Thesis Archive
Hydrothermal and solvolysis liquefaction of wet algal biomass for the production of bio-oil
Chua-Unsu, Audrey Gayle Alexis Y.
Abstract:
As the demand for fossil fuels continues to rise to cope with energy demand, renewable biomass sources are being studied as alternative resources for energy production. One such biomass is algae. Studies on thermochemical conversion techniques such as liquefaction, torrefaction, and pyrolysis applied on algal biomass have been studied for its conversion to biogas, bio-oil, and biochar. In order to make these techniques commercially viable, there is a need to understand the degradation kinetics for the design of optimized reactors. Thermogravimetric analysis (TGA) is a simple technique that may be used to determine the kinetics of pyrolysis. As such, TGA was performed on the algal biomass lablab to determine the activation energy and pre-exponential factor of its pyrolysis using the Kissinger-Akahira-Sunose (KAS) method, the simplified Distributed Activation Energy Model (DAEM), and the multiple parallel reaction model. For the three studies, the activation energies were determined to be 130.50kJ/mol, 112.46kJ/mol, and 64.09kJ/mol, respectively, while the pre-exponential factors were determined to be 2.56x13s-1, 2.85x1033s-1, and 872.91s-1, respectively. The three models gave fit qualities with average values of 1.03%, 82.49%, and 85.66% for KAS, DAEM, and multiple parallel reaction model, respectively. In this study, the lablab was also characterized and determined to contain 6.76% carbohydrates, 3.36% lipids, 2.43% proteins, 77.53% ash, and 3.48% moisture. The composition of the lablab explained why a wider peak was present at 300°C-400°C as compared to those found at 400-500°C and 500°C.
Adviser:
Madrazo, Cynthia F.
Bungay, Vergel C.