Evaluation of co-pyrolysis petrochemical wastewater sludge with lignite in a thermogravimetric analyzer and a packed-bed reactor: Pyrolysis characteristics, kinetics, and products analysis

Abstract

Co-pyrolysis characteristics of petrochemical wastewater sludge and Huolinhe lignite were investigated using thermogravimetric analyzer and packed-bed reactor coupled with Fourier transform infrared spectrometer and gas chromatography. The pyrolysis characteristics of the blends at various sludge blending ratios were compared with those of the individual materials. Thermogravimetric experiments showed that the interactions between the blends were beneficial to generate more residues. In packed-bed reactor, synergetic effects promoted the release of gas products and left less liquid and solid products than those calculated by additive manner. Fourier transform infrared spectrometer analysis showed that main functional groups in chars gradually disappeared with pyrolysis temperatures increasing, and H₂O, CH₄, CO, and CO₂ appeared in volatiles during pyrolysis. Gas compositions analysis indicated that, the yields of H₂ and CO clearly increased as the pyrolysis temperature and sludge blending ratio increasing, while the changes of CH₄ and CO₂ yields were relatively complex.

Keywords: Co-pyrolysis; Lignite; Products analysis; Sludge; Synergetic effects.