The present work comprehensively addresses various experimental methods reported in the literature and substantiates the use of two-stage activation process with semi-carbonization stage up to 200degreesC as first stage followed by an activation stage at a desired temperature, for production of activated carbon from carbonaceous precursors using phosphoric acid. Efforts are made towards developing a high surface area activated carbon from rubber wood sawdust by a two-stage activation process with phosphoric acid as the activating agent. Experiments are conducted in a lab scale muffle furnace under static conditions in a self-generated atmosphere covering process parameters such as impregnation ratio, carbonization time and temperature. The precursor material with impregnation agent is exposed straightaway to semi-carbonization and activation temperature unlike following the specific temperature progression as reported in the literature. The process parameters are optimized based on product yield and iodine number. Semi-carbonization at 200degreesC for 15 min followed by activation at 500degreesC for 45 min with impregnation ratio of 1.5 yielded a product with iodine number 1096 which corresponds to a BET surface area of 1496 m(2)/g with the product yield of 35% and activation agent recovery of 90%. (C) 2003 Elsevier Ltd. All rights reserved.