Potential value added applications of black liquor generated at paper manufacturing industry using recycled fibers

Characterization of neutral sulphite semi-chemical black liquor (NSSCBL), sampled from paper manufacturing process that uses recycled fibers as primary feedstock, was carried out for potential bioenergy and biomaterial applications. Physico-chemical characteristics including inorganic elements content, thermogravimetric analysis, GC/MS, and FT-IR are presented. The black liquor of the recycled fibers in the manufacturing process revealed unique characteristics in terms of chemical composition profile compared to the black liquor originating from regular pulp and paper industries. The major findings include the presence of chemical compounds, from a non-plant origin, such as derivatives of hexanedioic acid in significant quantities. The favorable biofuel characteristics of this black liquor are: neutral pH, a higher volatile content, and HHV. The recycled paper NSSCBL can be a good candidate for biomaterial and biofuel applications.