Fluid-Bed Catalysis of Lipid-Enhanced Activated Sludge and Its Integration With Wastewater Treatment Facilities

Studies indicated that the lipid content of activated sludges from wastewater treatment facilities could be enhanced by fermentation. The resulting enhanced sludge could contain around 10% (weight) saponifiable lipids or lipids that can be converted to biodiesel. This is a remarkable increase, considering that raw sludges can only yield 2 – 6% (weight) of biodiesel. However, since activated sludge could contain several other compounds (i.e. sterols, waxes, polysaccharides, PHAs, proteins, etc.) in addition to saponifiable lipids, a more efficient process is sought through fluidized bed catalytic cracking. This study describes the in situ production of renewable fuel from lipid-enhanced activated sludge and its integration with existing wastewater treatment facilities.