Different pyrolysis kinetics and product distribution of municipal and livestock manure sewage sludge

Thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry measurements were taken to examine the kinetic behavior and product distribution on the thermal and catalytic pyrolysis of different types of sewage sludge. Compared to livestock manure sewage sludge (LMSS), municipal sewage sludge (MSS) had larger ash (30.3%) and lower fixed carbon (7.9%) contents. The peak intensities for the 1st decomposition region (200-380 degrees C) on the derivative thermogravimetric curve of MSS were higher than those of LMSS. In contrast, the peak height in the 2nd temperature region (>380 degrees C) of MSS was lower than that of LMSS. The activation energy for the pyrolysis of MSS (Avg. 186.5 kJ/mol) was lower than that of LMSS (Avg. 263.4 kJ/mol) over the entire conversion range. MSS produced larger amounts of fatty acids and cholesterol than LMSS. The in-situ catalytic pyrolysis of MSS over HBeta using a pyrolyzergas chromatography/mass spectrometry also produced larger amounts of aromatic hydrocarbons than LMSS, suggesting that its better feedstock properties strongly influence the final product oil quality. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry were used to study the kinetic behavior and product distribution of thermal and catalytic pyrolysis of different types of sewage sludge. Municipal sewage sludge (MSS) has a lower activation energy and produces more fatty acids and cholesterol than livestock manure sewage sludge (LMSS). By using a different catalyst, the product distribution of MSS can be altered, increasing the yield of aromatic hydrocarbons.