The kinetic thermal behavior and gaseous pollutant emissions of co-combustion between paper sludge and oil-palm solid wastes with a full range of blending ratio were investigated via a thermogravimetric simultaneous analyzer coupled with a Fourier transform infrared measurements. Co-combustion paper sludge with oil-palm solid wastes created significant changes in the thermal behaviors. With the exception of 10O90P blend, the combustion process of other blended fuels could be distinguished into three individual stages. The 90O10P blend showed the highest comprehensive combustion index (S = 5.59 x 10(-07) min-2 degrees C-3) and the (dS/d(ratio)) reached the maximum at blended samples of 20O80P, these observations suggested the blending of paper sludge with oil-palm solid wastes improved the comprehensive combustion performance. Further analysis of the emission profiles of gaseous pollutants revealed that the co-combustion paper sludge and oil-palm solid wastes lead to a reduction in gaseous emissions (SO2, NO and CO2). Furthermore, co-combustion promoted the KCl of oil-palm solid wastes to convert into HCl in fuel gas, which could reduce the possibility of slagging, corrosion and fouling during co-combustion. The analysis results indicated 10-30% of paper sludge in the blends could be determined as the optimum ratio range for co-combustion paper sludge and oil-palm solid wastes. The nth order reaction model by the Coats-Redfern method was used to determine the kinetics parameters for the co-combustion of paper sludge, oil-palm solid wastes and their respective blended fuels. The analysis results showed that nth order reaction model could fit the co-combustion process very well. (C) 2014 Elsevier Ltd. All rights reserved.