Saccharina japonica can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics of S. japonica were investigated using a thermogravimetric analyzer. Most of the materials decomposed between 200 degrees C and 350 degrees C at heating rates of 10-20 degrees C/min. The apparent activation energy increased from 102.5 kJ mol(-1) to 269.7 kJ mol(-1) with increasing pyrolysis conversion. The kinetic parameters of S. japonica pyrolysis were determined using nonlinear least-squares regression of the experimental data assuming first-order kinetics. The kinetic rate constants indicated that the predominant reaction pathway was B (bio-oil) to C (gas; C-1-C-4), rather than A (S. japonica) to B (bio-oil) and/or to C (gas; C-1-C-4). The proposed lumped kinetics of S. japonica pyrolysis offers a guide for the scale-up of the process at the research and industrial level. (C) 2012 Elsevier Ltd. All rights reserved.