Low-temperature co-pyrolysis behaviours and kinetics of oily sludge: effect of agricultural biomass

Pyrolysis is potentially an effective treatment of oily sludge for oil recovery, and its kinetics and efficiency are expected to be affected by additives. In the present study, the pyrolysis parameters, including heating rate, final pyrolysis temperature, and pyrolysis time of oily sludge in the presence of agricultural biomass, apricot shell, were systematically explored. As a result, maximum oil recovery is achieved when optimizing the pyrolysis conditionas15 K/min, 723 K, and 3 h for heating rate, final pyrolysis temperature, and pyrolysis time, respectively. Thermogravimetric experiments of oily sludge samples in the presence of various biomasses conducted with non-isothermal temperature programmes suggest that the pyrolysis process contains three stages, and the main decomposition reaction occurs in the range of 400-740 K. Taking Flynn-Wall-Ozawa analysis of the derivative thermogravimetry and thermogravimetry results, the activation energy (E_a) values for the pyrolysis of oily sludge in the presence and absence of apricot shell were derived to be 35.21 and 39.40 kJ mol^-1, respectively. The present work supports that the presence of biomass promotes the pyrolysis of oily sludge, implying its great potential as addictive in the industrial pyrolysis of oily sludge.