Process development for hydrothermal liquefaction of algae feedstocks in a continuous-flow reactor
Algal Research 2 (2013) 445–454
Contents lists available at ScienceDirect
Algal Research journal homepage: www.elsevier.com/locate/algal
Process development for hydrothermal liquefaction of algae feedstocks in a continuous-flow reactor
Douglas C. Elliott ⁎, Todd R. Hart, Andrew J. Schmidt, Gary G. Neuenschwander, Leslie J. Rotness,
Mariefel V. Olarte, Alan H. Zacher, Karl O. Albrecht, Richard T. Hallen, Johnathan E. Holladay
Pacific Northwest National Laboratory, P.O. Box 999, MSIN P8-60, Richland, WA 99352, United States
a r t i c l e
i n f o
Article history:
Received 6 June 2013
Received in revised form 26 August 2013
Accepted 29 August 2013
Available online 29 September 2013
Keywords:
Hydrothermal
Liquefaction
Catalyst
Hydrotreating
Gasification
Aqueous phase
a b s t r a c t
Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL).
High levels of carbon conversion to gravity separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment
(20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt.% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic
Contents lists available at ScienceDirect
Algal Research journal homepage: www.elsevier.com/locate/algal
Process development for hydrothermal liquefaction of algae feedstocks in a continuous-flow reactor
Douglas C. Elliott ⁎, Todd R. Hart, Andrew J. Schmidt, Gary G. Neuenschwander, Leslie J. Rotness,
Mariefel V. Olarte, Alan H. Zacher, Karl O. Albrecht, Richard T. Hallen, Johnathan E. Holladay
Pacific Northwest National Laboratory, P.O. Box 999, MSIN P8-60, Richland, WA 99352, United States
a r t i c l e
i n f o
Article history:
Received 6 June 2013
Received in revised form 26 August 2013
Accepted 29 August 2013
Available online 29 September 2013
Keywords:
Hydrothermal
Liquefaction
Catalyst
Hydrotreating
Gasification
Aqueous phase
a b s t r a c t
Wet algae slurries can be converted into an upgradeable biocrude by hydrothermal liquefaction (HTL).
High levels of carbon conversion to gravity separable biocrude product were accomplished at relatively low temperature (350 °C) in a continuous-flow, pressurized (sub-critical liquid water) environment
(20 MPa). As opposed to earlier work in batch reactors reported by others, direct oil recovery was achieved without the use of a solvent and biomass trace components were removed by processing steps so that they did not cause process difficulties. High conversions were obtained even with high slurry concentrations of up to 35 wt.% of dry solids. Catalytic hydrotreating was effectively applied for hydrodeoxygenation, hydrodenitrogenation, and hydrodesulfurization of the biocrude to form liquid hydrocarbon fuel. Catalytic hydrothermal gasification was effectively applied for HTL byproduct water cleanup and fuel gas production from water soluble organics, allowing the water to be considered for recycle of nutrients to the algae growth ponds. As a result, high conversion of algae to liquid hydrocarbon and gas products was found with low levels of organic
References: Wiley & Sons, Ltd., Chichester, UK, 2011, pp. 200–231. [2] M.C. Chow, W.R. Jackson, A.L. Chaffee, M. Marshall, Thermal treatment of algae for production of biofuel, Energy Fuel 27 (2013) 1926–1950. feedstocks, Ind. Eng. Chem. Res. 51 (2012) 10768–10777. from microalgae and CO2 mitigation, J. Appl. Phycol 21 (2009) 529–541. [5] NABC HTL highlights, (last accessed May 2, 2013). http://www.nabcprojects.org/ pdfs/htl_stage_2_developments_102212.pdf http://www.nabcprojects.org/pdfs/ biorefinery residues: final CRADA Report #PNNL/277, PNNL-19453, Pacific Northwest National Laboratory, Richland, Washington, 2010. [7] R.S. Sayre, Bioscience 60 (2010) 722–727. [8] D.L. Barreiro, W. Prins, F. Ronsse, W. Brilman, Hydrothermal liquefaction (HTL) of microalgae for biofuel production: state of the art review and future prospects, Biomass Bioenergy 53 (2013) 113–127. [9] S.S. Toor, L. Rosendahl, A. Rudolf, Hydrothermal liquefaction of biomass: a review of subcritical water technologies, Energy 36 (2011) 2328–2342. (1994) 1855–1857. [11] T. Minowa, S.-Y. Yokoyama, M. Kishimoto, T. Okakura, Oil production from algal cells of Dunaliella tertiolecta by direct thermochemical liquefaction, Fuel 74 (1995) 1735–1738. [12] (a) A.B. Ross, P. Biller, M.L. Kubacki, H. Li, A. Lea-Langton, J.M. Jones, Hydrothermal processing of microalgae using alkali and organic acids, Fuel 89 (2010) 2234–2243; Technol. 102 (2011) 215–225; (c) P Environ. Sci. 3 (2010) 1073–1078. process as conversion method in an algae biorefinery concept, Energy Fuel 26 (2012) 642–657; HTT mechanism elucidation, Energy Fuel 26 (2012) 658–671. 102 (2011) 6221–6229; (b) U of algal biomass, Bioresour. Technol. 102 (2011) 3380–3387; (c) U pyrolysis for bio-oil production from microalgae, Energy Fuel 25 (2011) 5472–5482. (b) P. Duan, P.E. Savage, Hydrothermal liquefaction of a microalga with heterogeneous catalysts, Ind. Eng. Chem. Res. 50 (2011) 52–61; (c) P.J the product, Biomass Bioenergy 46 (2012) 317–331. May 2, 2013). Laboratory, Richland, Washington, 2009.