Date of Award:

2015

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Biological and Irrigation Engineering

Advisor/Chair:

Foster Agblevor

Abstract

Reports indicate that the worldwide energy consumption and fossil fuel energy production level will have an opposite trend in the coming two decades. The former will continue to increase while the later will decrease. Therefore, additional sources of energy need to be developed. Field pennycress (Thlaspi, arvense L.) has been found to be an ideal source of energy because it has prolific yield and has no value as food. We demonstrated conventional and catalytic fast pyrolysis of whole pennycress biomass in a fluidized bed reactor. Characterization studies on field pennycress showed that the biomass had a potential to be converted to energy-rich bio-fuel. Thermogravimetric and kinetic study on field pennycress provided vital information on the degradation behavior of the feedstock. A parametric study was conducted on conventional rapid pyrolysis by using the effects model. The optimum experimental condition that gave maximum liquid yield was found to be at a temperature of 500 °C and a gas flow rate of 24 l/min. The catalysts used for catalytic fast pyrolysis were HZSM-5, a commercial catalyst, and red mud, an alumina industry waste material. The liquid products obtained from pennycress were found to have better qualities compared to a typical lignocellulosic feedstocks pyrolysis bio-oil. The bio-oil from the red mud catalyzed experiment had almost neutral pH of 6.5 and the pH in the case of HZSM-5 was 5.7. In comparison to bio-oil from conventional rapid pyrolysis, HZSM-5 and red mud reduced the viscosity of the bio-oil by 3 and 5 times, respectively. However, red mud was only found to be effective in improving the higher heating value (HHV) of the bio-oil from 33.18 MJ/kg (dry basis) in conventional pyrolysis to 35.7 MJ/Kg (dry basis). The HHV of HZSM-5 catalyzed bio-oil was 33.63 MJ/kg. The composition of non-condensable gases and the chemical makeup of the bio-oil from the two catalysts were different, suggesting that the reaction pathways could be different. HZSM-5 had higher selectivity for aromatics whereas red mud produced longer aliphatic chains. The bio-oil obtained from red mud catalytic pyrolysis of field pennycress is a promising alternative energy source that could replace petroleum fuels after some upgrading.

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