Applied Microbiology and Biotechnology

, Volume 103, Issue 2, pp 673–684 | Cite as

Hydrothermal liquefaction of organic resources in biotechnology: how does it work and what can be achieved?

  • Judit SandquistEmail author
  • Roman Tschentscher
  • Gonzalo del Alamo Serrano


Increasing the overall carbon and energy efficiency by integration of thermal processes with biological ones has gained considerable attention lately, especially within biorefining. A technology that is capable of processing wet feedstock with good energy efficiency is advantageous. Such a technology, exploiting the special properties of hot compressed water is called hydrothermal liquefaction. The reaction traditionally considered to take place at moderate temperatures (200–350 °C) and high pressures (10–25 MPa) although recent findings show the benefits of increased pressure at higher temperature regions. Hydrothermal liquefaction is quite robust, and in theory, all wet feedstock, including residues and waste streams, can be processed. The main product is a so-called bio-crude or bio-oil, which is then further upgraded to fuels or chemicals. Hydrothermal liquefaction is currently at pilot/demo stage with several lab reactors and a few pilots already available as well as there are a few demonstration plants under construction. The applied conditions are quite severe for the processing equipment and materials, and several challenges remain before the technology is commercial. In this review, a description is given about the influence of the feedstock, relevant for integration with biological processing, as well as the processing conditions on the hydrothermal process and products composition. In addition, the relevant upgrading methods are presented.


Hydrothermal liquefaction Biomass Biofuels Bio-oil upgrading 


Funding information

This work was supported by the Research Council of Norway’s scheme for Centres for Environment-friendly Energy Research (FME) under the FME Bio4Fuels (project number 257622, duration 2016–2024).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.


  1. Akhtar J, Amin NAS (2011) A review on process conditions for optimum bio-oil yield in hydrothermal liquefaction of biomass. Renew Sust Energy Rev 15:1615–1624. Google Scholar
  2. Akiya N, Savage PE (2002) Roles of water for chemical reactions in high-temperature water. Chem Rev 102(8):2725–2750. Google Scholar
  3. Anastasakis K, Ross AB (2011) Hydrothermal liquefaction of the brown macro-alga Laminaria Saccharina: effect of reaction conditions on product distribution and composition. Bioresour Technol 102(7):4876–4883. Google Scholar
  4. Barbier J, Charon N, Dupassieux N, Loppinet-Serani A, Mahé L, Ponthus J, Courtiade M, Ducrozet A, Quoineaud AA, Cansell F (2012) Hydrothermal conversion of lignin compounds. A detailed study of fragmentation and condensation reaction pathways. Biomass Bioenergy 46:479–491. Google Scholar
  5. Barreiro LD, Prins W, Ronsse F, Brilman W (2013) Hydrothermal liquefaction (HTL) of microalgae for biofuel production: state of the art review and future prospects. Biomass Bioenergy 53:113–127. Google Scholar
  6. Belkheiri T, Andersson SI, Mattsson C, Olausson L, Theliander H, Vamling L (2018) Hydrothermal liquefaction of Kraft lignin in subcritical water: influence of phenol as capping agent. Energy Fuel 32(5):5923–5932. Google Scholar
  7. Bhaskar T, Sera A, Muto A, Sakata Y (2008) Hydrothermal upgrading of wood biomass: influence of the addition of K2CO3 and cellulose/lignin ratio. Fuel 87:2236–2242. Google Scholar
  8. Biller P, Ross AB (2011) Potential yields and properties of oil from the hydrothermal liquefaction of microalgae with different biochemical content. Bioresour Technol 102(1):215–225. Google Scholar
  9. Biller P, Sharma BK, Kunwar B, Ross AB (2015) Hydroprocessing of bio-crude from continuous hydrothermal liquefaction of microalgae. Fuel 159:197–205. Google Scholar
  10. Biller P, Madsen RB, Klemmer M, Becker J, Iversen BB, Glasius M (2016) Effect of hydrothermal liquefaction aqueous phase recycling on bio-crude yields and composition. Bioresour Technol 220:190–199. Google Scholar
  11. Bo Z, Hua-Jiang H, Shri R (2008) Reaction Kinetics of the Hydrothermal Treatment of Lignin. Applied Biochemistry and Biotechnology 147 (1-3):119–131.
  12. Boocock DGB, Sherman KM (1985) Further aspects of powdered poplar wood liquefaction by aqueous pyrolysis. Can J Chem Eng 63:627–633. Google Scholar
  13. Brand S, Susanti RF, Kim SK, Lee HS, Kim J, Sang BI (2013) Supercritical ethanol as an enhanced medium for lignocellulosic biomass liquefaction: influence of physical process parameters. Energy 59:173–182. Google Scholar
  14. Bühler W, Dinjus E, Ederer HJ, Kruse A, Mas C (2002) Ionic reactions and pyrolysis of glycerol as competing reaction pathways in near- and supercritical water. J Supercrit Fluids 22(1):37–53. Google Scholar
  15. Caglar A, Demirbas A (2001) Conversion of cotton cocoon shell to liquid products by supercritical fluid extraction and low-pressure pyrolysis in the presence of alkalis. Energy Convers Manag 42(9):1095–1104. Google Scholar
  16. Chen K, Hao S, Lyu H, Luo G, Zhang S, Chen J (2017) Ion exchange separation for recovery of monosaccharides, organic acids and phenolic compounds from hydrolysates of lignocellulosic biomass. Sep Purif Technol 172:100–106. Google Scholar
  17. Dãrãban IM, Rosendahl LA, Pedersen TH, Iversen SM (2015) Pretreatment methods to obtain pumpable high solid loading wood–water slurries for continuous hydrothermal liquefaction systems. Biomass Bioenergy 81:437–443. Google Scholar
  18. Demirbas A (2006) Thermochemical conversion of biomass to liquid products in the aqueous medium. Energy Sources 27:1235–1243. Google Scholar
  19. Doassans-Carrère N, Ferrasse JH, Boutin O, Mauviel G, Lédé J (2014) Comparative study of biomass fast pyrolysis and direct liquefaction for bio-oils production: products and characterizations. Energy Fuel 28(8):5103–5111. Google Scholar
  20. Dutta RP, McCaffrey WC, Gray MR, Muehlenbachs K (2000) Thermal cracking of Athabasca bitumen: influence of steam on reaction chemistry. Energy Fuel 14(3):671–676. Google Scholar
  21. Eboibi BE, Lewis DM, Ashman PJ, Chinnasamy S (2015) Integrating anaerobic digestion and hydrothermal liquefaction for renewable energy production: an experimental investigation. Environ Prog Sustain Energy 34(6):1662–1673. Google Scholar
  22. Eckert CA, Chandler K (1998) Tuning fluid solvents for chemical reactions. J Supercrit Fluids 13:187–195Google Scholar
  23. Elliot DC, Sealock LJ, Baker EG (1994a) Chemical processing in high-pressure aqueous environments. 3. Batch reactor process development experiments for organics destruction. Ind Eng Chem Res 33(3):558–565. Google Scholar
  24. Elliot DC, Phelps MR, Sealock LJ, Baker EG (1994b) Chemical processing in high pressure aqueous environments. 4. Continuous-flow reactor process development experiments for organics destruction. Ind Eng Chem Res 33(3):566–574. Google Scholar
  25. Elliott DC, Hart TR, Schmidt AJ, Neuenschwander GG, Rotness LJ, Olarte MV, Zacher AH, Albrecht KO, Hallen RT, Holladay JE (2013) Process development for hydrothermal liquefaction of algae feedstocks in a continuous-flow reactor. Algal Res 2(4):445–545. Google Scholar
  26. Elliott DC, Biller P, Ross AB, Schmidt AJ, Jones SB (2015) Hydrothermal liquefaction of biomass: developments from batch to continuous process. Bioresour Technol 178:147–156. Google Scholar
  27. Faeth JL, Valdez PJ, Savage PE (2013) Fast hydrothermal liquefaction of Nannochloropsis sp. to produce biocrude. Energy Fuel 27(3):1391–1398.
  28. Fang Z, Sato T, Smith RL Jr, Inomata H, Arai K, Kozinski JA (2008) Reaction chemistry and phase behavior of lignin in high-temperature and supercritical water. Bioresour Technol 99:3424–3430. Google Scholar
  29. Forchheim D, Hornung U, Kruse A, Sutter T (2014) Kinetic modelling of hydrothermal lignin depolymerisation. Waste Biomass Valoriz 5:985–994. Google Scholar
  30. Gollakota ARK, Kishore N, Gu S (2018) A review on hydrothermal liquefaction of biomass. Renew Sust Energ Rev 81(1):1378–1392. Google Scholar
  31. Gullón B, Yáñez R, Alonso JL, Parajó JC (2010) Production of oligosaccharides and sugars from rye straw: a kinetic approach. Bioresour Technol 101(17):6676–6684. Google Scholar
  32. He BJ, Zhang Y, Funk TL, Riskowski GL, Yin Y (2000) Thermochemical conversion of swine manure: an alternative process for waste treatment and renewable energy production. Transactions of the ASAE 43(6):1827–1833. Google Scholar
  33. Hietala DC, Faeth JL, Savage PE (2016) A quantitative kinetic model for the fast and isothermal hydrothermal liquefaction of Nannochloropsis sp. Bioresour Technol 214:102–111.
  34. Hodes M, Marrone PA, Hong GT, Smith KA, Tester JW (2004) Salt precipitation and scale control in supercritical water oxidation—part a: fundamentals and research. J Supercrit Fluids 29:265–288. Google Scholar
  35. Hoffmann J, Jensen CU, Rosendahl LA (2016) Co-processing potential of HTL bio-crude at petroleum refineries—part 1: fractional distillation and characterization. Fuel 165:526–535. Google Scholar
  36. Hu J, Shen D, Wu S, Zhang H, Xiao R (2014) Effect of temperature on structure evolution in char from hydrothermal degradation of lignin. J Anal Appl Pyrolysis 106:118–124. Google Scholar
  37. Hu Y, Feng S, Yuan Z, Xu C, Bassi A (2017) Investigation of aqueous phase recycling for improving bio-crude oil yield in hydrothermal liquefaction of algae. Bioresour Technol 239:151–159. Google Scholar
  38. Huang H, Yuan X, Zhu H, Li H, Liu Y, Wang X, Zeng G (2013) Comparative studies of thermochemical liquefaction characteristics of microalgae, lignocellulosic biomass and sewage sludge. Energy 56:52–60. Google Scholar
  39. Hunter SE, Savage PE (2004) Recent advances in acid-and base-catalyzed organic synthesis in high-temperature liquid water. Chem Eng Sci 59:4903–4909. Google Scholar
  40. Isa KM, Snape CE, Uguna C, Meredith W (2015) High conversions of miscanthus using sub- and supercritical water above 400°C. J Anal Appl Pyrolysis 113:646–654. Google Scholar
  41. Jansen JPD, Marx S, Venter R, Barnard A (2016) The effect of particle size on the quality and yield of batch and continuous hydrothermal liquefaction products. International Conference on Advances in Science, Engineering, Technology and Natural Resources (ICASETNR-16) Nov. 24–25, 2016 Parys (South Africa)
  42. Jazrawi C, Biller P, Ross AB, Montoya A, Maschmeyer T, Haynes BS (2013) Pilot plant testing of continuous hydrothermal liquefaction of microalgae. Algal Res 2(3):268–277. Google Scholar
  43. Jensen CU, Hoffmann J, Rosendahl LA (2016) Co-processing potential of HTL bio-crude at petroleum refineries—part 2: a parametric hydrotreating study. Fuel 165:536–543. Google Scholar
  44. Jensen CU, Rodriguez Guerrero JK, Karatzos S, Olofsson G, Iversen SB (2017) Fundamentals of Hydrofaction™: renewable crude oil from woody biomass. Biomass Conv Bioref 7:495–509. Google Scholar
  45. Kabyemela BM, Takigawa M, Adschiri T, Malauan RM, Arai K (1998) Mechanism and kinetics of cellulose decomposition in sub and supercritical water. Ind Eng Chem Res 37(2):357–361. Google Scholar
  46. Karagöz S, Bhaskar T, Muto A, Sakata Y, Uddin A (2004) Low-temperature hydrothermal treatment of biomass: effect of reaction parameters on products and boiling point distributions. Energy Fuel 18(1):234–241. Google Scholar
  47. Karagöz S, Bhaskar T, Muto A, Sakata Y (2005) Comparative studies of oil compositions produced from sawdust, rice husk, lignin and cellulose by hydrothermal treatment. Fuel 84:875–884. Google Scholar
  48. Karagöz S, Bhaskar T, Muto A, Sakata Y (2006) Hydrothermal upgrading of biomass: effect of K2CO3 concentration and biomass/water ratio on products distribution. Bioresour Technol 97(1):90–98. Google Scholar
  49. Kim KH, Brown RC, Kieffer M, Bai X (2014) Hydrogen-donor-assisted solvent liquefaction of lignin to short-chain alkylphenols using a micro reactor/gas chromatography system. Energy Fuel 28(10):6429–6437.
  50. Kruse A, Dinjus E (2007) Hot compressed water as reaction medium and reactant 2. Degradation reactions. J Supercrit Fluids 41:361–379. Google Scholar
  51. Kruse A, Gawlik A (2003) Biomass conversion in water at 330-410 °C and 30-50 MPa. Identification of key compounds for indicating different chemical reaction pathways. Ind Eng Chem Res 42(2):267–279. Google Scholar
  52. Kücük MM, Agirtas S (1999) Liquefaction of Prangmites australis by supercritical gas extraction. Bioresour Technol 69:141–143. Google Scholar
  53. Lange JP (2017) Don’t forget product recovery in catalysis research—check the distillation resistance. ChemSusChem 10:245–252. Google Scholar
  54. Li R, Xie Y, Yang T, Li B, Wang W, Kai X (2015) Effects of chemical-biological pretreatment of corn stalks on the bio-oils produced by hydrothermal liquefaction. Energy Convers Manag 93:23–30. Google Scholar
  55. Li Q, Liu D, Song L, Wu P, Yan Z, Li M (2016) Investigation of solvent effect on the hydro-liquefaction of sawdust: an innovative reference approach using tetralin as chemical probe. Fuel 164:94–98. Google Scholar
  56. Li Q, Liu D, Song L, Hou X, Wu C, Yan Z (2018) Efficient hydro-liquefaction of woody biomass over ionic liquid nickel based catalyst. Ind Crop Prod 113:157–166. Google Scholar
  57. Licella webpage, Accessed 29 Aug 2018
  58. Liu HM, Xie XA, Li MF, Sun RS (2012) Hydrothermal liquefaction of cypress: effects of reaction conditions on 5-lump distribution and composition. J Anal Appl Pyrolysis 94(6):177–183. Google Scholar
  59. Lyckeskog HN, Mattsson C, Olausson L, Andersson SI, Vamling L, Theliander H (2017) Thermal stability of low and high Mw fractions of bio-oil derived from lignin conversion in subcritical water. Biomass Conv Bioref 7:401–414. Google Scholar
  60. Matsui T, Koike Y (2010) Methane fermentation of a mixture of seaweed and milk at a pilot-scale plant. J Biosci Bioeng 110:558–563. Google Scholar
  61. Mattsson C, Andersson SI, Belkheiri T, Åmand LE, Olausson L, Vamling L, Theliander H (2016) Using 2D NMR to characterize the structure of the low and high molecular weight fractions of bio-oil obtained from LignoBoost™ kraft lignin depolymerized in subcritical water. Biomass Bioenergy 95:364–377. Google Scholar
  62. Mehmood A, Watson I (2015) Hydrothermal liquefaction and aqueous phase reforming of algal biomass. In: 5th UK algae Conference, Glasgow, UK, 10 Jul 2015Google Scholar
  63. Minowa T, Ogi T (1998) Hydrogen production from cellulose using a reduced nickel catalyst. Catal Today 45:411–416. Google Scholar
  64. Minowa T, Murakami M, Dote Y, Ogi T, Yokoyama S (1995) Oil production from garbage by thermochemical liquefaction. Biomass Bioenergy 8:117–120. Google Scholar
  65. Okuda K, Ohara S, Umetsu M, Takami S, Adschiri T (2008) Disassembly of lignin and chemical recovery in supercritical water and p-cresol mixture. Studies on lignin model compounds. Bioresour Technol 99(6):1846–1852. Google Scholar
  66. Orebom A, Verendel J, Samec JSM (2018) High yields of bio oils from hydrothermal processing of thin black liquor without the use of catalysts or capping agents. ACS Omega 3(6):6757–6763. Google Scholar
  67. Pedersen TH, Rosendahl LA (2015) Production of fuel range oxygenates by supercritical hydrothermal liquefaction of lignocellulosic model systems. Biomass Bioenergy 83:206–215. Google Scholar
  68. Pedersen TH, Jasiūnas L, Casamassima L, Singh S, Jensen T, Rosendahl LA (2015) Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood. Energy Convers Manag 106:886–891. Google Scholar
  69. Pedersen TH, Jensen CU, Sandström L, Rosendahl LA (2017) Full characterization of compounds obtained from fractional distillation and upgrading of a HTL biocrude. Appl Energy 202:408–419. Google Scholar
  70. Pienkos PT, Zhang M (2009) Role of pretreatment and conditioning processes on toxicity of lignocellulosic biomass hydrolysates. Cellulose 16(4):743–762. Google Scholar
  71. Posmanik R, Labatut AR, Kim AH, Usack JG, Tester JW, Angenent L (2017) Coupling hydrothermal liquefaction and anaerobic digestion for energy valorization from model biomass feedstocks. Bioresour Technol 233:134–143. Google Scholar
  72. Ramos-Tercero E, Bertucco A, Brilman W (2015) Process water recycle in hydrothermal liquefaction of microalgae to enhance bio-oil yield. Energy Fuel 29(4):2422–2430.
  73. Rogalinski T, Herrmann S, Brunner G (2005) Production of amino acids from bovine serum albumin by continuous sub-critical water hydrolysis. J Supercrit Fluids 36(1):49–58. Google Scholar
  74. Sakaki T, Shibata M, Miki T, Hirosue H, Hayashi N (1996) Reaction model of cellulose decomposition in near-critical water and fermentation of products. Bioresour Technol 58:197–202. Google Scholar
  75. Sato T, Osada M, Watanabe M, Shirai M, Arai K (2003) Gasification of alkylphenols with supported noble metal catalysts in supercritical water. Ind Eng Chem Res 42:4277–4282. Google Scholar
  76. Servaes K, Vandezande P, Vendamme R, Vanbroekhoven K, Buekenhoudt A, Diels L (2018) Lignin derived fractions—developing performance based chemicals and materials using membrane separation technology. Proceedings of ECO-BIO 2018, Dublin/Ireland, March 2018Google Scholar
  77. Shuping Z, Yulong W, Mingde Y, Kaleem I, Chun L, Tong J (2010) Production and characterization of bio-oil from hydrothermal liquefaction of microalgae Dunaliella tertiolecta cake. Energy 35(12):5406–5411.
  78. Song C, Hu H, Zhu S, Wang G, Chen G (2004) Nonisothermal catalytic liquefaction of corn stalk in subcritical and supercritical water. Energy Fuel 18(1):90–96. Google Scholar
  79. Steeper Energy webpage Accessed 29 Aug 2018
  80. Stefanidis SD, Kalogiannis KG, Lappas AA (2018) Co-processing bio-oil in the refinery for drop-in biofuels via fluid catalytic cracking. WIREs Energy Environ 7(3):281. Google Scholar
  81. Sudasinghe N, Cort JR, Hallen RT, Olarte MV, Schmidt A, Schaub T (2014) Hydrothermal liquefaction oil and hydrotreated product from pine feedstock characterized by heteronuclear two-dimensional NMR spectroscopy and FT-ICR mass spectrometry. Fuel 137:60–69. Google Scholar
  82. Sugano M, Takagi H, Hirano K, Mashimo K (2008) Hydrothermal liquefaction of plantation biomass with two kinds of wastewater from paper industry. J Mater Sci 43:2476–2486. Google Scholar
  83. Tanneru SK, Steele PH (2015) Direct hydrocracking of oxidized bio-oil to hydrocarbons. Fuel 154:268–274. Google Scholar
  84. Theegala CS, Midgett JS (2012) Hydrothermal liquefaction of separated dairy manure for production of bio-oils with simultaneous waste treatment. Bioresour Technol 107:456–463. Google Scholar
  85. Toledano A, Serrano L, Labidi J (2014) Improving base catalyzed lignin depolymerization by avoiding lignin repolymerization. Fuel 116:617–624. Google Scholar
  86. Toor SS, Rosendahl L, Rudolf A (2011) Hydrothermal liquefaction of biomass: a review of subcritical water technologies. Energy 36:2328–2342. Google Scholar
  87. Unsal M, Livatyali H, Aksoy P, Serhat Gul S, Onoglu A (2015) CatLiq- catalytic hydrothermal liquefaction process from pilot scale to demo scale. J Fundam Renewable Energy Appl 5:5. Google Scholar
  88. Wang G, Li W, Li B, Chen H (2007) Direct liquefaction of sawdust under syngas. Fuel 86(10–11):1587–1593. Google Scholar
  89. Wang Y, Wang H, Lin H, ZhengY ZJ, Pelletier A, Li K (2013) Effects of solvents and catalysts in liquefaction of pinewood sawdust for the production of bio-oils. Biomass Bioenergy 59:158–167. Google Scholar
  90. Wasserman E, Wood B, Brodhol J (1995) The static dielectric constant of water at pressures up to 20 kbar and temperatures to 1273 K: experiment, simulations, and empirical equations. Geochim Cosmochim Acta 59(1):1–6. Google Scholar
  91. Watanabe M, Iida T, Inomata H (2006) Decomposition of a long chain saturated fatty acid with some additives in hot compressed water. Energy Convers Manag 47:3344–3350. Google Scholar
  92. Watson J, Si B, Li H, Liu Z, Zhang Y (2017) Influence of catalysts on hydrogen production from wastewater generated from the HTL of human feces via catalytic hydrothermal gasification. Int J Hydrog Energy 42(32):20503–20511. Google Scholar
  93. Wirth B, Mumme J (2013) Anaerobic digestion of waste water from hydrothermal carbonization of corn silage. Appl Bioenergy 1:1–10. Google Scholar
  94. Wolfson A, Dlugy C, Shotland Y, Tavor D (2009) Glycerol as solvent and hydrogen donor in transfer hydrogenation–dehydrogenation reactions. Tetrahedron Lett 50(43):5951–5953. Google Scholar
  95. Xiu S, Shahbazi A, Shirley V, Cheng D (2010) Hydrothermal pyrolysis of swine manure to bio-oil: effects of operating parameters on products yield and characterization of bio-oil. J Anal Appl Pyrolysis 88:73–79. Google Scholar
  96. Xu C, Etcheverry T (2008) Hydro-liquefaction of woody biomass in sub and supercritical ethanol with iron-based catalysts. Fuel 87(3):335–345.
  97. Yan Y, Xu J, Li T, Ren Z (1999) Liquefaction of sawdust for liquid fuel. Fuel Process Technol 60(2):135–143. Google Scholar
  98. Yin S, Dolan R, Harris M, Tan Z (2010) Subcritical hydrothermal liquefaction of cattle manure to bio-oil: effect of conversion parameters on bio-oil yield and characterization of bio-oil. Bioresour Technol 101(10):3657–3664. Google Scholar
  99. Yu Y, Lou X, Wu H (2008) Some recent advances in hydrolysis of biomass in hot compressed water and its comparisons with other hydrolysis methods. Energy Fuel 22(1):46–60. Google Scholar
  100. Yu J, Biller P, Mamahkel A, Klemmer M, Becker J, Glasius M, Iversen BB (2017) Catalytic hydrotreatment of bio-crude produced from the hydrothermal liquefaction of aspen wood: a catalyst screening and parameter optimization study. Sustainable Energy Fuels 1:832–841. Google Scholar
  101. Zhang B, Keitz MV, Valentas K (2009) Thermochemical liquefaction of high-diversity grassland perennials. J Anal Appl Pyrolysis 84(1):18–24. Google Scholar
  102. Zhong C, Wei X (2004) A comparative experimental study on the liquefaction of wood. Energy 29:1731–1741. Google Scholar
  103. Zhou D, Zhang L, Zhang S, Fu H, Chen J (2010) Hydrothermal liquefaction of macroalgae Enteromorpha prolifera to bio-oil. Energy Fuel 24(7):4054–4061. Google Scholar
  104. Zhou Z, Zhang W, Sun D, Zhu L, Jiang J (2016) Renewable biofuel production from hydrocracking of soybean biodiesel with a commercial petroleum Ni-W catalyst. Int J Green Energy 13(12):1185–1192. Google Scholar
  105. Zhu Z, Rosendahl L, Toor SS, Yu D, Chen G (2015) Hydrothermal liquefaction of barley straw to bio-crude oil: effects of reaction temperature and aqueous phase recirculation. Appl Energy 137:183–192. Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.SINTEF Energy ResearchTrondheimNorway
  2. 2.SINTEF IndustryTrondheimNorway

Personalised recommendations