Recycling by pyrolysis of thermoset composites:: characteristics of the liquid and gaseous fuels obtained

A sheet moulding compound (SMC) of fibre-glass and ortho-phthalic polyester has been pyrolysed in a laboratory installation at 300, 400, 500, 600 and 700 degrees C for 30 min. Solid residues of 72-82 wt%, gas yields of 6-12 wt% and liquid yields of 9-13 wt% were obtained. No significant influence of temperature was observed over 400 degrees C, however, there certainly was influence under 400 degrees C, both in pyrolysis yields and in the composition and characteristics of the liquids and gases obtained. The pyrolysis liquids are a complex mixture of C-5-C-20 organic compounds, mainly aromatic and with numerous oxygenated compounds. They have high gross calorific values (34-37 MJ kg(-1)) and are non-polluting liquid fuels. About 40% weight of such liquids could be used as petrol and the remaining 60% could be mixed with fuel oils. The gas fraction produced is very rich in CO and CO2. Consequently, its gross calorific Values are rather low (13.9-16.4 MJ m(3) N); however, it can have energy source to self-sustain the process. (C) 2000 Elsevier Science Ltd. All rights reserved.