Ethanol from acetylene

Which of the following conditions would you use if you needed to develop an industrial process to produce ethanol from acetylene Explain. 

Consider the production of ethanol from acetylene and water at 355 K and 1 bar by the following reaction ... 

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 — ... 

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. 

Hydrogenation of Acetaldehyde. Acetaldehyde made from acetylene can be hydrogenated to ethanol with the aid of a supported nickel catalyst at 150°C (156). A large excess of hydrogen containing 0.3% of oxygen is recommended to reduce the formation of ethyl ether. Anhydrous ethanol has also been made by hydrogenating acetaldehyde over a copper-on-pumice catalyst (157). 

Source Manufactured by oxidizing ethanol with sodium dichromate and sulfuric acid or from acetylene, dilute sulfuric acid, and mercuric oxide catalyst. 

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. 

Type 4A sieves. The pore size is about 4 Angstroms, so that, besides water, the ethane molecules (but not butane) can be adsorbed. Other molecules removed from mixtures include carbon dioxide, hydrogen sulphide, sulphur dioxide, ammonia, methanol, ethanol, ethylene, acetylene, propylene, n-propyl alcohol, ethylene oxide and (below -30°) nitrogen, oxygen and methane. The material is supplied as beads, pellets or powder. 

Acetaldehyde is a useful huilding block for acetic aod, acetic anhydride. and chloral Ills currently produced from ethylene, ethanol, propane, and butane Production from acetylene appear to be outdated... 

Because water is a product and the recycle ethanol will be wet, the ethanol feedstock need not be the highest grade, but instead the easier to produce hydrous ethanol (95% ethanol). If the reaction temperature is low, there should be no contamination from acetylene, which is a problem with higher temperature routes. 

Acetaldehyde decomposes at a measurable rate in the temperature range 450-600 °C. At the pressures generally employed (30-300 torr), the main products are CO and CH4, which are formed in nearly equimolar amounts. Ethane, ethylene, hydrogen and propionaldehyde have also been detected. Under certain conditions small amounts of ethanol and acetylene were observed. At very low pressures the reaction products and the kinetics of the reaction seem to differ completely from normal ... 

After its discovery this process attracted the highest industrial interest and many plants have been erected in industrial countries all over the world. It replaced processes starting from acetylene or ethanol almost completely. The process is operated in two versions, both in a homogeneous phase [47]. 

The first mesoporous carbon examples are CMK-1[32] with symmetry /4i32 from sucrose, and CMK-4 from acetylene with symmetry laid, by using MCM-48 as template. For the synthesis of CMK-1, MCM-48 was impregnated with sucrose and sulfuric acid, both as an aqueous solution. The impregnated MCM-48 was heated to a desired temperature, in the range of 1073-1373 K (800-1100 °C), under vacuum or in an inert atmosphere. The sucrose was converted into carbon by such a process using sulfuric acid as the catalyst. Finally, the silica framework was removed by dissolution in aqueous solution containing NaOH and ethanol. 

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)... 

Although acetaldehyde may generally be more economically produced from acetylene by hydration, the high yields that may be obtained by the dehydrogenation of ethanol show the excellent directive powers of the copper catalysts for this reaction. By operating at temperatures below... 

Although alcohol has been produced by the hydrogenation of acetaldehyde obtained from the hydration of acetylene, this source is relatively unimportant ordinarily. It does, however, furnish a means for the synthesis of ethanol from such sources of carbon as calcium carbide, methane, the carbon arc, etc., which might become of importaice during periods of war, or in locations where very cheap electric power is available. Experiments on a technical scale78 in Switzerland have shown the process to be successful but at a cost too high to make the process competitive. 

Ethyl Acrylate. 2-Propenoic acid ethyl ester acryl -ic acid ethyl ester, CsH(02 mol wt 100.11. C 59.98%, H 8.05%, O 31.96%. CH.=CHCOOCH2CH,. Prepd from ethylene chlorohydrin or acrylonitrile, ethanol, and sulfuric acid also by an oxo reaction from acetylene, carbon monoxide, and ethanol in the presence of suitable catalysts. See the refs under Methyl Acrylate,... 

Acetaldehyde can be produced by the partial oxidation of ethanol and the direct oxidation of ethylene. The predominant commercial process, however, is the direct liquid phase oxidation of ethylene. As with many other ethylene-based petrochemicals, acetaldehyde was first produced commercially from acetylene. The acetylene process was developed in Germany more than 70 years ago and was still practiced until the mid-1970s when the high cost and scarcity of acetylene forced it into obsolescence. Another early route to acetaldehyde was based on ethanol. Ethyl alcohol can be either oxidized or alternatively dehydrogenated to acetaldehyde. Site-... 

Butadiene is obtained commercially by dehydrogenation of butane or butene or from the cracked naphtha C4 fraction. Older processes using ethanol or acetylene are no longer economic. 

Hydrostannation. Enestannanes from acetylene derivs. An equimolar amount of NaBH4 in ethanol added dropwise to tri-n-butyl-tin chloride in abs. ethanol, stirred 10 min. at 25°, propargyl 2-tetrahydropyranyl ether added, and refluxed 3.5 hrs. -> trans-3-tri-rt-butylstannyl-2 -propenyl 2-tetrahydropyranyl ether. 

Also, ethyl acrylate may be prepared in one step from acetylene, carbon monoxide and ethanol. The solution technique described in Section 6.2.1 does not appear to be used in this way but a process involving nickel carbonyl and hydrochloric acid is operated commercially. The stoichiometric equation for the reaction is ... 

To a suspension of a tinc-copper couple in 150 ml of 100 ethanol, prepared from 80 g of zinc powder (see Chapter II, Exp. 18), was added at room temperature 0.10 mol of the acetylenic chloride (see Chapter VIII-2, Exp. 7). After a few minutes an exothermic reaction started and the temperature rose to 45-50°C (note 1). When this reaction had subsided, the mixture was cooled to 35-40°C and 0,40 mol of the chloride was added over a period of 15 min, while maintaining the temperature around 40°C (occasional cooling). After the addition stirring was continued for 30 min at 55°C, then the mixture was cooled to room temperature and the upper layer was decanted off. The black slurry of zinc was rinsed five times with 50-ml portions of diethyl ether. The alcoholic solution and the extracts were combined and washed three times with 100-ml portions of 2 N HCl, saturated with ammonium chloride. 

Acetaldehyde [75-07-0] (ethanal), CH CHO, was first prepared by Scheele ia 1774, by the action of manganese dioxide [1313-13-9] and sulfuric acid [7664-93-9] on ethanol [64-17-5]. The stmcture of acetaldehyde was estabhshed in 1835 by Liebig from a pure sample prepared by oxidising ethyl alcohol with chromic acid. Liebig named the compound "aldehyde" from the Latin words translated as al(cohol) dehyd(rogenated). The formation of acetaldehyde by the addition of water [7732-18-5] to acetylene [74-86-2] was observed by Kutscherow] in 1881. 

Acetaldehyde, first used extensively during World War I as a starting material for making acetone [67-64-1] from acetic acid [64-19-7] is currendy an important intermediate in the production of acetic acid, acetic anhydride [108-24-7] ethyl acetate [141-78-6] peracetic acid [79-21 -0] pentaerythritol [115-77-5] chloral [302-17-0], glyoxal [107-22-2], aLkylamines, and pyridines. Commercial processes for acetaldehyde production include the oxidation or dehydrogenation of ethanol, the addition of water to acetylene, the partial oxidation of hydrocarbons, and the direct oxidation of ethylene [74-85-1]. In 1989, it was estimated that 28 companies having more than 98% of the wodd s 2.5 megaton per year plant capacity used the Wacker-Hoechst processes for the direct oxidation of ethylene. 

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