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Title: Fatty Amide Determination in Neutral Molecular Fractions of Green Crude Hydrothermal Liquefaction Oils From Algal Biomass

Even though hydrothermal liquefaction (HTL) is a promising route to produce crude oils (referred to as 'green crude'), the molecular composition of the nitrogen fraction of such green crude oils is not fully understood. The goal of this work was to identify and quantify the fraction of fatty amides in green crude oils obtained from five different samples derived from Desmodesmus armatus, Tetraselmis sp., and Chlorella sp. biomass treated under different HTL conditions (260 or 340 degrees C as batch or continuous processes). The goal of this work was to elucidate the nature of the high nitrogen content of the green crude oils. We identified at least 19 distinct fatty amides present in green crude oils and quantified them based on relevant standards in purified fractions after functional group-based separation and enrichment. It was not known how much these compounds contributed to the oils or which molecular fraction they are associated with. We found that fatty amides exclusively partitioned with the neutral fraction of the oils and belonged mainly to one of five categories, based on their functional group substitution, i.e., fatty amides, monomethyl, dimethyl, monoethanolamide, and diethanolamide. The quantification of fatty amides in the neutral oil fraction was basedmore » on respective fatty amide standards, after verification of consistency in response factors between molecules with different substitutions of the amide group. Here, we found that the amount of fatty amides found in each of the five samples varied considerably and ranged between 1.4 and 3.0% of the green crude oils, with the highest levels detected in the sample with the highest oil content, after HTL of biomass derived from a nutrient deprived Chlorella sp. culture.« less
 [1] ;  [2] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Sapphire Energy, San Diego, CA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0887-0624
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Energy and Fuels
Additional Journal Information:
Journal Volume: 31; Journal Issue: 8; Journal ID: ISSN 0887-0624
American Chemical Society (ACS)
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
09 BIOMASS FUELS; hydrothermal liquefaction; HTL; green crude; fatty amides
OSTI Identifier: