glyoxal production, UPR, ecoinvent 3.6, Allocation, cut-off
Reference product: glyoxal [kg]
Location: RoW - Rest-of-World
The process “glyoxal, at plant, GLO" is modelled for the production of glyoxal from ethylene oxide. Raw materials are modelled with a stoechiometric calculation. Emissions are estimated. Energy consumptions, infrastructure and transports are calculated with standard values.
Glyoxal (C2H2O2; CAS 107-22-2, ethanedial, diformyl) is a liquid at ambient temperature; it crystallizes at 15 °C in the form of yellow prismatic crystals and boils at 50.4 °C (101.3 kPa), giving off green vapors with a pungent odour. Glyoxal can be produced by oxidation of ethylene oxide.
C2H4O + O2 → C2H2O + H2O
Other routes are:
Oxidation with nitric acid was examined by Ljubowin as early as 1875 and patented in 1942. Reaction takes place at ca. 40 °C and is carried out industrially as a continuous process. Maximum yield is ca. 70 %; selectivity is a function of the relative concentrations of reagents. After the removal of excess acetaldehyde, the glyoxal formed, which is contaminated with acetic, formic, and glyoxylic acids, is purified by passage of the aqueous solution through an ion-exchange resin. The solution is then concentrated to a glyoxal content of about 40 %.
Selenium oxide is more selective than nitric acid, and the yield is ca. 84 %; the selenium can be recycled by oxidation with hydrogen peroxide. This process has not been carried out on an industrial scale.
From Ethylene Glycol
The gas-phase oxidation of ethylene glycol by atmospheric oxygen in the presence of dehydrogenation catalysts (metallic copper or silver) represents the basis of the Laporte process and has been used in several industrial production processes. Reaction occurs between 400 and 600 °C; the yield is 70 – 80 %. The main impurity is formaldehyde, whose subsequent separation is difficult. This reaction has also been carried out in the liquid phase and under irradiation.
Ethylene can be oxidized by aqueous nitric acid in the presence of palladium, by atmospheric oxygen, or by selenium oxide deposited on silica. Glyoxal may also be formed by oxidation of acetylene or benzene with ozone. impurity is formaldehyde, whose subsequent separation is difficult. This reaction has also been carried out in the liquid phase and under irradiation.
Ethylene can be oxidized by aqueous nitric acid in the presence of palladium, by atmospheric oxygen, or by selenium oxide deposited on silica. Glyoxal may also be formed by oxidation of acetylene or benzene with ozone.
Glyoxal is supplied mainly as a 40 % aqueous solution. Various polyhydroxy polymers (e.g., starch or poly(vinyl alcohol)) can be used to stabilize glyoxal.
The bifunctionality of glyoxal has been used to cross-link functionalized macromolecules such as cellulose, polyacrylamides, poly(vinyl alcohol), keratin, and other polycondensates. For example, glyoxal is used as a cross-linking agent for imparting wet strength to coated paper. With cellulose, unstable hemiacetals are obtained in the cold, which irreversibly form acetals when heated in the presence of acid catalysts .
The reducing properties of glyoxal are used in the photographic industry and in glassmaking for the production of silvered glass mirrors.
Glyoxal bisulfite (available as the monohydrate) is used as a resist agent in printing with reactive dyes and as a leveling agent in dyeing polyamide with acid dyes.
An important class of molecules used as cross-linking agents is obtained by nucleophilic substitution of glyoxal. Examples include the bisacrylamide and the tetraallylacetal.
Glyoxalbisacrylamide is used for the functionalization of ion-exchange resins and in latices for treating textiles. Tetraallyloxyethane is used as a cross-linking agent for polyacrylates and for pressure-sensitive adhesives.
Glyoxal is used in the fine chemicals industry for the production of various heterocyclic compounds including tetraacetylglycoluril, imidazoles such as metronidazole that are effective against anaerobic bacteria, and the pyrazine derivatives sulfapyrazine, thionazine, and pyrazinamide.
Glyoxal has bactericidal properties comparable with those of glutaraldehyde and is used as a disinfectant.
Frischknecht R., Jungbluth N., Althaus H.-J., Doka G., Dones R., Heck T., Hellweg S., Hischier R., Nemecek T., Rebitzer G. and Spielmann M. (2007) Overview and Methodology. Final report ecoinvent v2.0 No. 1. Swiss Centre for Life Cycle Inventories, Dübendorf, CH, retrieved from: www.ecoinvent.org.
Gendorf (2000) Umwelterklärung 2000, Werk Gendorf. Werk Gendorf, Burgkirchen as pdf-File under: http://www.gendorf.de/pdf/umwelterklaerung2000.pdf
Georges Mattioda/Alain Blanc: Glyoxal. Published online: 2000. In: Ullmann's Encyclopedia of Industrial Che-mistry, Seventh Edition, 2004 Electronic 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: DOI: 10.1002/14356007.a12_491
[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)]
oxidation of ethylene oxide