The base catalyst LZ-2, which was the mixture of CaO and Na-NaOH/Al2O3 center dot 3H(2)O, was chosen for the decomposition of phenol tar to generate valuable chemicals. The selectivity of LZ-2 for dimethyl phenyl carbinol, a-methyl styrene dimer and cumenyl phenol was 100%, 100% and 98%, respectively. Under the optimum operating conditions of catalyst 2.5 wt%, operating temperature 603.15 K and decomposition time 3.5 h, decomposition ratios of cumenyl phenol and dimethyl phenyl carbinol were 98.7% and 99.97%, respectively. In addition, the experimental repeat-ability demonstrated that the total yield of valuable chemicals still reached 90.1% after the catalyst being used five times. Mass and energy balance indicated that the catalytic decomposition was a high potential for the recycling of chemicals from phenol tar. (c) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.