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Chinese Journal of Chemical Engineering 2022年第6期35卷 161-172页

作者： Xiangjun Li Shujun Li Xiaoping Wang Muhammad Asif Nawaz Dianhua Liu State Key Lab of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

The synthesis of polyoxymethylene dimethyl ethers as an ideal diesel fuel additive is the current hot topic of modern petrochemical industry for their expedient properties in mitigating air pollutants emission during *** this work,a series of spherical sulfated zirconia catalysts were prepared by a one-pot hydrothermal method assisted with surfactant cetyltrimethylammonium bromide(CTAB).The prepared sulfated zirconia catalysts were used to catalyze PODEn synthesis from methanol and formaldehyde *** characterization(XRD,BET,SEM,TGA,NH_(3)-TPD,FTIR,and Py-IR)were employed to elaborate the structure–activity relationship of the studied catalytic *** results demonstrated that S/Zr molar ratio in precursor solution played an effective role on catalyst morphology and acidic properties,where the weak Brønsted acid sites and strong Lewis acid sites were favorable to the conversion of methanol and formation of long-chain PODEn,*** reaction parameters such as catalyst amount,molar ratio of FA/MeOH,reaction time,temperature and pressure were *** speculated reaction pathway for PODEn synthesis was proposed based on the synergy of Brønsted and Lewis acid sites,which suggested that Brønsted and Lewis acid sites might be advantageous to the activation of polyoxymethylene hemiformals[CH_(3)(OCH_(2))_(n)OH]and methylene glycol(HOCH_(2)OH),respectively.

关键词： polyoxymethylene dimethyl ethers Spherical sulfated zirconia Methanol Formaldehyde Reaction pathway Synergistic effect

Controllable synthesis of polyoxymethylene dimethyl ethers by ionic liquids encapsulated in mesoporous SBA-16

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Chinese Journal of Chemical Engineering 2021年第4期34卷 175-182页

作者： Chaofeng Zhang Tonglu Zhang Jing Zhang Jiandong Zhang Ruifeng Li College of Biomedical Engineering Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China

The promising combustion and emission properties of polyoxymethylene dimethyl ethers(PODEn)are of significant ***,the synthesis of PODEn products with desired chain lengths is still a problem facing synthetic ***,a series of unique IL@SBA16Cx solid catalysts are prepared by encapsulation of ionic liquids(ILs)within the nanocage of SBA16 through a silylation *** structure of the encapsulated catalyst was characterized by UVvis spectra,Fourier transform infrared(FTIR),N2 adsorptiondesorption isotherms,Powder Xray diffraction(XRD),Transmission electron microscopy(TEM)and Elemental *** encapsulated catalysts show similar catalytic activity to the homogeneous counterparts and display higher selectivity to the targeted PODE35 products than their homogeneous counterparts in the synthesis of PODEn from methanol(MeOH)and trioxymethylene(TOM).The encapsulated catalysts exhibit a superior PODE35 selectivity and could be the promising catalysts for PODEn synthetic reaction.

关键词： SBA-16 polyoxymethylene dimethyl ethers Ionic liquids Heterogeneous catalyst Diesel fuel additives

Chemical equilibrium controlled synthesis of polyoxymethylene dimethyl ethers over sulfated titania

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Journal of Energy Chemistry 2015年第2期24卷 239-244页

作者： Huaju Li Huanling Song Feng Zhao Liwei Chen Chungu Xia Laboratory for Nano-Catalytic Material & Technology Division of Advanced Nano?materials Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of Sciences State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences i-Lab Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences

The chemical equilibrium and reaction kinetic behavior in the synthesis of polyoxymethylene dimethyl ethers （DMMn） were investigated over sulfated titania in order to reveal the decisive factor controlling the reaction. The results showed that the molar ratio of adjacent DMMn products in equilibrium solution had the same value, which depended absolutely on the reaction temperature. Meanwhile, the reactions had the same DMMn products distributions under varied reaction conditions. The equilibrium constants of the related step-wise reactions for DMMn formation were equal, which were calculated based on the bulk compositions of the reaction solution. And thus, the selectivity to DMMn was mainly controlled by the chemical equilibrium, i.e., thermodynamic control. In brief, the present results provide some guidance for future synthesis of DMMn.

关键词： polyoxymethylene dimethyl ethers sulfated titania chemical equilibrium reaction kinetic molar ratio

Optical investigation on polyoxymethylene dimethyl ethers spray flame at different oxygen levels in a constant volume vessel

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Science China(Technological Sciences) 2021年第8期64卷 1611-1623页

作者： ZHENG ZunQing LIU Wei LIU HaiFeng FENG Lei CUI YanQing ZHANG Shuo YAO MingFa State Key Laboratory of Engines Tianjin UniversityTianjin300072China

In this paper,high-speed imaging and spectrometry diagnostics were used to study the spray flame structures and emission spectra of polyoxymethylene dimethyl ethers(PODE)in an optical constant volume *** effects of oxygen volume fraction(15%to 80%)on some typical combustion characteristics such as spatially integrated natural intensity,flame propagation speed,lift-off length and the distribution of flame emission spectra were *** results show that the PODE spray flame mainly exhibits blue chemiluminescence,which is different from the diesel yellow diffusion flame dominated by soot *** the oxygen concentration increases,the flame natural luminosity and propagation speed increases,the position of lift-off region and flame tip move towards the injector nozzle,and the flame width becomes *** to the spectral results,the blue chemiluminescence generated by carbon monoxide oxidation dominates the PODE flame luminescence,suggesting that no soot is *** increase in oxygen concentration leads to enlarged intensity and gradient of PODE flame *** summary,the combination of PODE and oxygen-enriched combustion shows no soot formation and promotes the oxidation of carbon monoxide and unburned *** study can provide more insights into PODE spray combustion,and offer guidelines for achieving efficient and clean combustion.

关键词： polyoxymethylene dimethyl ethers oxygen enrichment spray flame constant volume vessel optical diagnostics smokeless combustion