Molten Salt Oxidation

Molten salt oxidation breaks down organic constituents through oxidation more than by pyrolysis, although some pyrolysis may take place. The high temperatures (on the order of 900 °C) are sufficient to pyrolyze most organic compounds of concern and although there is oxygen present, it must diffuse through the molten salt. So in the short term, the compounds might pyrolyze, but eventually the oxidation takes place and the results are the same as those produced by incineration. There is no flame in MSO, however.

Carbon in the waste organics is converted to CO2. Hydrogen goes to H2O; chlorine goes to HCl, sulfur to SO2, and nitrogen to NO or NO2. Because there is no flame, the extremely high local temperatures of incineration processes are not present, and the production of NOx from air constituents (“burned air") does not occur.

An item of concern when chlorine-containing wastes are incinerated is the production of dioxin. Tests on MSO processes show extremely low levels of dioxin emissions as the chlorine is retained by the salt.

A common salt is sodium carbonate although other salts can be employed. MSO is especially appropriate for wastes with inorganic salts mixed in with the organic waste.

MSO has been tested for waste streams classified as hazardous, radioactive, and mixed. A side benefit in some processes is the conversion of hazardous salts to more benign salts. If the waste contains water, evaporation can occur, and the process designer often appreciates this as it gets rid of the moisture.