Evolution of gases from the pyrolysis of modified almond shells: effect of impregnation with CoCl2

Thermogravimetry/mass spectrometry (TG/MS) was applied to seven different almond shell samples treated by different methods. The samples were prepared after different acid and basic treatments, and impregnation with CoCl2. The samples were thermally degraded in a nitrogen atmosphere using healing rates of 20 and 40 degrees C min(-1). The weight loss and the evolution profiles of the thermal decomposition products of molecular mass less than 100 were monitored showing the influence of the different treatments applied to the almond shells. The production of compounds such as hydrogen, water, 2-furaldehyde and chloromethane are enhanced by the impregnation with cobaltum chloride. The treatments applied alter the structure of the almond shells either favoring or preventing the formation of various compounds. (C) 1997 Elsevier Science B.V.