Location: RER - Europe
The process “chlorosulfonic acid, at plant, RER” is modelled for the production of chlorosulfonic acid from sulfur trioxide in Europe. Raw materials are modelled with a stoechiometric calculation. Emissions are estimated. Energy consumptions, infrastructure and transports are calculated with standard values.
Chlorosulfuric acid (HSO3Cl; CAS 7790-94-5, chlorosulfonic acid, sulfuryl hydroxychloride, sulfuric chlorohydrin, sulfonic acid monochloride, chlorohydrated sulfuric acid) is a colourless, mobile, extremely reactive liquid. Chlorosulfuric acid is a strong acid, stable under normal conditions. It is highly corrosive and hygroscopic. All the industrial routes to chlorosulfuric acid are based on the reaction of hydrogen chloride with sulfur trioxid.
Earlier processes made use of contact process gas which contains 6 – 7 % SO3, but today it is more usual to use pure sulfur trioxide. Waste-gas problems are thereby dealt with more easily, and a more compact plant design is possible. Production processes vary both in the manner of bringing the two raw materials into contact and in the methods of removing the heat of reaction.
The reactor can be a packed column with a chlorosulfuric acid spray at the top and hydrogen chloride and sulfur trioxide entering at the bottom. In this case, the reaction and the heat removal both take place in one piece of equipment. Alternatively, it is possible to separate these steps by first mixing the components intensively in a separate mixer such as a mixing nozzle; the hot reaction product is then quickly cooled with cold chlorosulfuric acid in a packed column or other suitable unit. Cooling has also been suggested by means of a water-cooled condenser. In one modification of the process, the first product is chlorosulfuric acid which contains a small excess of sulfur trioxide; this is then cooled and saturated with hydrogen chloride in a bubble column. The off-gas is normally scrubbed, first with 98 % sulfuric acid and then with water.
Several patents describe the recycling of recovered hydrogen chloride and sulfur trioxide. The heat of formation of chlorosulfuric acid can be used to evaporate sulfur trioxide from low-percentage oleum. The sulfur trioxide then reacts with hydrogen chloride at sub-atmospheric pressure.
All the industrial routes to chlorosulfuric acid are based on the reaction of hydrogen chloride with sulfur trioxid.
Earlier processes made use of contact process gas which contains 6 – 7 % SO3, but today it is more usual to use pure sulfur trioxide. Waste-gas problems are thereby dealt with more easily, and a more compact plant design is possible. Production processes vary both in the manner of bringing the two raw materials into contact and in the methods of removing the heat of reaction.
The reactor can be a packed column with a chlorosulfuric acid spray at the top and hydrogen chloride and sulfur trioxide entering at the bottom. In this case, the reaction and the heat removal both take place in one piece of equipment. Alternatively, it is possible to separate these steps by first mixing the components intensively in a separate mixer such as a mixing nozzle; the hot reaction product is then quickly cooled with cold chlorosulfuric acid in a packed column or other suitable unit. Cooling has also been suggested by means of a water-cooled condenser. In one modification of the process, the first product is chlorosulfuric acid which contains a small excess of sulfur trioxide; this is then cooled and saturated with hydrogen chloride in a bubble column. The off-gas is normally scrubbed, first with 98 % sulfuric acid and then with water.
Several patents describe the recycling of recovered hydrogen chloride and sulfur trioxide. The heat of formation of chlorosulfuric acid can be used to evaporate sulfur trioxide from low-percentage oleum. The sulfur trioxide then reacts with hydrogen chloride at sub-atmospheric pressure.

The breakdown of chlorosulfuric acid production according to end use is as follows:
- Detergents 40 %
- Pharmaceuticals 20 %
- Dyes 15 %
- Crop protection 10 %
- Ion-exchange resins, plasticizers, and others 15 %

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

Joachim Maas/fritz Baunack: Chlorosulfuric Acid. Published online: 2000. 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.a07_017

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.