The development of the Topsoe WSA process for removal of sulphur compounds from flue gases and production of sulphuric acid began in the late 70's and it builds on Topsoe’s extensive experience from the sulphuric acid business and long-term commitment to development of catalysts and process technology. Major research areas are SO2 oxidation over sulphuric acid catalysts and acid condensation.
Fundamental studies
The ability to condense sulphuric acid vapours to produce concentrated sulphuric acid without emission of acid mist is a unique feature of the WSA process which has been achieved by comprehensive experimental and theoretical studies at Topsoe.
During cooling of a gas containing sulphuric acid vapours, spontaneous homogeneous nucleation, heterogeneous condensation and wall condensation occur simultaneously. In order to develop and perfect the WSA condenser, we have studied these fundamental mechanisms of aerosol condensation and the competition between them thoroughly in lab scale investigations.
Process development and optimisation
Pilot and industrial scale testing combined with detailed mathematical modelling of the WSA condenser are used for investigation of the effect of condenser design and operating conditions on condenser performance in order to establish robust criteria for design and process control.
Another focus area of our development work is perfection of the WSA glass tube technology and continuous improvement of construction materials. The latter requires our expertise on materials testing in the harsh environments of sulphuric acid plants.
In order to utilise the full potential of the WSA technology we use innovative flow sheeting in Topsoe’s proprietary calculation tools for optimisation for different industrial applications. One of the drivers for this development is the increased global focus on energy consumption and CO2 emissions which calls for maximum heat recovery as valuable high pressure steam.
The SNOX™ process
For removal of both sulphur and nitrogen oxides from flue gases Topsoe has developed the SNOX™ process which combines WSA and SCR DeNOx for optimum integration in power plants.