Doctor of Philosophy
Chemical and Biochemical Engineering
Xu, Chunbao (Charles)
Bio-oil, produced from bio-feedstocks by thermochemical conversion technologies (e.g., pyrolysis or direct liquefaction), can be renewable replacement for petroleum for energy and chemical production. However, bio oil has high oxygen content, low stability, and low heating value. Thus, upgrading of bio-oil is necessary to remove the oxygen and make it a suitable substitute for conventional liquid transportation fuels or for value-added bio-based chemicals. Oxygen in a bio-oil can be removed by catalytic cracking or hydro-de-oxygenation to the form of H2O, CO and CO2 in the presence of a catalyst.
The overall objective of this PhD project was to develop novel technical solutions to production of monomeric aromatics/phenolics from hydrolysis lignin (HL) – a residue from cellulosic ethanol plants, for potential applications as fuels, fuel additives and chemicals. In this PhD thesis work, a catalytic fast pyrolysis (CFP) reactor system was in-house designed and constructed, and some novel zeolite-based solid acid catalysts with tailored strengths of acidity and improved resistance to carbon/coke deposition, such as acidified ZSM-5 catalysts, were developed to achieve a high yield (151 mg/g-HL) at a mild pyrolysis temperature (450°C). In addition, hydrothermal liquefaction (HTL) – an emerging technology for biomass conversion under milder temperature (at 350°C for 30 min) was employed to produce biocrude from hydrolysis lignin (HL) in water-ethanol (50:50, v/v) mixture with hematite ore as the catalyst. More importantly, the phenolics of the HL-derived biocrude was extracted and the phenolic extracts were used a bio-substitute to phenol for the synthesis of bio-phenol formaldehyde (BPF) resoles as wood adhesives. The dry bonding strengths of BPF resoles prepared with the phenolic extracts are higher than that of the BPF resoles prepared with the whole biocrude oils and the neat PF resole.
Paysepar, Hooman, "Production of monomeric aromatics/phenolics from hydrolysis lignin (HL) by catalytic fast pyrolysis and hydrothermal liquefaction" (2018). Electronic Thesis and Dissertation Repository. 5381.