Increased aromatics production by co-feeding waste oil sludge to the catalytic pyrolysis of cellulose

In this study, the use of oil sludge as the co-feeding feedstock on the catalytic pyrolysis of cellulose over various catalysts, such as Ni/HZSM-5, HZSM-5, HBeta, HY, and Al-MCM-41, was attempted for the first time. To know the catalytic co-pyrolysis effect, thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry measurement were utilized. Thermogravimetric analysis results indicated that Ni/HZSM-5 led to the lowest apparent activation energy (97.6 kJ/mol), followed by HY, HBeta, HZSM-5, and Al-MCM-41, suggesting the effective role of Ni providing the additional cracking and benzene, toluene, ethylbenzene and xylenes (BTEXs) formation. In addition, BTEXs production amount analyzed by pyrolyzer-gas chromatography/mass spectrometry was also highest by the use of Ni/HZSM-5 due to its proper pore size of HZSM-5 on BTEXs formation and additional effect of Ni. The experimental BTEXs yields on the catalytic co-pyrolysis of cellulose and oil sludge were higher than their theoretical values over all catalysts, suggesting their synergy effect. The highest synergistic effect was also achieved when 1/3 of cellulose/oil sludge mixture was applied as the feedstock.