Spherical microporous/mesoporous activated carbon from pulping black liquor

BACKGROUND: A simple and effective method with environmental and economic benefits has been developed to produce spherical lignin and spheroidal microporous/mesoporous activated carbon from pulping black liquor. RESULTS: Spherical lignin with regular size of about 100 nm was obtained at 90 °C after 8 h treatment at pH 2. Pyrolysis of spherical lignin was impregnated with H3PO4 producing spheroidal microporous/mesoporous activated carbon with high apparent Brunauer–Emmett–Teller (BET) surface area of 1972 m2 g−1 and high carbon content of 68.0 wt% at 700 °C with impregnation ratio of 1:7. CONCLUSION: The process was inexpensive, sustainable, environment‐friendly and suitable for large‐scale production.