Relevant Degree Programs
Complete these steps before you reach out to a faculty member!
- Familiarize yourself with program requirements. You want to learn as much as possible from the information available to you before you reach out to a faculty member. Be sure to visit the graduate degree program listing and program-specific websites.
- Check whether the program requires you to seek commitment from a supervisor prior to submitting an application. For some programs this is an essential step while others match successful applicants with faculty members within the first year of study. This is either indicated in the program profile under "Requirements" or on the program website.
- Identify specific faculty members who are conducting research in your specific area of interest.
- Establish that your research interests align with the faculty member’s research interests.
- Read up on the faculty members in the program and the research being conducted in the department.
- Familiarize yourself with their work, read their recent publications and past theses/dissertations that they supervised. Be certain that their research is indeed what you are hoping to study.
- Compose an error-free and grammatically correct email addressed to your specifically targeted faculty member, and remember to use their correct titles.
- Do not send non-specific, mass emails to everyone in the department hoping for a match.
- Address the faculty members by name. Your contact should be genuine rather than generic.
- Include a brief outline of your academic background, why you are interested in working with the faculty member, and what experience you could bring to the department. The supervision enquiry form guides you with targeted questions. Ensure to craft compelling answers to these questions.
- Highlight your achievements and why you are a top student. Faculty members receive dozens of requests from prospective students and you may have less than 30 seconds to peek someone’s interest.
- Demonstrate that you are familiar with their research:
- Convey the specific ways you are a good fit for the program.
- Convey the specific ways the program/lab/faculty member is a good fit for the research you are interested in/already conducting.
- Be enthusiastic, but don’t overdo it.
G+PS regularly provides virtual sessions that focus on admission requirements and procedures and tips how to improve your application.
Graduate Student Supervision
Doctoral Student Supervision (Jan 2008 - Mar 2019)
Ethanol produced from lignocellulose is one of the most promising biofuels. However, the technology to produce lignocellulosic ethanol is still under development and needs to be improved to become economically viable. Enzymatic hydrolysis is one of the most expensive process stages, primarily due to high enzyme costs. Consequently, two cost reduction strategies were studied: optimization of hydrolysis conditions and enzyme recycle by adsorption. To optimize enzymatic hydrolysis, the changes in concentration of cellulases during the reaction must be determined. Protein concentration changes under hydrolysis conditions for Celluclast 1.5L and Novozyme 188, were studied in the absence of substrate. Novozyme 188 protein concentration decreased by 55 to 64% at 50°C after 92 h. A model describing Novozyme 188 protein concentration changes was developed and used to determine free and adsorbed cellulases concentrations. Glucose and xylose yields (58 to 89% conversion) during enzymatic hydrolysis were modeled as a function of enzyme loading, time, lignin content and solids concentration. The proposed model successfully describes hydrolysis of substrates with different lignin contents, linking pretreatment and hydrolysis. The effect of lignin content, enzyme loading and hydrolysis time on enzyme recovery was evaluated, achieving 0 to 35% cellulases recycled. A mass balance of the enzyme recovery process was built and used to achieve a uniform production of sugar. Based on experimental data and the proposed models, the production of ethanol with and without enzyme recycling was simulated in AspenPlus. The ethanol production process at different operating conditions was economically evaluated. The economic analysis showed that raw material expenses determine production costs, where biomass, caustic and enzyme expenses are the major contributors to the operating cost. The lowest production costs ($1.86 and $2.13/ kg ethanol) were obtained at low enzyme loadings and mild pretreatment conditions. Sugar losses at severe pretreatment conditions have a significant negative effect on production costs: severe conditions increased production cost by 18 to 23%. Therefore, optimal hydrolysis conditions must be determined considering the entire process. The implementation of the enzyme recycling process decreased production costs up to 14% depending on operating conditions, demonstrating the potential benefits of the enzyme recycling technology.
Master's Student Supervision (2010-2017)
The challenges of upgrading pyrolysis oil to transportation fuel limit the economic viability of biomass pyrolysis. Therefore, this dissertation investigated partial oxidation of pyrolysis oil to produce value-added chemicals. Two model compounds, acetic acid (AcOH) and acetaldehyde (AcH) were selected for gas phase oxidation trials. Thermal oxidation of AcOH emphasized AcOH’s refractory nature as the maximum conversion of AcOH was less than 6% at 350 ⁰C at 1 atm with GHSV of 2000 h-¹. AcH was more reactive; conversion of AcH was approximately 40% under identical conditions. Thermal oxidation of both compounds produced only carbon dioxide (CO₂). Although the true reaction mechanism of AcH thermal oxidation could not be determined, the activation energy was calculated to be between 47.1±0.55 kJ/mol and 55.2±0.6 kJ/mol. Catalytic partial oxidation (CPO) of AcOH and AcH was examined using vanadium pentoxide supported by titanium oxide (V₂O₅/TiO₂). Conversion of CPO of AcOH was slightly higher than thermal oxidation but produced only CO₂. CPO of AcH generated AcOH, a desirable product, as well as formic acid (FA), carbon monoxide (CO) and CO₂, suggesting that multiple reactions occurred. However, the selectivity to AcOH was relatively low (43% at 175 ⁰C, GHSV=20000 h-¹, 2.4V/TiO₂). The selectivity of AcH to AcOH was improved by adjusting temperature, adopting higher vanadium (V) loading catalysts, and increasing oxygen (O₂) concentration. At 200 ⁰C, GHSV=20000 h-¹, and using 6.9V/TiO₂, the selectivity to AcOH increased to 70%. Constant selectivity of all products with respect to residence time indicates the reactions are likely parallel. The rate constant for AcH CPO was calculated assuming an overall 1st order reaction. The linearized Arrhenius law yielded an activation energy of 43.9 kJ/mol for the overall AcH CPO reaction. Simultaneous CPO of AcH and AcOH was also examined. The conversion of AcH in the mixture was similar to the conversion of CPO of AcH alone. This study demonstrated the feasibility of producing AcOH via CPO of AcH. The viability of partial oxidation of pyrolysis oil must be confirmed using model compounds with more complex functional groups and pyrolysis oil.