title: A quantitative kinetic model for the fast and isothermal hydrothermal liquefaction of Nannochloropsis sp.
abstract: Hydrothermal liquefaction (HTL) is a technology for converting algal biomass into biocrude oil and high-value products. To elucidate the underlying kinetics for this process, we conducted isothermal and non-isothermal reactions over a broad range of holding times (10s-60min), temperatures (100-400°C), and average heating rates (110-350°Cmin(-1)). Biocrude reached high yields (⩾37wt%) within 2min for heat-source set-point temperatures of 350°C or higher. We developed a microalgal HTL kinetic model valid from 10s to 60min, including significantly shorter timescales (10s-10min) than any previous model. The model predicts that up to 46wt% biocrude yields are achievable at 400°C and 1min, reaffirming the utility of short holding times and "fast" HTL. We highlight potential trade-offs between maximizing biocrude quantity and facilitating aqueous phase recovery, which may improve biocrude quality.
authors.affiliation: Department of Chemical Engineering, University of Michigan, 2300 Hayward Street, 3074 H.H. Dow Building, Ann Arbor, MI 48109, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Hietala
authors.affiliation: Department of Chemical Engineering, University of Michigan, 2300 Hayward Street, 3074 H.H. Dow Building, Ann Arbor, MI 48109, United States.
authors.forename: Julia L
authors.initials: JL
authors.lastname: Faeth
authors.affiliation: Department of Chemical Engineering, University of Michigan, 2300 Hayward Street, 3074 H.H. Dow Building, Ann Arbor, MI 48109, United States; Department of Chemical Engineering, The Pennsylvania State University, 160 Fenske Lab, University Park, PA 16802, United States. Electronic address: psavage@psu.edu.
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Savage
mesh_terms: D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D006358:Hot Temperature; D007700:Kinetics; D058086:Microalgae / Q000737:chemistry*; D008962:Models, Theoretical; D058009:Stramenopiles / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water
keywords: Hydrothermal liquefaction; Kinetic model; Microalgae; Temperature profile