Acetylene butadiene from

The pattern of commercial production of 1,3-butadiene parallels the overall development of the petrochemical industry. Since its discovery via pyrolysis of various organic materials, butadiene has been manufactured from acetylene as weU as ethanol, both via butanediols (1,3- and 1,4-) as intermediates (see Acetylene-DERIVED chemicals). On a global basis, the importance of these processes has decreased substantially because of the increasing production of butadiene from petroleum sources. China and India stiU convert ethanol to butadiene using the two-step process while Poland and the former USSR use a one-step process (229,230). In the past butadiene also was produced by the dehydrogenation of / -butane and oxydehydrogenation of / -butenes. However, butadiene is now primarily produced as a by-product in the steam cracking of hydrocarbon streams to produce ethylene. Except under market dislocation situations, butadiene is almost exclusively manufactured by this process in the United States, Western Europe, and Japan. 

Acetonitrile serves to greatly enlarge the spread of relative volatilities so that reasonably sized distillation equipment can be used to separate butadiene from the other components in the C4 fraction. The polar ACN acts as a very heavy component and is separated from the product without much difficulty.The feed stream is carefully hydrogenated to reduce the acetylene level rerun, and then fed to the single stage extractive distillation unit. Feed enters near the middle of the extractive distillation tower, while (lean) aqueous ACN is added near but not at the top. Butenes and butanes go overhead as distillate, with some being refluxed to the tower and the rest water washed for removal of entrained ACN. 

Nickel cyanide is used for nickel plating. It also is used to synthesize butadiene from acetylene. 

The computed transition state of the [4+2]-cycloaddition between ethene and butadiene is shown in Figure 15.2 (top), along with the computed transition state of the [4+2]-cycloaddi-tion between acetylene and butadiene. It is characteristic of the stereochemistry of these transition states that ethene or acetylene, respectively, approaches the cw-conformer of butadiene from a face (and not in-plane). Figure 15.2 also shows that the respective cycloadducts— cyclohexene or 1,4-cyclohexadiene—initially result in the twist-boat conformation. 

The primary source of isoprene today is as a by-product in the production of ethylene via naphtha cracking. A solvent extraction process is employed. Much less isoprene is produced in the crackers than butadiene, so the availability of isoprene is much more limited. Isoprene also may be produced by the catalytic dehydrogenation of amylenes, which are available in C-5 refinery streams. It also can be produced from propylene by a dimerization process, followed by isomerization and steam cracking. A third route involves the use of acetone and acetylene, produced from coal via calcium carbide. The resulting 3-methyl-butyne-3-ol is hydrogenated to methyl butanol and subsequently dehydrogenated to give isoprene. The plants that were built on these last two processes have been shut down, evidently because of the relatively low cost of the extraction route. 

This method provides a simple one-step synthesis of 2,3-diphenyl-1,3-butadiene from the readily available diphenyl-acetylene. It illustrates an unusual reaction that has been relatively uninvestigated. The scope of the reaction is unknown, but it would appear that the procedure could be applied to disubstituted acetylenes having aryl substituents that contain functionality that is unaffected by the strong basic conditions of the reaction. 

The extraction of butadiene involves solvent extraction and distillation. In the process shown in Figure 5.2 , a mixed C4 steam enters a solvent stripping column (1) which strips the butadiene and acetylene compounds from the stream. A typical solvent is N-methylpyrolidone (NMP). 

Ammonia, acetylene, butadiene, butane, other petrolerrm gases, hydrogen, sodium carbide, turpentine, benzene, and finely divided metals Ammonia, methane, phosphine, and hydrogen sulfide Acetylene, hydrogen peroxide Isolate from everything... 

Production of Coke and Other Pyrolysis Products From Acetylene, Butadiene, and Benzene in Various Tubular Reactors... 

Thermal reactions of acetylene, butadiene, and benzene result in the production of coke, liquid products, and various gaseous products at temperatures varying from 4500 to 800°C. The relative ratios of these products and the conversions of the feed hydrocarbon were significantly affected in many cases by the materials of construction and by the past history of the tubular reactor used. Higher conversions of acetylene and benzene occurred in the Incoloy 800 reactor than in either the aluminized Incoloy 800 or the Vycor glass reactor. Butadiene conversions were similar in all reactors. The coke that formed on Incoloy 800 from acetylene catalyzed additional coke formation. Methods are suggested for decreasing the rates of coke production in commercial pyrolysis furnaces. 

Diene Cyclization. In 1952 Reed (157) discovered the catalytic dimerization of butadiene with Reppe catalyst in the presence of acetylene. Important results were obtained by Wilke (200) in the cyclization of butadiene with a nickel(0) catalyst. With bis-7r-allylnickel, biscyclo-i,5-octadienenickel, or cyclododecatrienenickel, he obtained the trimerization of butadiene to cyclododecatetraene while, with a catalyst of the type Ni(PR3)4, in which perhaps one coordination site cannot be replaced, he obtained the dimerization to cycloocta-l,5-diene. The mechanism of these reactions, in which 7r-allyl systems can be in equilibrium with o--7r-allyl systems (Figure 7), have been proved by Wilke and co-workers who isolated the intermediate compounds. It is worth noting that all these catalysts have ligands of weak -acceptor character which are labile and do not prevent butadiene from coordinating. The presence of weak t acceptors on the nickel tends to favor the structure of the diene, as was emphasized by Mason (112). 

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)... 

First there was the chemistry of olefins which owing to Germany s oil deficiency could not be obtained by cracking, but had to be produced by hydrogenation of acetylene originating from coal via calcium carbide. At the beginning of the 1920 s, acetylene was used first for addition reactions at normal pressure the most important product was acetaldehyde which via aldol, 1,3-butanediol, and butadiene led to synthetic rubber. Other important products were ethylene oxide, acrylic esters, styrene, etc. 

Thermoplastic polymers were also earlier reported to have been prepared by heating tricyclodecane dithiol with terephthaloyl chloride in a chlorinated solvent [16b]. Additional examples are cited for polythioesters based on bis-phenol A and random other polythioesters derived from bicyclic thiols. The starting diolefins for the dithols are prepared by the Diels-Alder synthesis using cyclopentadiene, acetylene, butadiene, etc. 

In 1953, Karl Ziegler had discovered the polymerisation of ethylene at normal pressure he succeeded in polymerising ethylene to polyethylene in a 5-litre preserving jar with a mixture of titanium tetrachloride and diethyl-aluminium chloride (Fig. 3.43). At the end of the 1950s, Gunther WHke intended to prepare butadiene from acetylene and ethylene with Ziegler catalysts, but preliminary experiments showed that the selected catalysts reacted violently with butadiene, and that the product was not a polymer but cyclododecatriene. Wilke later foimd, by using Ni(0)-com-plexes (which he called naked nickel ), that the isomer ratio was clearly in favour of the zH-trans isomer. 

Several processes starting from acetylene, butadiene, maleic anhydride or propylene have been recently developped for the production of butanediol. Various possibilities are shown on Figure... 

As illustrated in the early achievements from Reppe on the cyclotetramerization of acetylene and from Wilke on the cyclodimerization and cyclotrimerization of butadienes, nickel-catalyzed cycloadditions possess considerable potential in the construction of medium ring systems. Pioneering studies by Wender have demonstrated many practical implications that have advanced the... 

A mixture of 3,6-diphenyl-si/m-tetrazine, diphenylacetylene, and toluene refluxed 3 days 3,4,5,6-tetraphenylpyridazine. Y 86%.—A variety of unsatd. compounds, inch aliphatic and alicyclic olefins, styrenes, acetylenes, butadienes, and allene give the above reaction. 3,6-Bis(polyfluoroalkyl)-sym-tetrazines react with particular ease. F. e., also from ethylene derivatives via 1,4-dihydropyridazines, s. R. A. Garboni and R. V. Lindsey, Jr., Am. Soc. 81, 4342 (1959). 

From the very beginning up to the 1960s, chloroprene was produced by the older energy-intensive acetylene process using acetylene, derived from calcium carbide [3]. The acetylene process had the additional disadvantage of high investment costs because of the difficulty of controlling the conversion of acetylene into chloroprene. The modern butadiene process, which is now used by nearly all chloroprene producers, is based on the readily available butadiene [3]. 

Nowadays, both monomers are made from petroleum. However, it is interesting to note that during the Second World War, both Russia and the United States produced butadiene from grain alcohol. At about the same time, German chemists developed a number of synthetic routes from coal via acetylene. Yet another route to butadiene started with oat husks, from which were obtained pentosans and in turn, furfuraldehyde, tetrahydro-furan and butadiene. Styrene may also be produced from a number of materials, particularly from coal. 

In the United States butadiene was prepared initially from ethanol and later by cracking four-carbon hydrocarbon streams (see Butadiene). In Germany butadiene was prepared from acetylene via the following steps acetylene — acetaldehyde — 3-hydroxybutyraldehyde — 1,3-butanediol — ... 

Another use is in various extraction and absorption processes for the purification of acetylene or butadiene and for separation of aHphatic hydrocarbons, which have limited solubiHty in DMF, from aromatic hydrocarbons. DMF has also been used to recover CO2 from flue gases. Because of the high solubiHty of SO2 iu DMF, this method can even be used for exhaust streams from processes using high sulfur fuels. The CO2 is not contaminated with sulfur-containing impurities, which are recovered from the DMF in a separate step (29). 

Aliphatic Chemicals. The primary aliphatic hydrocarbons used in chemical manufacture are ethylene (qv), propjiene (qv), butadiene (qv), acetylene, and / -paraffins (see Hydrocarbons, acetylene). In order to be useflil as an intermediate, a hydrocarbon must have some reactivity. In practice, this means that those paraffins lighter than hexane have Httle use as intermediates. Table 5 gives 1991 production and sales from petroleum and natural gas. Information on uses of the C —C saturated hydrocarbons are available in the Hterature (see Hydrocarbons, C —C ). 

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