Hydrothermal liquefaction of sludges/biosolids for the production of bio-crude oils
Conventional wastewater treatment process includes primary treatment (clarifier), secondary treatment (aeration tanks) and anaerobic digestion (AD) of primary sludge (PS) and waste activated sludge (WAS), followed by disposal of the bio-solids from of the AD process. It is estimated that the sludge treatmen/disposal processes account for approximately 40% of the costs for a wastewater treatment plant. Currently three main approaches are: land application, landfill disposal, and incineration/thermal technologies. These approaches are facing great challenges due to various concerns related to the secondary emissions, limited land availability and costs. Compared with the conventional sludge disposal approaches, hydrothermal liquefaction (HTL) technology using hot-pressed water converts sludges/bio-solids into valuable products such as bio-oil, bio-char and aqueous product (AP). The HTL technology is particularly promising for processing high-water-content biomass resources such as sludge and bio-solids as it eliminates the need of costly de watering/drying process that is otherwise required in other thermal/thermo-chemical processes (such as incineration). The long-term objective of this project is to develop low-footprint energy-self-sufficient new sludge treatment processes based on HTL. Trojan is one of the world leading companies providing innovative UV-based solutions to wastewater treatment, drinking water and industrial/residential water purification. Recently, Trojan has decided to heavily invest and expand its commercial interest towards new processes and technologies in the wastewater treatment area. It has a keen interest in evaluating alternative and innovating sludge treatment processes like HTL. The success of the present BiofuelNet-Mitacs internship project could lead to longer-term collaboration between Trojan and the academic researchers to develop new product and new processes on bio-solids disposal and valorization, which would benefit Trojan for development of new products/processes and creation of new jobs.
