The SNOX™ process is an innovative process which removes sulphur dioxide, nitrogen oxides and particulates from flue gases. The sulphur is recovered as concentrated sulphuric acid and the nitrogen oxides are reduced to free nitrogen.
The process is based on catalytic reactions and does not consume water or absorbents. Neither does it produce any waste, except for the separated dust.
In addition the SNOX™ can handle other sulphurous waste streams. This is highly interesting in refineries, where e.g. H2S gas, sour water stripper gas and Claus tail gas can be led to the SNOX™ plant, and thereby investment in other waste gas handling facilities can be saved.
SNOX™ for flue gas desulphurisation
The SNOX™ process can be applied for treatment of flue gases from combustion of primarily high-sulphur fuels in power stations, refinery and other industrial boilers and for treatment of other waste gases containing sulphur compounds and nitrogen oxides.
The SNOX™ process is designed individually according to application and clients' needs.
SNOX™ market experience
The first full scale SNOX™ plant treating 1,000,000 Nm³/h flue gas from a 300 MW coal fired power plant at NEFO in Denmark was started up in 1991.
The largest SNOX™ plant in operation treats 1,200,000 Nm³/h flue gas from four petroleum coke fired boilers at the Agip Petroli SpA refinery in Gela, Sicily, Italy. Four more SNOX™ plants are in operation or under construction.
More than 80 other plants applying Topsoe's WSA process for handling of sulphurous off-gases with or without NOx removal have been contracted since 1980.
SNOX™ - ESAP for enhanced sulphuric acid production
In several places there is a need for both electric power and sulphuric acid. A cheap high-sulphur fuel such as petroleum coke can be used for power generation, while the flue gas is cleaned in SNOX™ plant under production of sulphuric acid. Elemental sulphur is fired in the SNOX™ plant in order to produce the desired amount of sulphuric acid.