Hydrothermal liquefaction of green microalga Kirchneriella sp. under sub- and super-critical water conditions

Kodanda Phani Raj Dandamudi, Tapaswy Muppaneni, Jasmina S. Markovski, Peter Lammers, Shuguang Deng

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Hydrothermal liquefaction (HTL) is one of the promising and reliable thermochemical conversion processes capable of converting wet biomass feedstock into renewable bio-oils. In this study, microalga Kirchneriella sp. was liquefied under hydrothermal conditions in a stainless-steel batch reactor. Various process parameters such as reaction temperature, pressure, biomass solid loading, and reaction duration were varied from 200 to 375 °C, 9–25 MPa, 10–20%, and 15–60 min, respectively. A one-factor-at-a-time approach was employed, and comprehensive experimental runs were further performed at 10% solid loading and a reaction time of 30 min. The maximum bio-crude yield (45.5%) was obtained at 300 °C, 9 MPa, with 10% solid loading and 30 min reaction duration. Fresh algal biomass, bio-oil and biochar samples were characterized by the ultimate and proximate analyses. The bio-oil and bio-char samples obtained at 300 °C, 9 MPa, with 10% solid loading and 30 min reaction duration have a higher heating value of 37.52 and 23.48 MJ kg−1, respectively. The HTL aqueous phase was analyzed for potential co-products by spectrophotometric techniques and is rich in soluble carbohydrates, dissolved ammoniacal nitrogen and phosphates. The metal impurities in the algae, bio-oil, and biochar were identified by ICP-OES where algae and biochar contain a large proportion of phosphorous and magnesium.

Original languageEnglish (US)
Pages (from-to)224-228
Number of pages5
JournalBiomass and Bioenergy
Volume120
DOIs
StatePublished - Jan 1 2019

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Keywords

  • Algae
  • Biocrude oil
  • Elemental analysis
  • Energy

ASJC Scopus subject areas

  • Forestry
  • Renewable Energy, Sustainability and the Environment
  • Agronomy and Crop Science
  • Waste Management and Disposal

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