Hydropyrolysis of Lignin using Pd/HZSM-5 Oliver D. Jan Chair of the Supervisory Committee:Dr. Fernando Resende
School of Environmental and Forest SciencesThe aim of this work was to study the formation of cycloalkanes from hydropyrolysis of lignin with HZSM-5 and Pd/HZSM-5 catalysts. We observed that palladium supported on HZSM-5 catalyzed hydrogenation and deoxygenation reactions that converted phenolic compounds into aromatic hydrocarbons and cycloalkanes. This study analyzed the effect of the catalyst-to-lignin ratio, H 2 partial pressure, and temperature on the yields of hydrocarbons with HZSM-5 and Pd/HZSM-5. Pd/HZSM-5 produced 44% more aromatic hydrocarbons than HZSM-5 at a catalyst-to-lignin ratio of 20:1, 650ºC, and a constant H 2 partial pressure of 1.7 MPa. The presence of palladium led to significant difference in yields only at 1.7 MPa H 2 partial pressure.In both the in-situ and ex-situ experiments conducted, hydropyrolysis temperature played a substantial role in the equilibrium conversion of hydrogenation reactions that led to cycloalkanes directly from lignin.iv Dedication This thesis is dedicated to my family for all their love and support v Acknowledgements
We report a study of the catalytic reactions of ethylene oligomerization over nickel impregnated in aluminum silicate using subcritical and supercritical media. We found the BET surface area decreases with increasing nickel loading, indicating the deposition of NiO particles in the catalyst surface. We compared the performance of the NiBEA catalyst with the protonated form of the commercial support used during the preparation and showed that, although the protonated form promotes the oligomerization of ethylene, the corresponding oligomers do not desorb from the catalyst surface. Conversely, the introduction of nickel in the catalyst facilitates the desorption of the oligomers. Additionally, we used FTIR and GC-MS/FID to characterize the adsorbed and desorbed oligomers, and develop reaction pathways for the ethylene oligomerization over the NiBEA catalyst. We found that both adsorbed and desorbed oligomers are aliphatic, and the non-desorbed products constitute the coke. Additionally, we found that pressure and temperature both increase the oligomerization and desorption rates of adsorbed oligomers. Under
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