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

The ability to carry out pyrolysis of entire wood chips and rods instead of small particles would be of great value for mobile pyrolysis units, because of the large possible savings in grinding costs (7-9 % of total process costs). With this goal in mind, we designed and constructed a novel lab-scale ablative reactor for fast pyrolysis of entire wood chips and even wood rods, converting those directly into a high yield of bio-oil for the first time. The bio-oil yield from fast pyrolysis of wood chips (10 × 20 mm) was as high as 60 wt. %, similar to that from wood crumbles (2 × 2 mm). Additionally, the yield and composition of bio-oil from ablative pyrolysis were in the same range as those obtained from a fluidized bed reactor using < 1 mm particles, with the small differences (slightly lower yield and HHV, and higher water content) attributed to the longer vapor residence times in the ablative reactor, which promote secondary reactions. We modeled the heat transfer characteristics of this semi-batch system, and comparison with experimental measurements confirmed that radiation from the hot components does not significantly decompose the wood prior to direct contact with the hot metallic surface in ablative pyrolysis. The findings of this work have the potential to lead to new developments for small-scale, mobile pyrolysis units for the disposal of forest residues.

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In this work, a flow photoreactor was designed and set up using low-cost and recyclable parts to develop chemical treatments based on advanced oxidation processes (AOP) of highly colored textile wastewater. To evaluate this sustainable system´s efficiency, we investigated and compared the performance of three types of destructive methods (UV/H2O2, Fenton, and photo-Fenton) on the decolorization of aqueous solutions of Reactive Black 5 dye (RB5). We also analyzed the effect of the oxidant and dye concentrations on the rate of color removal in each one of the three methods. The results showed that, regardless of the initial operating conditions, the photo-Fenton process achieved the highest degradation rates, particularly when the highest ratio between the oxidant and dye concentrations was used ([H2O2]: [RB5] = 24.5 mg L-1: 25 mg L-1), leading to complete color removal within only 10 minutes of reaction. With the same initial condition, the Fenton and UV/H2O2 processes were also capable of removing the color entirely, even though they demanded more extended runs of 25 min. and 45 min., respectively. The effect of pH on the decolorization by the photo-Fenton process was also investigated, showing the same high performance at pHs 3 and 4. The degradation profile achieved by the photo-Fenton treatment was appropriately fitted by a pseudo-first-order kinetic. The non-expensive photoreactor proved to be quite useful for the degradation of the RB5, mainly when this azo dye underwent the photo-Fenton process.