Air Separation Technology . From 1910 onwards gas welding and gas cutting with acetylene/oxygen were used increasingly by industry and trade. The need for oxygen therefore increased sharply which led to AGA starting oxygen manufacture on Lidingö in 1914 and then in many other places in the world. The air's components, oxygen, nitrogen and argon are separated after being chilled down to a very low temperature (approximately -200°C) in an air separation column. The components of the air have then become liquid and can be separated using a distillation process.In the 1930s hospitals began to demand more oxygen since they were beginning to use more together with nitrous oxide and carbogen (oxygen containing about 5% carbon dioxide) in respiratory treatment, anesthetics and pain relief. In the second world war argon was used in large quantities for argon arc welding. In the 1940s another major application appeared for oxygen when ironworks started using the gas in their annealing and blast furnace processes. . In 1951 AGA built its first factory for liquid oxygen on Lidingö based on a German installation for V2 missile fuel. It was found that for large consumers it was necessary to transport oxygen in liquid form in tankers.