Method of recovering chemicals

Abstract

A method of treating waste liquors which comprise organic compounds, in order to recover chemical compounds or to recycle chemicals. In the present method, the sodium-based waste liquor, which comprises organic compounds that are sourced from lignocellulose, is subjected to partial wet oxidation, in order to produce organic sodium salts, in which case the partial wet oxidation is carried out in conditions where at least part of the lignin is simultaneously precipitated. The precipitated filtrate or lignin is subjected to further processing. Most suitably, the organic sodium salts, such as Na acetate, which are generated in the partial oxidation of the waste liquor, are also subjected to further processing, in which case it is possible, from the lignin and the organic sodium salts, to efficiently produce compounds which as such are already of sufficient quality as chemicals, or which as gases are suitable for further processing, for instance for production of fuels.