COMPARATIVE STUDY OF KRAFT WHITE LIQUOR AND RECOVERED WHITE LIQUOR FROM THE ELECTRO-ELECTRODIALYSIS PROCESS.

Abstract

In the chemical recovery department of pulp and paper mills, the cooking liquor is regenerated by adding fresh lime (CaO) to a solution of green liquor (rich in sodium carbonate, Na2CO3), where calcium carbonate (CaCO3) precipitates and leaves NaOH in solution (causticizing process). CaO is then regenerated from precipitated CaCO3, a process that consumes much energy and is hazardous to the environment. In the current study, green liquor was electrolyzed into a caustic solution using a cation exchange membrane (CEM) positioned between two electrodes, and the strength properties of paper made using conventional white liquor and white liquor obtained through the EED procedure are compared.