Acetylene industrial source

Acetylene is a tricky chemical feedstock. It is extremely reactive (and explosive) and impractical to transport. Generally, the industrial processes that use acetylene are close to the acetylene-generating source. Despite all the drawbacks, the Reppe process was for a half century the preferred process for EDO, but now the growth in EDO is being taken by the propylene oxide (PO) and butane feedstock routes. 

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. 

With each succeeding year in the 1950s and 1960s there was a swing away from coal and vegetable sources of raw materials towards petroleum. Today such products as terephthalic acid, styrene, benzene, formaldehyde, vinyl acetate and acrylonitrile are produced from petroleum sources. Large industrial concerns that had been built on acetylene chemistry became based on petrochemicals whilst coal tar is no longer an indispensable source of aromatics. 

Although the current source of acetylene is petroleum, it can be manufactured from calcium carbide, a product of the reachon of limestone and coke (carbon). During World War II, Germany, having a shortage of petroleum, used the latter technology to develop a chemical industry based on acetylene. 

Acrylic Acid and Acrylates. Acrylic acid and acrylates may be produced commercially by the Reppe reaction of acetylene.76,184-187 However, the industrial significance of these processes has diminished since acetylene is no longer a viable source and was replaced by ethylene. Acrylic acid and acrylates are now produced by propylene oxidation (see Section 9.5.2). 

Laboratory and industrial-scale processes show that acetylene is one intermediate in carbon formation in the combustion of petroleum hydrocarbons. This is not only a result of thermal decomposition but a part of the complex of reactions occurring in the oxidation system. Steps resulting in the immediate production of acetylene seem to be molecular decomposition of molecules, or free radicals, or dehydrogenation, followed by combination or addition of oxygen. Peroxide formation may occur also. These reactions may be a general source of the hydrocarbon flame bands. 

Abstract. Nanocarbon materials and method of their production, developed by TMSpetsmash Ltd. (Kyiv, Ukraine), are reviewed. Multiwall carbon nanotubes with surface area 200-500 m2/g are produced in industrial scale with use of CVD method. Ethylene is used as a source of carbon and Fe-Mo-Al- mixed oxides as catalysts. Fumed silica is used as a pseudo-liquid diluent in order to decrease aggregation of nanotubes and bulk density of the products. Porous carbon nanofibers with surface area near 300-500 m2/g are produced from acetylene with use of (Fe, Co, Sn)/C/Al203-Si02 catalysts prepared mechanochemically. High surface area microporous nanocarbon materials were prepared by activation of carbon nanofibers. Effective surface area of these nanomaterials reaches 4000-6000 m2/g (by argon desorption method). Such materials are prospective for electrochemical applications. Methods of catalysts synthesis for CVD of nanocarbon materials and mechanisms of catalytic CVD are discussed. 

All industrial vitamin A syntheses use p-ionone as the starting compound (36, see page 14) 3S). This monocyclic C13 ketone can be obtained either completely synthetically from acetone and acetylene by consequent use of the C2 and C3 addition reaction, or via citral (59, see page 14) obtainable from natural sources (lemongrass oil). 

Flame methods are the conventional atomization sources used in MS for industrial hygiene (Table I). Air/acetylene at 2150-2400°C is used for the easily atomized elements like lead, cadmium, and zinc. Refractory metals such as tungsten or vanadium require hotter nitrous oxide/acetylene atomization at 2600-2800 C. The need for greater sensitivity and multielement analysis from a single filter has increased the use of electrothermal atomization for tin, vanadium, nickel, and other difficult elements. Formation of hydrides combined with flame atomization has been used in some cases to increase sensitivity. 

The flame is still by far the most popular and convenient atomisation source employed in AAS. It provides sufficient sensitivity for most trace metal analysis requirements met in the petroleum industry. Methods are described for use with both aur-acetylene and nitrous oxide—acetylene flames. The properties of these flames are described in Chapter 2. 

New sources of raw materials for explosive manufacture have been made available from acetylene and from natural gas and petroleum products. In TNT manufacture, for instance, we no longer depend solely on toluene from coking operations. Even greater quantities are being provided by the petroleum industry. 

In the early part of this century, coal and coal tar products were the main source of bulk chemicals. Acetylene was the major feedstock, obtained by converting coal to calcium carbide followed by hydrolysis. As the petroleum and natural gas industries developed, ethylene and other products obtained by cracking hydrocar-... 

Chrysene occurs as a product of combustion of fossil fuels and has been detected in automobile exhaust. Chrysene has also been detected in air samples collected from a variety of regions nationally and internationally. The concentrations were dependent on proximity to nearby sources of pollution such as traffic highways and industries, and was also dependent on seasons (generally higher concentrations were noted in winter months). Chrysene has also been detected in cigarette smoke and in other kinds of soot and smoke samples (carbon black soot, wood smoke, and soot from premixed acetylene oxygen flames). It has been detected as a component in petroleum products including clarified oil, solvents, waxes, tar oil, petrolatum, creosote, coal tar, cracked petroleum residue, extracts of bituminous coal, extracts from shale, petroleum asphalts, and coal tar pitch. 

In industry, methane is used to make methanol, halogenated methanes, ethylene, carbon tetrachloride, chloroform, acetylene, hydrogen cyanide, and methyl chloride. In the form of natural gas, methane is used as a fuel, as a source of carbon black, and as a starting material for the manufacture of synthetic proteins. It is also used in gas-fired utilities and in the home (home heating, gas dryers, and gas cooking). 

Coal tar dyes mark the beginning of the chemical industry in the UK, in France and in the Rhine Valley with chemists like August Wilhelm Hofmann and William Henry Perkin and company names like Ciba, BASF, Hoechst and Bayer. Since the last century crude oil and natural gas have become the key raw material sources for the modern chemical industry yielding all base chemicals like olefins, acetylene and more particularly aromatics. In the future, as in the past, a reliable and economically reasonable supply of carbon and hydrogen as raw material source for basic chemicals and their derivatives will be the basic requirement for the chemical industry. ... 

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