Formaldehyde from acetylene

Butanediol. 1,4-Butanediol [110-63-4] made from formaldehyde and acetylene, is a significant market for formaldehyde representing 11% of its demand (115). It is used to produce tetrahydrofuran (THF), which is used for polyurethane elastomers y-butyrolactone, which is used to make various pyrroHdinone derivatives poly(butylene terephthalate) (PBT), which is an engineering plastic and polyurethanes. Formaldehyde growth in the acetylenic chemicals market is threatened by alternative processes to produce 1,4-butanediol not requiring formaldehyde as a raw material (140) (see Acetylene-derived chemicals). 

Ethynylation. Base-catalyzed addition of acetylene to carbonyl compounds to form -yn-ols and -yn-glycols (see Acetylene-DERIVED chemicals) is a general and versatile reaction for the production of many commercially useful products. Finely divided KOH can be used in organic solvents or Hquid ammonia. The latter system is widely used for the production of pharmaceuticals and perfumes. The primary commercial appHcation of ethynylation is in the production of 2-butyne-l,4-diol from acetylene and formaldehyde using supported copper acetyHde as catalyst in an aqueous Hquid-fiHed system. 

The monomer is prepared from acetylene, formaldehyde and ammonia via but-2-yne-1,4-diol, butane-1,4-diol, y-butyrolactone and y-pyrrolidone (Figure 17.8). 

Formaldehyde from water and acetylene from lower hydrocarbons. Gases, polar materials such as water, alcohols, aldehydes and glycols. 

The hydroformylation of acrolein cyclic acetals has received considerable attention in the recent patent literature as a route to 1,4-butanediol (76-52). This diol is a comonomer for the production of polybutylene terephthalate, an engineering thermoplastic. The standard method for its manufacture has been from acetylene and formaldehyde, as shown in Eqs. (37) and (38) ... 

Butanediol, also known as tetramethylene glycol, is produced by the hydrogenation of butynediol (made from acetylene and formaldehyde). 

The alkyne is actually available as it is easily made from acetylene and formaldehyde. Two decisions remain how do we distinguish the three alcohols in 36 and what reagent do we use for Me- in the reaction on the epoxide Protection as the cyclic acetal 40 makes epoxidation straightforward and Me2CuLi turned out to be the best reagent for opening the epoxide. We now have two of the OHs protected 42 but they are the wrong two ... 

If we put X = OMe we have a skeleton that could be made by hydration of the symmetrical acetylene 17 and the ethers put in by alkylation of the diol 18. The diol is available because it is easily made from acetylene and formaldehyde. 

The Reppe process is used to make 1,4-1 butanediol from acetylene. In this process, acetylene and formaldehyde are reacted in the presence of a copper-bismuth catalyst. The resulting intermediate, 2-butyne-l,4-diol is hydrogenated over a Raney nickel catalyst ... 

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... 

In a trickle bed reactor the gas and liquid flow (trickle) concurrently downward over a packed bed of catalyst particles. Industrial trickle beds are typically 3 to 6 m deep and up to 3 m in diameter and are filled with catalyst particles ranging irom to in. in diameter. The pores of the catalyst are filled with liquid. In petroleum refining, pressures of 34 to 100 atm and temperatures of 350 to 425°C are not uncommon. A pilot-plant trickle bed reactor might be about 1 m deep and 4 cm in diameter. Trickle beds are used in such processes as the hydrodesulfurization of heavy oil stocks, the hydrotreating of lubricating oils, and reactions such as the production of butynediol from acetylene and aqueous formaldehyde over a copper acetylide catalyst. It is on this latter type of reaction,... 

Probten 18.13 Outline a synthesis of (a) pentanedioic acid from 1,3-propanediol (available from a fmnentation of glycerol) (b) nonanedioic acid from c/s-9-octadeoe-noic acid (oleic acid, obtained from fats) (c) succinic acid from 1,4-butynedioI (available from acetylene and formaldehyde). 

In volume terms, the most important ethynylation product is butynediol. It is prepared with copper acetylide catalysis [5] from aqueous formaldehyde and acetylene (eq. (1)). Heterogeneous copper catalysts, on support materials, are most commonly used for this reaction. 

Derivation Reduction of 2-butyne-l,4-diol, by high-pressure synthesis from acetylene and formaldehyde. 

Derivation From acetylene and formaldehyde by high-pressure synthesis. 

Derivation High-pressure synthesis from acetylene and formaldehyde. 

Desulfurization of petroleum feedstock (FBR), catalytic cracking (MBR or FI BR), hydrodewaxing (FBR), steam reforming of methane or naphtha (FBR), water-gas shift (CO conversion) reaction (FBR-A), ammonia synthesis (FBR-A), methanol from synthesis gas (FBR), oxidation of sulfur dioxide (FBR-A), isomerization of xylenes (FBR-A), catalytic reforming of naphtha (FBR-A), reduction of nitrobenzene to aniline (FBR), butadiene from n-butanes (FBR-A), ethylbenzene by alkylation of benzene (FBR), dehydrogenation of ethylbenzene to styrene (FBR), methyl ethyl ketone from sec-butyl alcohol (by dehydrogenation) (FBR), formaldehyde from methanol (FBR), disproportionation of toluene (FBR-A), dehydration of ethanol (FBR-A), dimethylaniline from aniline and methanol (FBR), vinyl chloride from acetone (FBR), vinyl acetate from acetylene and acetic acid (FBR), phosgene from carbon monoxide (FBR), dichloroethane by oxichlorination of ethylene (FBR), oxidation of ethylene to ethylene oxide (FBR), oxidation of benzene to maleic anhydride (FBR), oxidation of toluene to benzaldehyde (FBR), phthalic anhydride from o-xylene (FBR), furane from butadiene (FBR), acrylonitrile by ammoxidation of propylene (FI BR)... 

Now, THF is produced by selective hydrogenation of maleic anhydride [6, 7] or by dehydration of 1,4 butanediol (resulting from acetylene and formaldehyde, followed by the hydrogenation of the resulting 2-butyne-l,4 diol [23]). The old technology based on furfurol may be reconsidered in the future, because it uses a renewable resource as its raw material. 

Dibromobutene diol is obtained by the addition of bromine to the triple bond of 2-butyne-1,4- diol (resulting from the addition of formaldehyde to acetylene), as shown in the reaction 18.4. 

Oxiranes are of considerable importance as intermediates for multistep stereospecific syntheses of complex target molecules, because closing and opening reactions of the oxirane ring often occur without side reactions. Moreover, they proceed stereospecifically. The first steps in the total syntheses of all 16 stereoisomeric hexoses may serve as an example. These syntheses start from ( )-but-2-ene-l,4-diol, 1, which is obtainable from acetylene and formaldehyde via butyne-l,4-diol [12]. 

The Reppe process is a method that was developed in the 1940s and typical manufacturers include BASF, Ashland, and Invista. Cu-Bi catalyst supported on silica is used to prepare the 1,4-butynediol by reacting formaldehyde and acetylene at 0.5 MPa and 90-110 C (Eq. (10.2)). The copper used in the reaction is converted to copper(I) acetylide, and the copper complex reacts with the additional acetylene to form the active catalyst. The role of bismuth is to inhibit the formation of water-soluble acetylene polymers (i.e., cuprenes) from the oligomeric acetylene complexes on the catalyst [5a]. The hydrogenation of 1,4-butynediol is accom-pUshed through the use of Raney Ni catalyst to produce 1,4-butanediol (Eq. (10.3)). The total yield of 1,4-butanediol production is 91% from acetylene [5b]. Since acetylene is a highly explosive compound, careful process control is necessary. 

Synthesis of butynediol from acetylene and formaldehyde reactor height 18 m, diameter 1.5 m, 100 °C, 3 bar, copper acetyhde catalyst, introduction of cold acetylene at various points in the reactor. 

Ca. 5% excess dry paraformaldehyde added in small portions with occasional cooling to gently refluxing ethereal p-tolyllithium prepared from p-iodotoluene and lithium, stirring continued 10-15 min. p-methylbenzyl alcohol. Y 95%. — It is not necessary to prepare monomeric formaldehyde from the paraformaldehyde. F. e., also C-hydroxymethylation of acetylene derivatives, s. A. Schaap, L. Brandsma, and J. F. Arens, R. 8A, 1200 (1965). 

LKl cfiemLCoC p oce ycng, syntheses of butynediol from aqueous formaldehyde and acetylene, selective hydrogenation of acetylene to remove it in the presence of butadiene in C4 hydrocarbon streams (31), and hydrogenation of glucose to sorbitol (6). 

Chromosorb 107 Porapak T Formaldehyde from water, acetylene from lower hydrocarbons Glycols and amines... 

The second largest volume polyester is polybutylene terephthalate, PBT, made from dimethyl terephthalate and 1,4-butanediol with a titanium alkox-ide catalyst. Butanediol can be prepared from acetylene and formaldehyde followed by reduction of the triple bond. 

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