Both the raw materials and the solid and liquid pyrolysis products obtained were thoroughly characterized using the following analytical techniques. The moisture and ash contents of the samples were determined by thermogravimetric analysis according to D3173-85 and D3174-82 ASTM standards respectively, and the elemental composition with an automatic CHN analyser. Method 5050 of the Environmental Protection Agency (EPA) of the United States was used for chlorine determination. The gross calorific value (GCV) was determined with an automatic calorimetric bomb. Additionally, pyrolysis liquids were also analysed by gas chromatography coupled with mass spectrometry detector (GC–MS). Concerning pyrolysis gases, they were analysed by means of a gas chromatograph coupled with a thermal conductivity and a flame ionization detectors (GC-TCD/FID). The GCV of the gases was theoretically calculated according to their composition and to the GCV of the individual components.