Pyrolysis process of coffee paper cup samples was investigated in a flow stream of nitrogen at different heating rates (10, 20, 30 and 40 degrees C min(-1)), using thermo-analytical techniques. It was found that second pyrolysis stage can be described by Sestak-Berggren (SB) autocatalytic model, with mechanism function f(alpha) = alpha(0.011)(1 - alpha)(1.459). Based on analysis of SB kinetic exponents (designated by M and N), it was found that second pyrolysis stage is mainly controlled by chemical process, involving reactions with reactionorder (n) higher than unity. Applying specific statistical analysis, in order to obtain precise distribution of reactivity, the discrete (binomial) distribution has shown that there are two important areas of current distribution for corresponding energy outcomes, within the apparent activation energy as random variable. The first "concentration" area of energy outcomes corresponds to start of chain end depolymerization reaction forming levoglucosan at high enough temperature region, while second "concentration" area of energy outcomes includes occurrence of macro-radicals in liquid phase propagate with radical addition on unsaturated C-C bonds, with cross-linking and formation of small chemical species. It was found that further elevating of temperature (above 340 degrees C), will leads to fact that rate of tar-forming reactions increases and formation of char decreases. (c) 2014 Elsevier Ltd. All rights reserved.