Hydrothermal upgrading of algae paste: inorganics and recycling potential in the aqueous phase
File(s)
Author(s)
Patel, B
Guo, M
Chong, C
Sarudin, SHM
Hellgardt, K
Type
Journal Article
Abstract
Hydrothermal Liquefaction (HTL) for algal biomass conversion is a promising technology capable of producing high yields of biocrude as well as partitioning even higher quantity of nutrients in the aqueous phase. To assess the feasibility of utilizing the aqueous phase, HTL of Nannochloropsis sp. was carried out in the temperature range of 275 to 350 °C and Residence Times (RT) ranging between 5 and 60 min The effect of reaction conditions on the NO3− , PO43 − , SO42 − , Cl− , Na+ , and K+ ions as well as Chemical Oxygen Demand (COD) and pH was investigated with view of recycling the aqueous phase for either cultivation or energy generation via Anaerobic Digestion (AD), quantified via Lifecycle Assessment (LCA). It addition to substantial nutrient partitioning at short RT, an increase in alkalinity to almost pH 10 and decrease in COD at longer RT was observed. The LCA investigation found reaction conditions of 275 °C/30 min and 350 °C/10 min to be most suitable for nutrient and energy recovery but both processing routes offer environmental benefit at all reaction conditions, however recycling for cultivation has marginally better environmental credentials compared to AD.
Date Issued
2016-06-16
Date Acceptance
2016-06-07
Citation
Science of the Total Environment, 2016, 568, pp.489-497
ISSN
0048-9697
Publisher
Elsevier
Start Page
489
End Page
497
Journal / Book Title
Science of the Total Environment
Volume
568
Copyright Statement
© 2016 Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
2017-06-16
Subjects
Anaerobic Digestion (AD)
Biocrude
Hydrothermal Liquefaction (HTL)
Life Cycle Assessment (LCA)
Microalgae
Nutrient recycling
Environmental Sciences
MD Multidisciplinary
Publication Status
Published