTi1 − xO catalysts were prepared through a wet impregnation method by dispersing Ni on MgxTi1 − xO composite oxides obtained via a sol–gel technique. The Ni/MgxTi1 − xO catalysts were characterized by various means including ICP–OES, BET, XRD, H2–TPR, SEM, and TG. No free NiO peak was found in all XRD patterns of the Ni/MgxTi1 − xO catalysts. The H2–TPR and chemisorption results indicated that adding Ti to the NiO–MgO system obstructed the formation of solid solution, and thus increased the reducibility of the catalysts. The prepared MgxTi1 − xO composite oxides had the same ability to disperse Ni as TiO2 and MgO. The tri-reforming (simultaneous oxygen reforming, carbon dioxide reforming, and steam reforming) of methane over Ni/MgxTi1 − xO catalysts was carried out in a fixed bed flow reactor. The conversions of CH4 and CO2 can respectively be achieved as high as above 95% and 83% over Ni/Mg0.75Ti0.25O catalyst under the reaction conditions. The activity of Ni/Mg0.75Ti0.25O and Ni/Mg0.5Ti0.5O did not decrease for a reaction period of 50 h, indicating their rather high stability. The experimental results showed that the nature of support, the interaction between metal and support, and the ability to be reduced played an important role in improving the stability of catalysts.
Co-reporter:Jun Jie Gao, Hui Quan Li, Yi Zhang
Chinese Chemical Letters 2007 Volume 18(Issue 2) pp:149-151
Publication Date(Web):February 2007
DOI:10.1016/j.cclet.2006.12.014
Synthesis of methyl N-phenyl carbamate from dimethyl carbonate and 1,3-diphenyl urea was investigated under atmospheric pressure. The results showed that homogenous catalyst sodium methoxide had the excellent activity to efficiently catalyze the synthesis of methyl N-phenyl carbamate under atmospheric pressure.
Co-reporter:Kelin HUANG, Rui WU, Yan CAO, Huiquan LI, Jinshu WANG
Chinese Journal of Chemical Engineering (May 2013) Volume 21(Issue 5) pp:577-584
Publication Date(Web):1 May 2013
DOI:10.1016/S1004-9541(13)60524-8
Molecular distillation was used to recover ionic liquid (IL) 1-allyl-3-methylimidazolium chloride (AmimCl) in homogeneous cellulose acetylation. The five factors that affect the separation efficiency of molecular distillation, namely, feed flow rate, distillation temperature, feed temperature, wiper rotating speed, and distillation pressure, are discussed. The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design. The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions. The purity of recycled IL the 5th time reached 99.56%. FT-IR (Fourier transform infrared spectroscopy) and 1H NMR (nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed. This work proves that AmimCl has excellent reusability, and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.
Co-reporter:Haitao Liu, Zhao Zhang, Huiquan Li, Qingze Huang
Journal of Natural Gas Chemistry (May 2011) Volume 20(Issue 3) pp:311-317
Publication Date(Web):1 May 2011
DOI:10.1016/S1003-9953(10)60180-6
AbstractThe intrinsic kinetics of oxidative dehydrogenation of propane with CO2 has been investigated over Cr/MSU-1 catalyst in a fixed bed reactor. Without limitations of both internal and external diffusion, intrinsic kinetic data were obtained under the following conditions: 490-530 °C, space velocity of 3600-6000 mL·h−1·g−1 and 3/1 molar ratio for CO2/C3H8 under normal pressure. Based on Langmuir-Hinshelwood mechanism, the kinetic models were established, and they were validated by statistical analysis. The parameters were estimated using Simplex Method combined with Universal Global Optimization Algorithm. The model, taking the surface reaction process as the rate-determining step, is the best one in agreement with the experimental data.
Co-reporter:Hui Zhang, Liang Dong, Hui-quan Li, Bo Chen, Qing Tang, Tsuyoshi Fujita
Sustainable Energy Technologies and Assessments (June 2013) Volume 2() pp:67-80
Publication Date(Web):1 June 2013
DOI:10.1016/j.seta.2013.03.003
As an energy intensive industry, China’s iron/steel industry faces the challenge of energy conservation and carbon emission reduction. Energy efficiency, especially residual heat recovery is a critical issue. China is promoting a circular economy strategy in the iron/steel industry, technology upgrading and industrial symbiosis make the material and energy flows more complicated. In order to quantify the energy flows and the related residual heat recovery and carbon emission mitigation potential, this study proposes a hybrid material and energy flow analysis approach at company level. We analyze the material based energy flow routes and the transformation rules. Then, we develop an evaluation index to evaluate the specific energy consumption (SEC) and direct carbon dioxide (CO2) emissions (DCE). Furthermore, a case study is conducted in a 10 million ton/year steelmaking plant in northern China. Results verified the effectiveness of the proposed approach. According to the results, the residual heat and carbon emission is mapped out graphically. Results highlight that the case company has 4.87 GJ/tons of crude steel residual heat recovery potential, equal to 26.08% of the total energy consumption. Finally, policy implications on the ever-improvement of residual heat utilization and the future research concerns are proposed and discussed.
Co-reporter:Hong-tao JIANG, Hui-quan LI, Yi ZHANG
Journal of Fuel Chemistry and Technology (February 2007) Volume 35(Issue 1) pp:72-78
Publication Date(Web):1 February 2007
DOI:10.1016/S1872-5813(07)60012-7
Thermal distribution in catalyst bed was investigated for the fixed-bed tri-reforming of methane over Ni/Al2O3 under atmospheric pressure, 750 – 950°C, and space velocity (SV) of 2000 – 20000 h−1. The effects of the furnace temperature (tf), the space velocity, and the feed stock composition on the thermal distribution were examined. The results indicated that the temperature gradient of the catalyst bed in methane tri-reforming is smaller than that in methane partial oxidation. The temperature near the inlet of the catalyst bed (tmax) is 80°C higher than tf when the feed composition n(CH4)/n(CO2)/n(H2O)/n(O2) = 50/12.5/12.5/25 (by mol) and the space velocity SV = 20000 h−1, whereas the temperature near the outlet of the catalyst bed is close to tf. The temperature difference between the inlet and the furnace Δtmax = tmax – tf) increases with the space velocity Δtmax = 30°C at 2000 h−1, Δtmax = 80°C at 20000 h−1). No distinct hot spot is observed near the catalyst bed inlet when there is no oxygen in feed. Under specific condition, the lowest temperature in the catalyst bed (tmin) is about 30 – 40°C lower than tf. According to the thermal distribution, the catalyst bed can then be divided into three zones: oxygen adequate zone, oxygen inadequate zone, and oxygen absent zone. Methane reforming proceeds in the first and second zones, while methane combustion proceeds only in the first zone and partial oxidation of methane proceeds only in the second zone.
Co-reporter:Yan CAO, Jun ZHANG, Jiasong HE, Huiquan LI, Yi ZHANG
Chinese Journal of Chemical Engineering (2010) Volume 18(Issue 3) pp:515-522
Publication Date(Web):1 January 2010
DOI:10.1016/S1004-9541(10)60252-2
At relatively high cellulose mass concentrations (8%, 10%, and 12%), homogeneous acetylation of cellulose was carried out in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AmimCl). Without using any catalyst, cellulose acetates (CAs) with the degree of substitution (DS) in a range from 0.4 to 3.0 were synthesized in one-step. The effects of reaction time, temperature and molar ratio of acetic anhydride/anhydroglucose unit (AGU) in cellulose on DS value of CAs were investigated. The synthesized CAs were characterized by means of FT-IR, NMR, and solubility, mechanical and thermal tests. After the acetylation, the used ionic liquid AmimCl was easily recycled and reused. This study shows the potential of the homogeneous acetylation of cellulose at relatively high concentrations in ionic liquids in future industrial applications.
Co-reporter:Liguo Wang, Huiquan Li, Shumin Xin, Peng He, Yan Cao, Fengjiao Li, Xinjuan Hou
Applied Catalysis A: General (10 February 2014) Volume 471() pp:
Publication Date(Web):10 February 2014
DOI:10.1016/j.apcata.2013.11.031
•The DEC synthesis from CO2, EO and ethanol was attempted for the first time.•KI/EtONa as binary catalyst system exhibited higher catalytic performance.•This strategy can be successively expanded to terminal epoxides.•This method exhibited promising applications on an industrial scale.The synthesis of diethyl carbonate (DEC) directly from carbon dioxide, ethylene oxide (EO), and ethanol via one-pot reaction is reported for the first time. The effects of catalyst species and reaction variables on the synthetic performance of DEC were systematically studied. The integration of easily available KI and sodium ethoxide as homogeneous binary catalyst system was found to be very active for the one-pot reaction, and 63.6% of the DEC yield could be achieved under relatively mild reaction conditions (443 K, 3 MPa CO2 initial pressure, 2 h). The byproduct of 2-ethoxyethanol, which is predominantly formed via alcoholysis of EO by ethanol through ring-opening reaction, was produced with small amount (<5%) under optimized conditions. Additionally, the thermodynamic evaluation reveals that the standard molar enthalpy of one-pot reaction is exothermic (ΔrHmθ=−19.70kcal/mol<0). In comparison with the direct synthesis of DEC from CO2 and ethanol, the involvement of EO facilitates the formation of DEC, simultaneously with glycol produced. This strategy could also be successfully expanded to terminal epoxide substrates. Furthermore, a possible mechanism of the reaction was proposed on the basis of experimental results. This method provides a highly effective way to produce DEC via directly chemical utilization of CO2 and shows promising application in the manufacture of diethyl carbonate on an industrial scale.Download high-res image (134KB)Download full-size image
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