Production of Phenolic Compounds from Catalytic Oxidation of Kraft Black Liquor in a Continuous Reactor

Black liquor is a side stream from the pulp and paper industry containing lignin other organic inorganic materials. Catalytic alkaline oxidation of black was carried out employing CuO/TiO2 catalyst in trickle-bed reactor mild reaction conditions (150–200 °C, 80 bar) short contact times (4–9 min). The effects temperature, time, presence were investigated. In our best operating conditions, i.e., 200 °C 4 min conversion complete, phenolic monomers obtained (maximum total yield 6.2 wt %), including vanillin 3.3 %). Vanillin represented 53 % monomers. At longer times, degradation compounds observed. application continuous reactor, allowing limiting reactions, particularly appropriate for this reaction. productivity 936 g m3 h–1.