Study of co-pyrolysis of olive kernel with waste biomass using TGA/DTG/MS

Highlights: • TG/DTG/MS analysis of pyrolysis of three waste biomass materials and their mixtures. • Satisfactory calorific value of light gases from pyrolysis, low water content. • Strong synergy effects of co-pyrolysis on CO and H₂ production. • More or less additive behavior for CO₂, hydrocarbons, NH₃, HCN, HCl production. • No significant effect of co-pyrolysis on char, tar yield and heating value of gases. The evolution of the pyrolysis products of olive kernel, a municipal solid waste fraction and a sewage sludge was analyzed qualitatively and quantitatively, using a properly developed and calibrated system of coupled thermogravimetry-mass spectrometry (TG/MS). The TG/MS profiles of the volatile products were also related to the pyrolysis thermograms, after their deconvolution which was performed using an independent parallel reaction kinetic model. The results from the co-pyrolysis of two mixtures of olive kernel with the municipal waste fraction and with sewage sludge at 7:3 mixing ratio revealed strong synergy effects on the production of CO up to 600 °C and the production of H₂ at elevated temperatures. Other compounds were found to present slight synergistic (hydrocarbons up to C₃, HCl, HCN) or additive behavior (CO₂, H₂O, NH₃). No significant effect of co-pyrolysis on the anticipated quantities of char, tar and on the heating value of the pyrolysis gases of the mixtures was observed.