Location: RER - Europe
The process “sodium nitrite, at plant, RER” is modelled for the production of sodium nitrite from nitrous dioxide in Europe. Raw materials are modelled with a stoechiometric calculation. Emissions are estimated. Energy consumptions, infrastructure and transports are calculated with standard values.
Sodium nitrite (NaNO2; CAS 7632-00-0) forms colourless crystals. It is hygroscopic. The anhydrous salt has an enthalpy of solution of ΔH298 = +13.9 kJ/mol at infinite dilution. The hydrate NaNO2 • 0.5H2O exists below –5 °C. Sodium nitrite is soluble in liquid ammonia; 2NaNO2 • NH3 forms below –64 °C. The solubility of sodium nitrite in 95% ethanol at 25 °C is ca. 1.4%.

Until the beginning of the 20th century, sodium nitrite was produced by the reduction of sodium nitrate with lead, iron, zinc, manganese dioxide, coke, sulfur dioxide, and calcium carbide. Of these processes, the only one of industrial significance was the reduction of molten sodium nitrate with lead at ca. 400 °C.
Large-scale production of sodium nitrite is now based on the reaction of nitrogen oxides with sodium carbonate or sodium hydroxide solution.

Large amounts of sodium nitrite are consumed in the chemical and pharmaceutical industries for the production of nitroso and isonitroso compounds, diazotization reactions, and the synthesis of pharmaceuticals and agricultural pesticides.
Other applications of sodium nitrite are in metallurgy and corrosion prevention. It is used as an accelerator in phosphating, added to alkaline pickling solutions for aluminum, applied to steel as a descaling agent, added to drilling oils and abrasives, used for passivating metal surfaces and for creating protective coatings on carbon steels, and added as a corrosion inhibitor to lubricating oils and greases as well as to cooling water loops. Sodium nitrite serves as an oxidizing agent in the alkaline detinning of tinplate scrap and a corrosion inhibitor in heat-transfer baths.
Sodium nitrite is used in lubricants for glass-forming equipment. Like sodium nitrate and potassium nitrate, it is used as a heat-transfer medium.
Sodium nitrite is recommended as an additive in concrete and gypsum to improve strength and combat the corrosion of iron reinforcement.
In curing salts used in the food industry, sodium nitrite is still the most reliable agent for protecting against botulism, a dangerous bacterial contaminant of meats. High nitrite concentrations can, however, lead to the formation of carcinogenic nitrosamines; legislative restrictions have, therefore, been imposed on the use of nitrite. Methods have been developed for achieving a satisfactory effect with minimal quantities. The simultaneous addition of other substances (e.g., ascorbic acid) is reported to prevent the formation of nitrosamines.

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
Kim 2003 Kim S., Overcash M.: Energy in chemical manufacturing processes: gate-to-gate information for life cycle assessment. In: Journal of Chemical Technology & Biotechnology vol. 78, no. 9: 995-1005(11). 2003

Wolfgang Laue, Michael Thiemann, Erich Scheibler, Karl Wilhelm Wiegand: Nitrates and Nitrites. Published online: 2002. In: Ullmann's Encyclopedia of Industrial Chemistry, 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.a17_265

Undefined unit processes (UPRs) are the unlinked, multi-product activity datasets that form the basis for all of the system models available in the ecoinvent database. This is the way the datasets are obtained and entered into the database by the data providers. These activity datasets are useful for investigating the environmental impacts of a specific activity (gate-to-gate), without regard to its upstream or downstream impacts.