Acetylenics ethylene

Energy source Process designation Feedstock Typical cracked gas concentrations, mol % Acetylene Ethylene ... 

Concentrations depend on severity of pyrolysis. At a high severity (- 2000° C) acetylene/ethylene ratio is 1, but at lower severity acetylene concentration is reduced and ethylene is increased. 

Hoechst WHP Process. The Hoechst WLP process uses an electric arc-heated hydrogen plasma at 3500—4000 K it was developed to industrial scale by Farbwerke Hoechst AG (8). Naphtha, or other Hquid hydrocarbon, is injected axially into the hot plasma and 60% of the feedstock is converted to acetylene, ethylene, hydrogen, soot, and other by-products in a residence time of 2—3 milliseconds Additional ethylene may be produced by a secondary injection of naphtha (Table 7, Case A), or by means of radial injection of the naphtha feed (Case B). The oil quenching also removes soot. 

H. Bockborn and co-workers, "Production of Acetylene ia Premixed Flames and of Acetylene—Ethylene Mixtures," Chem. Ing. Pechnol. 44(14), 869 (1972). "Thermal Decomposition of Ethane ia a Plasma Jet," Rogyo Kagaku Zasshil4(9), 83 (1971). 

Partial oxidation of natural gas or a fuel oil using oxygen may be used to form acetylene, ethylene (qv) and propylene (qv). The ethylene in turn may be partially oxidi2ed to form ethylene oxide (qv) via advantages (/) and (5). A few of the other chemicals produced using oxygen because of advantages (/) and (5) are vinyl acetate, vinyl chloride, perchloroethylene, acetaldehyde (qv), formaldehyde (qv), phthaHc anhydride, phenol (qv), alcohols, nitric acid (qv), and acryhc acid. 

A number of gases may decompose (self-react) and propagate flames in the absence of any oxidant provided that they are above minimum conditions of pressure, temperature, and pipe diameter. Common examples are acetylene, ethylene oxide, and ethylene. Some, like acetylene, can decompose in a detonative manner, while ethylene cannot detonate in the absence of an oxidant, whatever the run-up length (CCPS 1993). Thus, detonation arresters must be used for acetylene, but deflagration arresters may be used for ethylene, even for in-line applications. 

Decomposition Flames Flames that are produced hy exothermic decomposition of certain gases in the absence of any oxidant, provided that they are above minimum conditions of pressure, temperature, and pipe diameter. Common examples include acetylene, ethylene oxide, and ethylene. 

Butadiene CH2=CHCH= H2 Cu Acetylide, Vinyl Acetylene Ethylene Air (Peroxides) > 300 114 Inhibitor — t-Butyl Catechol — 115ppm Activation 12.0 429 Self-polymerization above RT or press... 

Nowadays silenes are well-known intermediates. A number of studies have been carried out to obtain more complex molecules having Si=C double bonds. Thus, an attempt has been made to generate and stabilize in a matrix 1,1-dimethyl-l-silabuta-l,3-diene [125], which can be formed as a primary product of pyrolysis of diallyldimethylsilane [126] (Korolev et al., 1985). However, when thermolysis was carried out at 750-800°C the absorptions of only two stable molecules, propene and 1,1-dimethylsilacyclobut-2-ene [127], were observed in the matrix IR spectra of the reaction products. At temperatures above 800°C both silane [126] and silacyclobutene [127] gave low-molecular hydrocarbons, methane, acetylene, ethylene and methylacetylene. A comparison of relative intensities of the IR... 

Grazing angle XAS techniques (XANES) can be applied to ultrathin film systems [316]. Selected NEX-AFS, XPS and FUR spectroscopy results were obtained for plasma-polymerised films with different monomers (styrene, acetylene, ethylene and butadiene) [317]. 

The first explicit information appeared in 1953 in two U.S. patents (9) which showed that platinum black as well as platinized asbestos or silica were effective for addition of trichlorosilane to olefins. Platinum on charcoal was unusually active with trichlorosilane and acetylene, ethylene, butadiene, vinyl chloride, or vinylidene fluoride. Temperatures as low as 130°C were sometimes employed. 

Operation at too high pressure (e.g., acetylene, ethylene, ethylene oxide)... 

Table 7.11 lists the predicted BDEs of TM compounds with 7r-donor ligands [4, 54, 55, 68-71], The complexes of W(CO)5 with acetylene, ethylene, and formaldehyde belong to the donor-acceptor class. The compounds of WC14 with the same ligands are metallacyclic molecules. 

Yamaki, D., Koch, H., Ten-no, S. Basis set limits of the second order Moller-Plesset correlation energies of water, methane, acetylene, ethylene, and benzene. J. Chem. Phys. 2007, 127, 144104. 

Acetic acid is one of the oldest known chemicals. Dilute acetic acid, vinegar, has been made by aerobic bacterial oxidation of ethanol. It has also been reclaimed by extraction or extractive distillation from pyroligneous acid, which was obtained from the extractive distillation of wood (J ). In the early nineteen hundreds, oxidation of acetaldehyde became the main source of acetic acid. The acetaldehyde has been obtained from acetylene ( ). ethylene (3) or ethanol as indicated below. 

Compounds which easily undergo exothermic decompn, such as hydrazine, acetylene, ethylene, etc... 

Acetylene is less stable thermodynamically relative to ethylene than ethylene is to ethane because AH for acetylene— ethylene is -177kJ/mol, while for ethylene— ethane it is -137kJ/mol. Therefore acetylene is more easily hydrogenated and the process can be stopped at the ethylene stage. In general, hydrogenation of alkynes can be stopped at the alkene stage. 

One of the characteristics of many catalytic hydrogenation reactions is the ability of the catalyst to promote the formation of more than one reaction product. Thus, for example, in the hydrogenation of acetylene, ethylene may be formed as an intermediate in the production of ethane and may be the major product in the initial stages of the reaction... 

The reported rate equations for the hydrohalogenation of acetylene, ethylene, propene and vinyl chloride are summarised in Table 15. Of special interest is the last entry it is based on a model which assumes two types of active centres, the first one for the adsorption of acetylene, the second for the adsorption of hydrogen chloride and vinyl chloride. 

In the absence of oxygen, about 82 peaks of hydrocarbon products were observed in the gas chromatogram, which showed that the main products consisted of C6 hydrocarbons (Table IV), hydrogen, methane, acetylene, ethylene, ethane, methylacetylene, allene, propane, 1-butene, and butadiene. 

---