Heating rate effects on pyrolysis, gasification and combustion of olive waste

Abstract

Pyrolysis, combustion and gasification of solid residues from olive oil processing were investigated. The raw solid residue (RS) contains moisture (21.5%) and residual oil (6.4%). Therefore, from RS, raw samples without water (RSWW) and without oil (RSWO) were produced. Thermal analyses of samples were performed at different heating rates over a temperature range of 150–1050 °C. Pyrolysis behavior of the sample was studied in an argon atmosphere, whereas the combustion and gasification studies were conducted in oxygen and steam atmospheres, respectively. The effects of heating rate on the reaction rate and gas evolution were analyzed. Thermal degradation of RS showed that nearly 90% of the conversion occurred at below 700 °C. Gases produced in the three processes mainly consisted of hydrogen, hydrocarbons and carbon oxides. Alcohols and sulfur compounds were also detected in the temperature range of 300 to 500 °C for pyrolysis. Activation energies were determined from non-isothermal multi-heating rate thermogravimetric measurements. The variation in gas evolution was observed between the samples during gasification.

Keywords:

• Olive waste
• TGA-MS
• heating rate
• pyrolysis
• gasification
• combustion
• kinetics

Funding

The authors wish to acknowledge the funding support from the Region Centre Val de Loire, project code VERA-P2 (no. 2015-00099702).

Disclosure statement

No potential conflict of interest was reported by the authors.