Formaldehyde from ethylene

MMA and MAA can be produced from ethylene [74-85-1/ as a feedstock via propanol, propionic acid, or methyl propionate as intermediates. Propanal may be prepared by hydroformylation of ethylene over cobalt or rhodium catalysts. The propanal then reacts in the Hquid phase with formaldehyde in the... 

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... 

CycHc sulfates can be prepared by a vahety of methods. Ethylene sulfate is obtained in low yield from ethylene oxide and sulfur thoxide (100). Methylene sulfate is produced from formaldehyde and sulfur thoxide (101). 

Key intermediates in the industrial preparation of both nicotinamide and nicotinic acid are alkyl pyridines (Fig. 1). 2-Meth5l-5-ethylpyridine (6) is prepared in ahquid-phase process from acetaldehyde. Also, a synthesis starting from ethylene has been reported. Alternatively, 3-methylpyridine (7) can be used as starting material for the synthesis of nicotinamide and nicotinic acid and it is derived industrially from acetaldehyde, formaldehyde (qv), and ammonia. Pyridine is the principal product from this route and 3-methylpyridine is obtained as a by-product. Despite this and largely due to the large amount of pyridine produced by this technology, the majority of the 3-methylpyridine feedstock is prepared in this fashion. 

Ethylene Oxide Purification. The main impurities ia ethylene oxide are water, carbon dioxide, and both acetaldehyde and formaldehyde. Water and carbon dioxide are removed by distillation ia columns containing only rectifying or stripping sections. Aldehydes are separated from ethylene... 

The Grignard reagent from 2-thenyl chloride can be obtained by the use of the "cyclic reactor.However, rearrangement occurs in its reaction with carbon dioxide, ethyl chlorocarbonate, acetyl chloride, formaldehyde, and ethylene oxide to 3-substituted 2-methylthio-phenes, Only in the case of carbon dioxide has the normal product also been isolated. 

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. 

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). 

The addition of Grignard reagents to aldehydes, ketones, and esters is the basis for the synthesis of a wide variety of alcohols, and several examples are given in Scheme 7.3. Primary alcohols can be made from formaldehyde (Entry 1) or, with addition of two carbons, from ethylene oxide (Entry 2). Secondary alcohols are obtained from aldehydes (Entries 3 to 6) or formate esters (Entry 7). Tertiary alcohols can be made from esters (Entries 8 and 9) or ketones (Entry 10). Lactones give diols (Entry 11). Aldehydes can be prepared from trialkyl orthoformate esters (Entries 12 and 13). Ketones can be made from nitriles (Entries 14 and 15), pyridine-2-thiol esters (Entry 16), N-methoxy-A-methyl carboxamides (Entries 17 and 18), or anhydrides (Entry 19). Carboxylic acids are available by reaction with C02 (Entries 20 to 22). Amines can be prepared from imines (Entry 23). Two-step procedures that involve formation and dehydration of alcohols provide routes to certain alkenes (Entries 24 and 25). 

For oxetane formation from formaldehyde and ethylene, we should consider the following four transition states and intermediates for the reaction<181) ... 

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... 

BASF led the development of a route based on ethylene and synthesis gas. Its four step process begins with the production of propionaldehyde from ethylene, CO, and H2 using a proprietary catalyst mixture that they aren t telling anything about. Reaction with formaldehyde gives methacrolein. The last two steps are the same as above—oxidation with air yields the MAA subsequent reaction with methanol yields MMA. 

Ethylene-Based (C-2> Routes. MMA and MAA can be produced from ethylene as a feedstock via propanol, propionic acid, or melhyl propionate as intermediates. Propanal may be prepared by hydrofonnylalion of ethylene over cobalt or rhodium catalysts. The propanal then reads in the liquid phase with formaldehyde in the presence of a secondary amine and. optionally, a carboxylic acid. The reaction presumably proceeds via a Mannich base intermediate which is cracked to yield methacrolcin. Alternatively, a gas-phase, crossed akin I reaelion with formaldehyde cataly zed by molecular sieves [Pg.988]

The activation of methane [1] is also included as one of the most desired yet not technically viable reactions. Abundant amounts of methane occur with crude oil and as gas in remote locations it is also produced in large quantities during hydrocarbon processing. A large fraction of this methane is flared, because economical use or transportation is not possible. This gas and the abundant resources of methane gas hydrates would make a very suitable feedstock for higher hydrocarbons, if its activation to produce molecules other than synthesis gas were feasible. Despite enormous fundamental and practical efforts [1-5], no applicable method has yet been found for creation of ethylene, methanol, or formaldehyde from methane. 

Supported CrC>3 catalysts, referred to as Phillips catalysts, are important industrial catalysts and are employed in high-density polyethylene production. Phillips catalysts polymerise ethylene with an induction period, which has been ascribed to the slow reduction of Cr(VI) by the monomer and to the displacement of oxidation products (mainly formaldehyde) from the catalytic species [226]. The prereduction of the catalyst with the use of H2 or CO enables the induction period to be eliminated. Active sites thus formed involve surface low-valence Cr(II) and Cr(III) centres, which can appear as mononuclear (formed from chromate species) and binuclear (formed from dichromate species) [227-232],... 

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... 

Reaction of the bis Bunte salt (280), prepared from ethylene dibromide and sodium thiosulfate, with formaldehyde in the presence of hydrogen chloride produces the 1,3-dithiolane (4) (30JCS12). 

Geigy A one-stage process for making ethylenediamine tetra-acetic acid (EDTA) from ethylene-diamine, hydrogen cyanide, and formaldehyde. 

Acrolein and condensable by-products, mainly acrylic acid plus some acetic acid and acetaldehyde, are separated from nitrogen and carbon oxides in a water absorber. However in most industrial plants the product is not isolated for sale, but instead the acrolein-rich effluent is transferred to a second-stage reactor for oxidation to acrylic acid. In fact the volume of acrylic acid production ca. 4.2 Mt/a worldwide) is an order of magnitude larger than that of commercial acrolein. The propylene oxidation has supplanted earlier acrylic acid processes based on other feedstocks, such as the Reppe synthesis from acetylene, the ketene process from acetic acid and formaldehyde, or the hydrolysis of acrylonitrile or of ethylene cyanohydrin (from ethylene oxide). In addition to the (preferred) stepwise process, via acrolein (Equation 30), a... 

Other routes to MMA start from ethylene, propylene or propyne and involve metal catalysis at some stage of multi-step transformations for example by the hydroformylation of ethylene to intermediate propionaldehyde, oxidation to propionic acid, followed by condensation with formaldehyde. The Pd-catalyzed carbonylation of propyne to MMA is a further method. However only the ethylene route has found some industrial application (see Chapter 4, Section 4.3.1). 

Ru3(CO)i2/Talkylbenzimidazoles showed high selectivity for ethylene glycol [13]. A mechanistic study of this reaction showed that RuH2(CO)3(l-methylbenzimid-azole) is formed, and this complex is considered to be the active species. 1-Methyl-benzimidazole enhances both the rate of the formation of formaldehyde from syngas and the rate of the hydroformylation of formaldehyde [14]. 

The conclusions from the correlation diagrams have been nicely confirmed by early ab initio calculations for the carbon-oxygen attack of formaldehyde on ethylene (Salem, 1974) and by more recent calculations on the same model reaction considering both modes of attack. (Palmer et al., 1994). 

Figure 7.38. Photocycloaddition of formaldehyde and ethylene. Schematic representation of the surfaces involved in the carbon-oxygen attack as a function of the C,0 distance Rqq and the dihedral angle

The photolysis of dimethyl and diethyl ethers in the gas phase was first studied by Harrison and Lake (172) using a hydrogen discharge lamp. They reported the formation of formaldehyde from dimethyl ether, and ethylene, acetaldehyde, and formaldehyde from diethyl ether. 

---