Energize New Mexico
National Science Foundation
Hydrothermal liquefaction (HTL) is a thermochemical process that uses subcritical water (270-350Â°C and 8-18 MPa) both as a solvent and a reaction medium to convert organic biomass constituents into energy-rich bio-crude oil. HTL is most suitable for conversion of wet feedstocks including algae. In this study, we compare the oil yields and energy recoveries from the HTL of a filamentous algae polyculture grown on freshwater dairy effluent as part of a pilot-scale Algal Turf ScrubberÂ® system at Eastern New Mexico University. Batch HTL conversion experiments were carried out in a 1.8 L autoclave reactor at reaction temperatures and retention times of 310 and 350Â°C, and 30 and 60 minutes, respectively. Algae and reaction conditions were compared based on product yields and the higher heating values (HHV) of the bio-crude oils. The light bio-crude oil (LBO) yield ranged from 11-15 wt. %, heavy bio-crude oil (HBO) yield and char yield were ranged from 5-6 wt. % and 13-20 wt. % respectively. Due to the algae's high ash content, the biomass was pretreated with several organic and inorganic acids to lower ash content prior to HTL to improve bio-crude oil yields. Future work will focus on bio-crude oil and char characterization and applications, and the evaluation of the dairy effluent wastewater treatment and renewable energy production combined process.
Brewer, Catherine. "Pretreatment and Hydrothermal Liquefaction of Filamentous Algae Grown on Dairy Wastewater." (2018). https://digitalrepository.unm.edu/energizenm/685