Fractions composition study of the pyrolysis oil obtained from sewage sludge treatment plant

In this work the parameters of Low Temperature Conversion – LTC were applied in a centrifuged sludge from a sewage treatment plant located in Rio de Janeiro, Brazil. Before the conversion, the sludge was dried and analyzed by TGA to observe its behavior with increasing temperature. The chemical composition of the crude pyrolysis oil was analyzed by FTIR, 1H NMR and GC–MS. The results showed that the oil is a mixture of hydrocarbons, oxygenated and nitrogenated compounds. Using a catalytic treatment it was possible to fractionate the oil where the predominant constituents were hydrocarbons showing that the cracking was effective. An important result was the difference between the calorific value of dry sludge (10 MJ kg−1), the pyrolysis oil (36 MJ kg−1) and one of the fractions separated by catalytic cracking (40 MJ kg−1) when compared with commercial diesel (45 MJ kg−1).