110-88-3Relevant articles and documents
The salt effect on the yields of trioxane in reaction solution and in distillate
Yin, Liuyi,Hu, Yufeng,Zhang, Xianming,Qi, Jianguang,Ma, Weiting
, p. 37697 - 37702 (2015)
Batch reaction experiments were performed to investigate the salt effect on the yield of trioxane in the reaction solution. The salts considered include NaHSO4, Na2SO4, NaH2PO4, Na2HPO4, KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3. The effects of the anionic structure and the cation charge density on the yield of trioxane in the reaction solution were elucidated and the mechanisms that govern such effects were established. It is shown that the first four salts exerted a negative effect on the yield of trioxane in the reaction solution and such an effect increased progressively from left to right. This trend is due to the formation of NaHSO4, H3PO4, or (H3PO4 and NaH2PO4), which decreased the concentration of H+ in the solution. The latter six salts showed a positive effect on the yield of trioxane in the reaction solution. The salt effect paralleled the ability of the salt to decrease the water activity of the reaction solution and followed the order KCl 2 2 3. Continuous production experiments were performed to investigate the salt effect on the concentration of trioxane in the distillate. The salts considered were KCl, NaCl, LiCl, ZnCl2, MgCl2, and FeCl3, and the salt effect increased progressively from left to right. Such an effect was shown to be determined by the ability of the salt to increase the yield of trioxane in the reaction solution and to increase the relative volatilities of trioxane and water and of trioxane and oligomers.
Influence of Silanol Defects of ZSM-5 Zeolites on Trioxane Synthesis from Formaldehyde
Ye, Yuling,Yao, Mengqin,Chen, Honglin,Zhang, Xiaoming
, p. 1445 - 1453 (2020)
Abstract: The silanol defects in ZSM-5 zeolite have been recognized as an important factor in catalytic activity. Here, ZSM-5 zeolites with different amounts of silanol defect sites were synthesized from synthetic gels containing fluoride medium and were applied as catalysts for trioxane synthesis. The results of XRD, SEM, NH3-TPD, Py-IR, OH-IR, 27Al MAS NMR, 1H MAS NMR, and TG indicated that all ZSM-5 zeolites showed similar crystal size, relative crystallinity, porosity, and the number of Br?nsted acid sites. However, the silanol defects reduced obviously and the number of Lewis acid sites reduced correspondingly when a little NH4F was added in the synthesis gels and both of them decreased slightly with increase of F/Si ratio. Compared with ZSM-5 zeolite prepared in hydroxide medium, ZSM-5 zeolite prepared in fluoride medium displayed higher selectivity to trioxane and increased gradually with increase of F/Si ratio. Moreover, the lifetime of ZSM-5 zeolite prepared in fluoride medium was longer than that of prepared in hydroxide medium. Thus, ZSM-5 zeolite prepared in fluoride medium which contained the few silanol defects and low Lewis acid sites is an efficient catalyst for trioxane synthesis. Graphic Abstract: [Figure not available: see fulltext.]
Study of trioxane production process with super- or subcritical fluid as solvent and extractant
Tanaka, Michio,Ogino, Kenji
, p. 1927 - 1932 (2006)
A super- or subcritical fluid was used as a reaction solvent for nonaqueous trioxane synthesis instead of common organic solvents. The generation of trioxane from paraformaldehyde was observed in the presence of the catalyst when carbon dioxide reached a supercritical region, suggesting that the supercritical carbon dioxide acted as the reaction solvent. In the case of Freon 12, the trioxane was effectively produced even in a subcritical state. Copyright Taylor & Francis Group, LLC.
Fixation and spontaneous dehydrogenation of methanol on a triruthenium-iridium framework: Synthesis and structure of the cluster anion [HRu3Ir(CO)12(OMe)]-
Haak, Susanne,Neels, Antonia,Stckli-Evans, Helen,Suess-Fink, Georg,Thomas, Christophe M.
, p. 1959 - 1960 (1999)
The anionic mixed-metal cluster [RU3Ir(CO)13]- 1, found to be catalytically active in the carbonylation of methanol, reacts with methanol at 70°C to give, with O-H activation of the substrate, the cluster anion [HRu3Ir(CO)12(OMe)]- 2, which upon prolonged reaction loses formaldehyde to give the cluster anion [H2RU3Ir(CO)12]- 3; both anions 2 and 3 crystallise together as the double-salt [N(PPh3)2]2[HRu3Ir(CO)12(OMe)][H2Ru3Ir(CO)12] the single-crystal X-ray structure analysis of which reveals a butterfly Ru3Ir skeleton for 2 and a tetrahedral Ru3Ir skeleton for 3.
Selective Reduction of CO2 to CH4 by Tandem Hydrosilylation with Mixed Al/B Catalysts
Chen, Jiawei,Falivene, Laura,Caporaso, Lucia,Cavallo, Luigi,Chen, Eugene Y.-X.
, p. 5321 - 5333 (2016)
This contribution reports the first example of highly selective reduction of CO2 into CH4 via tandem hydrosilylation with mixed main-group organo-Lewis acid (LA) catalysts [Al(C6F5)3 + B(C6F5)3] {[Al] + [B]}. As shown by this comprehensive experimental and computational study, in this unique tandem catalytic process, [Al] effectively mediates the first step of the overall reduction cycle, namely the fixation of CO2 into HCOOSiEt3 (1) via the LA-mediated C - O activation, while [B] is incapable of promoting the same transformation. On the other hand, [B] is shown to be an excellent catalyst for the subsequent reduction steps 2-4, namely the hydrosilylation of the more basic intermediates [1 to H2C(OSiEt3)2 (2) to H3COSiEt3 (3) and finally to CH4] through the frustrated Lewis pair (FLP)-type Si-H activation. Hence, with the required combination of [Al] and [B], a highly selective hydrosilylative reduction of CO2 system has been developed, achieving high CH4 production yield up to 94%. The remarkably different catalytic behaviors between [Al] and [B] are attributed to the higher overall Lewis acidity of [Al] derived from two conflicting factors (electronic and steric effects), which renders the higher tendency of [Al] to form stable [Al]-substrate (intermediate) adducts with CO2 as well as subsequent intermediates 1, 2, and 3. Overall, the roles of [Al] and [B] are not only complementary but also synergistic in the total reduction of CO2, which render both [Al]-mediated first reduction step and [B]-mediated subsequent steps catalytic.
Controlling the Product Platform of Carbon Dioxide Reduction: Adaptive Catalytic Hydrosilylation of CO2 Using a Molecular Cobalt(II) Triazine Complex
Chatterjee, Basujit,Cramer, Hanna H.,Leitner, Walter,Werlé, Christophe,Weyhermüller, Thomas
supporting information, p. 15674 - 15681 (2020/06/08)
The catalytic reduction of carbon dioxide (CO2) is considered a major pillar of future sustainable energy systems and chemical industries based on renewable energy and raw materials. Typically, catalysts and catalytic systems are transforming CO2 preferentially or even exclusively to one of the possible reduction levels and are then optimized for this specific product. Here, we report a cobalt-based catalytic system that enables the adaptive and highly selective transformation of carbon dioxide individually to either the formic acid, the formaldehyde, or the methanol level, demonstrating the possibility of molecular control over the desired product platform.
Methanesulfinylation of Benzyl Halides with Dimethyl Sulfoxide
Fu, Duo,Dong, Jun,Du, Hongguang,Xu, Jiaxi
, p. 2752 - 2758 (2020/01/31)
A phenyltrimethylammonium tribromide-mediated nucleophilic substitution/oxygen transformation reaction of benzyl halides with DMSO has been developed. In this transition-metal-free reaction, DMSO acts as not only a solvent but also a "S(O)Me" source, thus providing a convenient method for the efficient and direct synthesis of various benzyl methyl sulfoxides.
METHOD OF PRODUCING TRIOXANE
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Paragraph 0039-0041, (2016/04/09)
Disclosed is a method of producing trioxane, including: (A) preparing trioxane from a high-concentration formaldehyde aqueous solution in the presence of an acid catalyst; (B) distilling a mixture including trioxane; (C) liquefying the distilled gas mixture; (D) mixing the liquefied liquid mixture with an extraction solvent and separating the mixture into an aqueous phase and a solvent phase; (E) distilling the solvent phase to give trioxane, and mixing the aqueous phase with the extraction solvent to give a mixture, which is then separated into an aqueous phase and a solvent phase; and (F) discharging the aqueous phase separated in (E) out of the system, and recirculating the solvent phase so as to be reused in (D) and (E).
Method for synthesizing trioxymethylene by cyclic reaction of formaldehyde aqueous solution catalyzed by ionic liquid
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Paragraph 0114; 0115, (2017/01/17)
The invention provides a method for synthesizing trioxymethylene by cyclic reaction of a formaldehyde aqueous solution catalyzed by ionic liquid. The method comprises the following steps: carrying out distillation reaction to the reactants formaldehyde aqueous solution and ionic liquid under atmospheric conditions at 97-102 DEG C so as to synthesize trioxymethylene; in percentage by weight, the addition amount of the formaldehyde aqueous solution is 30-80wt%, the addition amount of the ionic liquid is 0.1-6wt%, and water accounts for all the remaining percentage; and the ionic liquid is a liquid composed of anions and cations, wherein the anions are p-ClPhSO3-. The ionic liquid formed by 4-chlorobenzene sulfonate as anion is used as the catalyst of the method so as to synthesize trioxymethylene by cyclic reaction of formaldehyde; thus, the catalyst is high in catalytic activity and small in dosage; moreover, the reacted trioxymethylene is relatively high in concentration while the contents of the byproducts, including methanol, formic acid and the like, are low; and the reacted trioxymethylene is also good in selectivity.
A three-poly process for the preparation of formaldehyde
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Paragraph 0030-0033, (2017/06/13)
The invention discloses a preparation method of trioxymethylene. The method comprises the following steps: delivering a formaldehyde water solution into a reaction kettle, and reacting under the catalytic action of sulfuric acid to obtain trioxymethylene; meanwhile, connecting a liquid discharge pipeline of the reaction kettle to a feed pipeline of a formaldehyde concentrating tower A so that the liquid in the middle part of the reaction kettle is discharged into the formaldehyde concentrating tower A, and recovering formaldehyde; and distilling the liquid in the reaction kettle, and separating to obtain the trioxymethylene. The method can recover the overhigh-concentration formaldehyde solution in the trioxymethylene reaction solution, and enhances and stabilizes the balance and conversion rate of the trioxymethylene synthetic reaction. The method effectively avoids the formation of solids and residues in the trioxymethylene synthetic reaction kettle, solves the problem of blockage of the pipelines and reboiler, and prevents the trioxymethylene production equipment from corrosion. The method implements zero discharge of the trioxymethylene synthetic reaction solution, enhances the raw material utilization ratio and saves the reaction cost. The method is simple and environment-friendly, is easy to operate and control, and relieves the pressure of the sewage treatment system.
