Ethylene glycol from formaldehyde

Ethylene glycol could also be obtained directly from ethylene by two methods, the Oxirane acetoxylation and the Teijin oxychlorination processes. The production of ethylene glycol from formaldehyde and carbon monoxide is noted in Chapter 5. 

The Electrosynthesis Company has piloted a second-generation hydrodimerization process to produce ethylene glycol from formaldehyde [144] (Scheme 15). 

In the manufacture of ethylene glycol from formaldehyde, glycolic acid is formed as an intermediate ... 

The DuPont process (the oldest syngas process to produce ethylene glycol) reacts formaldehyde with CO in the presence of a strong mineral acid. The intermediate is glycolic acid, which is esterified with methanol. The ester is then hydrogenated to ethylene glycol and methanol, which is recovered. The net reaction from either process could he represented as ... 

Dioxolane is available most conveniently from the peroxide transfer reaction discussed in Section 4.30.3.1.4, while 1,3-dioxolane may be prepared from ethylene glycol and formaldehyde using any acidic catalyst described in Section 4.30.3.1.3. The preparation of... 

In addition to the olefin hydroformylation, the hydroformylation of formaldehyde has become particularly interesting since it provides access to ethylene glycol from syngas without involving ethylene. The hydroformylation of formaldehyde, normally employed as polymer (paraformaldehyde), yields glycolaldehyde... 

Obtained by the cationic polymerization of 1,3-dioxolan, 2-methyl-l,3-dioxolan, 4-tnethyl-l,3-dioxolan, 2,2 -dietl5fl-l,3-dioxolan. Or it can be obtained from the polycondensation of ethylene glycol and formaldehyde. 

Formaldehyde reacts with syn gas (CO,H2) to produce added value products. Ethylene glycol (EG) may be produced in a two-stage process or the intermediate, glycolaldehyde, isolated from the first stage (65) ... 

An early source of glycols was from hydrogenation of sugars obtained from formaldehyde condensation (18,19). Selectivities to ethylene glycol were low with a number of other glycols and polyols produced. Biomass continues to be evaluated as a feedstock for glycol production (20). 

Diol Components. Ethylene glycol (ethane 1,2-diol) is made from ethylene by direct air oxidation to ethylene oxide and ring opening with water to give 1,2-diol (40) (see Glycols). Butane-1,4-diol is stiU made by the Reppe process acetylene reacts with formaldehyde in the presence of catalyst to give 2-butyne-l,4-diol which is hydrogenated to butanediol (see Acetylene-DERIVED chemicals). The ethynylation step depends on a special cuprous... 

Miscellaneous Resins. Much less important than the melamine—formaldehyde and urea—formaldehyde resins are the methylo1 carbamates. They are urea derivatives since they are made from urea and an alcohol (R can vary from methyl to a monoalkyl ether of ethylene glycol). 

Other routes have been tried starting from formaldehyde or paraformaldehyde. One process reacts formaldehyde with carhon monoxide and H2 (hydroformylation) at approximately 4,000 psi and 110°C using a rhodium triphenyl phosphine catalyst with the intermediate formation of glycolaldehyde. Glycolaldehyde is then reduced to ethylene glycol ... 

Also, 1,3-dioxolane was obtained from the reaction of ethylene glycol (EG) and aqueous formaldehyde in high yield using an ion-exchange resin catalyst. In a batch mode of operation, with 50% excess EG, the conversion of formaldehyde is limited to 50% due to equilibrium limitation, whereas in batch reactive distillation, formaldehyde conversion greater than 99%... 

Removal of formaldehyde from aqueous 2-butyne-l,4-diol, or a similar solution, which is relevant in the subsequent manufacture of c -2-butene-l,4-diol, by batch reactive distillation with methanol or ethylene glycol in the presence of Indion 130 as catalyst has also been reported 98% conversion of formaldehyde was obtained by reactive distillation with 7 times the stoichiometric quantity of methanol, compared to 15% conversion obtained in a closed system (Kolah and Sharma, 1995). 

Figure 5.6 Alcohols, aldehydes, ketones and acids 15, ethylene glycol 16, vinyl alcohol 17, acetaldehyde 18, formaldehyde 19, glyoxal 20, propionaldehyde 21, propionaldehyde 22, acetone 23, ketene 24, formic acid 25, acetic acid 26, methyl formate. (Reproduced from Guillemin et at. 2004 by permission of Elsevier)...

Ethylene glycol (the potential market is said to be of the order of 10 billion kilos per annum [104b]) is made by electrodimerisation of formaldehyde from... 

Hydroformylation of formaldehyde to give glycolaldehyde is an attractive route from syn-gas toward ethylene glycol. The reaction is catalysed by rhodium arylphosphine complexes [39] but clearly phosphine decomposition is... 

Together, antifreeze, PET, and polyester polymers account for about 98% of the ethylene glycol produced in the United States. It is also used sometimes as a deicer for aircraft surfaces. The two hydroxyl groups in the EG molecule also make EG suitable for the manufacture of surfactants and in latex paints. Other applications include hydraulic brake fluid, the manufacture of alkyd resins for surface coatings, and stabilizers for water dispersions of urea-formaldehyde and melamine-formaldehyde The hygroscopic properties (absorbs moisture from the air) make EG useful as a humectant for textile fibers, paper, leather, and adhesives treatment. 

Beckett and Hua (2000) investigated the sonolytic decomposition of 1,4-dioxane in aqueous solution at 25 °C at discrete ultrasonic frequencies. They found that the highest first-order decomposition rate occurred at 358 kHz followed by 618, 1,071, and 205 kHz. At 358 kHz, 96% of the initial 1,4-dioxane concentration was decomposed after 2 h and the pH of the solution decreased to 3.75 from 7.50. Major decomposition intermediates were ethylene glycol diformate, methoxyacetic acid, formaldehyde, glycolic acid, and formic acid. 

The concept of a (bound) formaldehyde intermediate in CO hydrogenation is supported by the work of Feder and Rathke (36) and Fahey (43). Experiments under H2/CO pressure at 182-220°C showed that paraformaldehyde and trioxane (which depolymerize to formaldehyde at reaction temperatures) are converted by the cobalt catalyst to the same products as those formed from H2/CO alone. The rate of product formation is faster than in comparable H2/CO-only experiments, and product distributions are different, apparently because secondary reactions are now less competitive. However, Rathke and Feder note that the formate/alcohol ratio is similar to that found in H2/CO-only reactions (36). Roth and Orchin have reported that monomeric formaldehyde reacts with HCo(CO)4 under 1 atm of CO at 0°C to form glycolaldehyde, an ethylene glycol precursor (75). The postulated steps in this process are shown in (19)—(21), in which complexes not observed but... 

Other work has shown that cobalt complexes under H2/CO pressure and at higher temperatures can catalytically convert formaldehyde to glycolalde-hyde (76) or ethylene glycol (77-79) methanol is observed as a product as well. It has therefore been well demonstrated that formaldehyde can be converted by cobalt catalysts to the same products observed from CO reduction. 

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