The CANSOLV SO2 Scrubbing System controls emissions and captures additional by-product value from the SO2 emitted in various flue gas streams, such as those generated by fluidised catalytic cracking units, process heaters and boilers, sulphur plants and spent acid regeneration units.
The SO2 can be recycled to the sulphur recovery unit to produce marketable sulphur or it can be converted to sulphuric acid in a sulphuric acid unit and sold into acid markets.
Licensed units treating gas flow rates from 4,000 to 486,000 Nm3/h and SO2 concentrations from 800 to 12,000 vppm are operating successfully, and units are under construction to process up to 1,750,000 Nm3/hr of flue gas.
SO2 emissions below 20 ppmv can be achieved with base design configuration, and with minimal effluent production.
Moreover, the system has been designed for reliability: five years’ uninterrupted run time has been achieved.
In certain applications, it can also help to enhance margins.
For instance, in sulphur recovery unit applications, capacity can be increased by over 12%.
Moreover, marketable by-products are recovered; high-quality SO2, sulphur and sulphuric acid and there is no solid waste.
CANSOLV SO2 Scrubbing System Benefits
- High performance – sulphur recovery efficiency of 99.9+%
- SO2 emissions as low as 10 ppmv
- Varying inlet SO2 concentrations delivered as a continuous and steady product stream through load-leveling
- Lower operating costs than traditional FGDs
- Low Capex cost sensitivity to changing sulphur content in fuel or process raw materials
This patented technology uses an aqueous amine solution to achieve highly efficient, selective absorption of SO2 from flue gas. The key process steps are:
- Feed gas is quenched and saturated in a circulated water pre-scrubber.
- The gas contacts the lean amine solution in a counter-current absorption column.
- SO2 is absorbed and the treated gas exits the absorber to atmosphere.
- SO2-rich amine from the absorption column is pumped through a lean–rich amine heat exchanger for energy recovery and on to the regeneration column.
- Steam stripping regenerates the lean amine solution, and the SO2 is recovered as a pure, water-saturated product.
- Lean amine is pumped from the stripper reboiler to the absorption column through the lean–rich amine heat exchanger and the lean amine cooler.
- By-product SO2 is directed to by-product management systems and is converted to various products, including liquid SO2, sulphuric acid and elemental sulphur.