MECS® SolvR® Technology for Regenerative SO₂ Recovery



MECS® SolvR®  technology allows for the regenerative recovery of SO2  in single absorption sulfuric acid plant tail gas, Claus SRU tail gas SO2  recovery/recycling, carbon black and in other applications where it is not possible to recover SO2  directly as sulfur or sulfuric acid. 

An Energy Efficient SO2 Absorption Process with nearly Zero SO2 Emissions


SolvR® Technology employs an absorption solvent that is readily available, environmentally friendly and lower in cost than solvents used in other SO2  absorption processes. The technology can be integrated into new sulfuric acid plant designs  to achieve ultra low SO2 emissions and high energy recovery. In industries that produce a high volume, low SO2 content exhaust gas, SolvR® can be used to concentrate the gas stream prior to the sulfuric acid plant.

The SO2 recovered can either be liquefied, converted into sulfuric acid or converted into sulfur – all commercial grade products. The resultant cleaned gas has guaranteed SO2  levels of 20 ppm or less. In addition, the largest operating expense, steam, can be significantly reduced by using SolvR® energy recovery techniques.  


In all regenerative systems, oxygen reacts with the SO2 dissolved in the solvent to form sulfuric acid. The sulfuric acid in turn reacts with solvent constituents, degrading the performance and requiring occasional regeneration.  

With some technologies, the sulfuric acid reacts directly with the solvent, creating an undesirable waste and costly solvent losses. In contrast, MECS® SolvR® Technology uses an eco-friendly solvent that does not react with the sulfuric acid. A small fraction of the absorbed sulfur dioxide reacts with the oxygen typically present in tail gas leading to the formation of sodium sulfate which readily separated from the solvent. The aqueous sodium sulfate can then be discharged to the plant sewer or dried and transported as a solid waste to a municipal landfill. At a small incremental capital cost, this sulfate can also be recycled to the process for zero-liquid discharge.

In concentration/conversion plants such as for carbon black exhaust, the flow scheme is simplified as shown below.  

Sulfur burning acid plant Expand
No Objectionable Waste means Lower Cost and Environmental Compatibility

Benefits for MECS® SOLVR®Technology

  • Uses readily available, lower cost solvent 
  • Eco-friendly solvent 
  • Solvent does not react with sulfuric acid 
  • Produces aqueous sodium sulfate which can be readily separated 
  • Guaranteed SO2  emissions at 20 ppmv or less 
  • Lower operating costs due to low steam usage 
  • Simple, reliable operation over a wide range of SO2  concentrations 
Benefits for MECS® SOLVR®Technology

In some cases, the feed gas to the SolvR® plant may need additional conditioning and cooling prior to entering the absorber tower. In these cases, a DynaWave® reverse jet scrubber and gas cooling tower with Brink® mist eliminators or wet electrostatic precipitators can be installed upstream of the SolvR® plant depending of the level and species of the impurities in the gas stream.


For further information, download our SolvR® brochure