Physico-Chemical Effluent Treatment

Development of a technical process for the oxidation of biologically non-degradable waste water in supercritical water (Part 1)

The SUWOX process decomposes pollutants in supercritical water that are biologically hard to degrade. It is characterised by a concentric double pipe reactor to control corrosion, as well as by an operating pressure of 70 MPa, which means that waste water with high levels of salts can also be processed.

 

Summary

When decomposing pollutants using SCWO (supercritical water oxidation) processes, the reacting media, i.e. the pollutants and oxygen, are dissolved in the supercritical water within a liquid phase. There are no transport-impeding interfaces to multi-phase systems, resulting in very high oxidation rates. In addition, high conversion rates are achieved in small volumes within a completely closed system. 

In comparison with the wet oxidation processes established in current practice, SCOW processes offer savings potentials with regard to both investment and operating costs. However, problems are caused by the corrosion of container materials and blockages caused by salts. 

The aim of this project was to continue work on the previously developed, laboratory-scale SUWOX (supercritical water oxidation) process to render it ready for marketing and to overcome the above-mentioned problems by improving the process technology. 

Results: 

  • A SUWOX plant was used on a semi-industrial scale (approx. 100 litres of throughput per hour) to investigate real waste water streams from potential users in the photochemicals, biocide production, water-based paint and pharmaceutical production industries. For all tests, the degradation rates for organic pollutants were above 99%. 
  • The 70 MPa oxygen technology developed and successfully used qualifies for the development of new technical applications. Another spin-off product is the application of non-oxide ceramics as primary material for installation into pressure control valves. This means that corrosion and blockages can be 
  • controlled.

Project Participants

Implementing Institution

Forschungszentrum Karlsruhe GmbH

More Project Informations

Project title:  Development of a technical process for the oxidation of biologically non-degradable waste water in supercritical water (Part 1)

Project number:  02WA0030

Project period:  2000 - 2003

Project region:  Germany (Baden-Württemberg)

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Source: German National Library of Science and Technology Hannover (TIB)