Bio-oil upgrading through biodiesel emulsification and catalytic vapour cracking

• Main Author: Yu, Joyleene Ruth
• Language: English
• Published: University of British Columbia 2014
• Online Access: http://hdl.handle.net/2429/46841

With our limited fuel supplies struggling to keep up with our ever-increasing demand for energy, and the rising trend towards sustainable and cleaner technologies, the need to harness the potential of bio-oil as an alternative source of energy has never been more compelling. Although crude bio-oil can already be utilized to supplement heating oils and boiler fuels, its greater value lies in its potential as a source of transportation fuels and chemicals after upgrading. In collaboration with Diacarbon Energy Inc., the main objectives of this project were twofold: (1) investigating the effect of extraction location from their proprietary pyrolysis unit on crude bio-oil quality prior to its emulsification with biodiesel, and characterizing the resulting biodiesel- and lignin-rich layers; and (2) designing and building a catalytic test unit to perform in situ cracking of slow pyrolysis vapours. Experimental results confirmed that extraction location does affect the crude bio-oil quality. The effect of the surfactant on the emulsification was minimal as the resulting biodiesel-rich layer from the emulsification without the surfactant showed similar improvements in terms of water content, viscosity, TAN and HHV. A water mass balance confirmed that the majority of the water (~97%) is retained in the lignin-rich phase after emulsification. This is significant because the solvency of biodiesel can be utilized to upgrade bio-oils by selectively extracting its desirable fuel components into a biodiesel-rich phase, which can then be easily separated from the lignin- rich phase where the higher molecular weight compounds, such as pyrolytic lignin, as well as the majority of the water, are retained. The bio-oil samples obtained from the non-catalytic and catalytic vapour cracking experiments separated into two distinct layers – an aqueous and organic layer. While the aqueous layers were fairly similar in nature, the organic layer from the catalytic experiment showed a significant decrease in viscosity (94.3% less) and water content (64.3% less). The organic layer from the catalytic pyrolysis remained homogeneous while that from the non-catalytic pyrolysis split into a hazy aqueous layer (with suspended oil droplets) sandwiched between a thin organic layer on top and a thicker organic layer at the bottom.