Analysis through gas chromatography of the products obtained from slow pyrolysis applied to Russian feedstock

Slow pyrolysis experiments were performed at 500 °C on Russian feedstock (hydrolysis lignin, peat, mixed sewage sludge, and pine and spruce woods, for comparison). The pyrolysis products were analyzed through gas chromatography, and more than 130 components were identified and grouped according to their chemical family. A qualitative analysis of the pyrolysis products showed that the highest amount of molecules (more than 40%) released during the pyrolysis of hydrolysis lignin belongs to the phenol chemical family. They result from the lignin degradation. The peat pyrolysis led to a large amount (more than 50%) of sugars. The molecules detected during the pyrolysis of the mixed sewage sludge are similar to that of the spruce sample and almost the same as that of the pine sample, because the selected sewage sludge is a mixture of municipal and industrial waste from pulp and paper industry. Comparisons between the data obtained for these Russian feedstock and that of the literature concerning quite similar materials exhibit differences which may be the consequence of the feedstock and of the experimental conditions.