Synthesis of polyoxymethylene dimethyl ethers from methanol and trioxymethylene with molecular sieves as catalysts

Zhao, Qi; Wang, Hui; Qin, Zhangfeng; Wu, Zhiwei; Wu, Jianbing; Fan, Weibin; Wang, Jianguo

doi:10.1016/s1872-5813(12)60003-6

Cited by 78 publications

(60 citation statements)

References 10 publications

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“…2 There is large number of articles (e.g. [7][8][9][10][11][12][13][14][15][16][17][18] ) and patents from China concerning OME, as China is the largest coal producer in the world and is seeking for an option to produce liquid fuels from coal. Synthesis gas may however also be produced from renewable feedstocks.…”

Section: Introductionmentioning

confidence: 99%

Chemical Equilibrium of the Synthesis of Poly(oxymethylene) Dimethyl Ethers from Formaldehyde and Methanol in Aqueous Solutions

Schmitz

Homberg

Berje

et al. 2015

Ind. Eng. Chem. Res.

113

176

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Poly(oxymethylene) dimethyl ethers (OME) reduce the soot formation during the combustion process, when added to diesel fuels. OME are a Gas-to-Liquid (GtL) option as they can be produced via methanol from natural gas or renewable feedstocks. This work deals with the synthesis of OME from the educts formaldehyde and methanol in aqueous solutions. The studied mixtures are complex reacting systems in which besides OME, also poly(oxymethylene) glycols and poly(oxymethylene) hemiformals are present. The chemical equilibrium of the OME formation is studied in a stirred batch reactor varying in the educts' overall ratio of formaldehyde to methanol and the amount of water and varying the temperature between 333.15 K and 378.15 K. A mole fraction-based, as well as an activity-based model of the chemical equilibrium of the OME formation are developed, which explicitly account for the formation of poly(oxymethylene) glycols and poly(oxymethylene) hemiformals. Information on the latter reactions from literature are confirmed by NMR experiments in the present work.

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Section: Introductionmentioning

confidence: 99%

Chemical Equilibrium of the Synthesis of Poly(oxymethylene) Dimethyl Ethers from Formaldehyde and Methanol in Aqueous Solutions

Schmitz

Homberg

Berje

et al. 2015

Ind. Eng. Chem. Res.

113

176

View full text Add to dashboard Cite

show abstract

“…The addition of DMMx to diesel oil can greatly improve the combustion and reduce particular matter emissions of diesel engines. In indusry, DMM x is mainly produced via condensation of methanol and trioxymethylene over acidity catalysts [2], but this synthesis technology has the problems of high energy consumption, high investment and high operation cost. Utilizing oxidation of DME to synthesize DMM x is one of the most attractive green routes for the synthesis of clean fuel additives with a short process, low CO 2 emissions and high energy efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…It can be seen in Table 1 that no CO x is formed in the reaction of DME to DMM and DMM 2 when CNTs are used as support along with an optimum amount of PW 12 introduction under the conditions of 513 K and 1800 h´1. This may be due to the special adsorption capacity and excellent conductivity of CNTs.…”

Section: Introductionmentioning

confidence: 99%

Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst

et al. 2016

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Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs) were selected as support to prepare a Re-based catalyst for dimethyl ether (DME) direct oxidation to polyoxymethylene dimethyl ethers (DMM x ). The catalyst performance was tested in a continuous flow type fixed-bed reactor. H 3 PW 12 O 40 (PW 12 ) was used to modify Re/CNTs to improve its activity and selectivity. The effects of PW 12 content, reaction temperature, gas hourly space velocity (GHSV) and reaction time on DME oxidation to DMM x were investigated. The results showed that modification of CNT-supported Re with 30% PW 12 significantly increased the selectivity of DMM and DMM 2 up to 59.0% from 6.6% with a DME conversion of 8.9%; besides that, there was no CO x production observed in the reaction under the optimum conditions of 513 K and 1800 h´1. The techniques of XRD, BET, NH 3 -TPD, H 2 -TPR, XPS, TEM and SEM were used to characterize the structure, surface properties and morphology of the catalysts. The optimum amount of weak acid sites and redox sites promotes the synthesis of DMM and DMM 2 from DME direct oxidation.

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“…As a new type of oxygenated fuel, polyoxymethylene dimethyl ethers (PODE n ) are effective at reducing diesel PM emissions because PODE n have no C-C bonds in their molecular structure, a substantial carbon/hydrogen ratio and high oxygen content with a large cetane number (Burger et al, 2010;Zhao et al, 2011;Zhao et al, 2013;Yang et al, 2015). PODE n can be synthesized through a polymerization reaction using methanol as a raw material, and many crude materials can be used to produce them, including coal and biomass.…”

Section: Introductionmentioning

confidence: 99%

Pyrolysis Characteristic Analysis of Particulate Matter from Diesel Engine Run on Diesel/Polyoxymethylene Dimethyl Ethers Blends Based on Nanostructure and Thermogravimetry

Yang

Wang

et al. 2016

Aerosol Air Qual. Res.

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This paper focuses on the nanostructural and pyrolysis characteristics of particulate matter (PM) emitted from a diesel engine fueled by three diesel/polyoxymethylene dimethyl ethers (PODE n ) blends. PM was collected using a metal filter from the exhaust manifold. The collected PM samples were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). SEM and TEM analysis showed that PM generated by the 20%-PODE n blend was looser and had a smaller average diameter than that emitted when a lower proportion of PODE n was used. Additionally, fringe length was reduced, and separation distance and tortuosity were increased, when the 20%-PODE n blend was used instead of the other blends. These changes improved the oxidation reactivity of the PM. TGA demonstrated that the PM pyrolysis process was divided into low temperature (characterized by moisture and volatile components) and high temperature (the combustion of solid carbon) stages. When the blending ratio was increased, the moisture and volatile components of the PM showed no obvious change, but the ignition temperature and activation energy were reduced. Additionally, the pyrolysis performance was enhanced; the maximum weight loss rate was higher; the combustion and burnout characteristic indices were higher; and the combustion efficiency of the PM was improved. These results show that the use of diesel blended with oxygenated fuel (PODE n ) affects the nanostructure and pyrolysis of PM, and this PM is easier to oxidize and advantageous for diesel particulate filter regeneration.

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Synthesis of polyoxymethylene dimethyl ethers from methanol and trioxymethylene with molecular sieves as catalysts

Cited by 78 publications

References 10 publications

Chemical Equilibrium of the Synthesis of Poly(oxymethylene) Dimethyl Ethers from Formaldehyde and Methanol in Aqueous Solutions

Chemical Equilibrium of the Synthesis of Poly(oxymethylene) Dimethyl Ethers from Formaldehyde and Methanol in Aqueous Solutions

Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst

Pyrolysis Characteristic Analysis of Particulate Matter from Diesel Engine Run on Diesel/Polyoxymethylene Dimethyl Ethers Blends Based on Nanostructure and Thermogravimetry

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