Reference product: ethanol, without water, in 99.7% solution state, from ethylene [kg]
Location: RER - Europe
This dataset represents the hydration of 1 kg of ethylene, which is a multi-output process which delivers the co-products ethanol 99.7% in H2O and diethyl ether 99.95% in H2O.
Depending on its water content, preparation, and final use, several ethanol products exist on the market. The 99.7% alcohol (often referred to as absolute alcohol) is used extensively for tinctures and pharmaceutical preparations, as a solvent and preservative, as an antiseptic, and in perfume. Ethanol is an important functional component of alcoholic beverages, which are produced by fermentation of fermentable carbohydrates. The fermentation broth itself may constitute (after processing and aging) a beverage, e.g., in the case of beer or wine, or the alcohol can be concentrated from the broth to produce high-alcohol-containing spirits. If the alcohol is used for purposes other than as a beverage, it is denatured by the addition of substances such as methanol, pyridine, formaldehyde, or sublimate. The denatured alcohol is then used by industry and commerce, principally as a solvent, as a raw material for manufacturing chemicals, or as a fuel.
Diethyl ether (CH3CH2–O–CH2CH3) is one of the most important ethers. It is a clear, mobile liquid with a sweetish, slightly pungent, characteristic odor. It is completeley miscible with common organic solvents, but only partially miscible with water. Two grades of diethyl ether are commercially available: technical-grade ether and anesthetic ether. There are no universally accepted specifications for technical-grade ether, but it is conventionally free of peroxides. Anhydrous technical-grade ether has a maximum water content of 500 mg/kg. Anesthetic ether has a neutral reaction, is free from foreign odors, passes the tests for peroxides and aldehydes, and has a maximum water content of 0.2 %. Diethyl ether is a good solvent for many oils, fats, resins, alkaloids, odorants, and dyes and, therefore, is widely used as a solvent and as an extractant. When mixed with ethanol, diethyl ether is used to gel nitrocellulose and to dissolve collodion wool. Ether is used as a reaction medium in the laboratory and in industry due to its chemical stability, low boiling point, and solvent properties for organometallic compounds (Grignard reagents).
Ethylene can be hydrated in two ways: by indirect hydration or by direct hydration. This dataset represents the direct hydration process. The data for raw materials, energy consumption and emissions are based on literature data. The infrastructure is included with a default value.
Sutter, J. (2007) Life Cycle Inventories of Petrochemical Solvents. ecoinvent report No. 22. Swiss Centre for Life Cycle Inventories, Dübendorf, 2007.
[This dataset has been generated using the system model "Allocation, cut-off by classification". A system model describes how activity datasets are linked to form product systems. The allocation cut-off system model subdivides multi-product activities by allocation, based on a physical properties, economic, mass or other properties. By-products of waste treatment processes are cut-off, as are all by-products classified as recyclable. Markets in this model include all activities in proportion to their current production volume.
Version 3 of the ecoinvent database offers three system models to choose from. For more information, please visit: https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html)]
The catalytic hydration of ethylene is a heterogeneous process in gaseous phase on acid catalyst, where the catalyst is H3PO4, and takes place at a temperature of 300°C and pressure of 70 bars. The ethylene conversion is only of 4% per passage. The reaction gas is recycled many times to increase total efficiency. The ethylene has to be of high purity to avoid inert gases concentration. The reaction gas is cooled to condense the liquid products and separate it from the ethylene to be recycled. Ethanol solution is concentrated and purified by extractive distillation. The ethanol selectivity is about 98%. Co-products of the direct hydration are diethyl ether (1 %), butene (0.6 %), and acetaldehyde (0.2 %). The diethyl ether is purificated in the ether distillation column. The other organic byproducts are recovered and fed into the steam generator.
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The figure below represents the production of ethanol by means of the direct hydration of ethanol.
[To see the image, please follow the link https://db3.ecoinvent.org/images/17074383-522e-48a7-9423-ac17d99cbff4]
a) Circulation compressor; b) Heat exchanger; c) Superheater; d) Reactor; e) Washer; f) Crude ethanol tank; g) Extractive distillation column; h) Concentration column; i) Dehydration; j) Concentration column
Heitmann, W., Strehlke, G., Mayer, D.: Ethers, aliphatic, Chapter 2,4. In: Ullmann's Encyclopedia of Industrial Chemistry, Seventh Edition, 2004 Elec-tronic Release (ed. Fiedler E., Grossmann G., Kersebohm D., Weiss G. and Witte C.). 7 th Electronic Release Edition. Wiley InterScience, New York, Online-Version under: http://www.mrw.interscience.wiley.com/ueic/articles/ arti-cles/a10_023/