Bad Soden, Germany,

Spectacular installation of an air separation plant

On time, spectacular and in the end a success. This was the highpoint in the installation of a production plant for air gases from the industrial gas specialist Messer. The most powerful crawler crane in southern Germany was brought specifically to Salzgitter to lift a 140-ton aluminium column 100 metres into the air for fitting into a 62 metre tall steel housing. Messer is investing approx. 50 million euros in the air separation plant on the site of Salzgitter Flachstahl GmbH. "We are sticking to our target of creating a reliable production basis for gases for northern and eastern Germany and hope that in doing so we will make a long-term contribution toward encouraging more companies to settle there," explains Stefan Messer, owner and CEO of the Messer Group.

Within the separation column of the air separation plant, ambient air is broken down into its principal components of oxygen and nitrogen using a state-of-the-art thermal separation process. The various properties from the gases enhance the quality of many products across all branches, or they make the manufacture of such products possible in the first place. For example oxygen is widely used to accelerate combustion processes such as in steel production. The properties of nitrogen, in contrast, cause the displacement of atmospheric oxygen, with nitrogen also being used for cooling processes.

On target: construction running to plan

On 7 May 2009 Messer laid the cornerstone for the production plant on the site of Salzgitter Flachstahl, a company belonging to Salzgitter AG. With its long-term projects – the contract has a 15 year term – the largest privately managed industrial gas producer is defying the economic crisis. In time prior to the onset of winter, Messer and its partners hoisted the topping-out garland for the new construction. From August 2010 Salzgitter Flachstahl GmbH will be supplied with industrial gases from the production plant for a period of 15 years. The air separation plant will feed up to 28,000 standard cubic metres of gaseous oxygen per hour into Salzgitter Flachstahl GmbH's distribution network. Messer can optionally supply the company with up to 40,000 standard cubic metres of nitrogen per hour in gaseous form. Messer will also produce liquid oxygen, nitrogen and argon for the local market.

The world's largest privately managed producer of industrial gases is investing up to a total of 160 million euros in constructing and expanding production in Germany. Messer is investing in total 700 million euros in order to give its customers in Europe and Asia independent and reliable supplies.

How air is separated

Air separation in a production plant for atmospheric gases is a purely physical process in which no chemical reactions occur. In the separation column, the heart of an air separation plant, the extremely cooled and compressed air trickles down in liquid form toward the ascending gaseous air. The liquid is stored on the column's sieve trays and vapour bubbles are passed through it. From the gas flow, oxygen, which has a higher boiling point, liquefies at its boiling point of minus 183 degrees Celsius. From the liquid droplets, nitrogen, which has a lower boiling point, evaporates at its boiling point of minus 196 degrees Celsius. Gaseous nitrogen therefore collects at the head of the separation column and liquid oxygen in the "sump". By evaporating the oxygen in the sump and adding liquefied nitrogen at the head of the column, the process is continued until the required purity is achieved.