Four different coals were instantaneously introduced into a laboratory-scale pyrolysis chamber at various temperatures, and their devolatilization profiles were analyzed with respect to kinetics. The experimental setup consisted of a gas chromatograph (GC) with a pyrolysis unit, an empty column, and a detector. Detector signals were digitalized and stored for further handling. Normally, 1,024 values were sampled at 250 Hz. For deconvolving the true instantaneous devolatilization from the observed detector response, the residence time distribution was compensated for. An empirical model approach is developed to correlate the total devolatilization rates when instantaneously introducing a particle in a constant temperature environment. The model is also extended to pyrolysis application.