One of Europe's leading viscose staple fibre producers, Kelheim Fibres GmbH in Bavaria, Germany, has decided to implement Topsoe's WSA technology for upgrading their off-gas treatment system. The WSA plant will eliminate hydrogen sulphide and carbon disulphide contained in the off-gases by converting these sulphur compounds into sulphuric acid. The off-gas volume treated is 30,000 Nm³/h, and 200 ton/day of acid is recovered.

Sulphuric acid is a material used in the production of viscose fibres, so in addition to the environmental effect, the recovery of sulphuric acid will entail considerable savings. The WSA plant is very energy efficient, and excess heat of reaction from the process is recovered in the form of high pressure superheated steam. The steam will be used in Kelheim Fibres’ power station, thus reducing fuel consumption to the benefit of both the economy and the environment.

The WSA plant at Kelheim Fibres GmbH will be implemented by Lenzing Technik GmbH, Austria, acting as main contractor. Topsoe is supplying all equipment and catalyst for the WSA process plant, and Lenzing Technik GmbH is responsible for various off-site installations, tie-in and erection.

The WSA process is a versatile and energy efficient process for converting sulphur compounds in off-gases into sulphuric acid. More than 50 WSA plants have been implemented or are under construction worldwide be Topsoe, and four of these are for the viscose fibre industry

For further information please contact Mr. Jens Laursen at jkrl@topsoe.dk.