DEMETALLATION OF ALGAL BIOCRUDE OIL PRODUCED VIA HYDROTHERMAL LIQUEFACTION

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Author:
Pany, Andrew Sylvester
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Phillip Savage, Thesis Supervisor
  • Themis Matsoukas, Honors Advisor
Keywords:
  • Chemical Engineering
  • Algae
  • Renewables
Abstract:
We investigated the effects of temperature (350-450 C), holding time (10-60 min), water loading (30-95% by volume), and biomass loading (5-15% by weight) on bio-oil yield and metal distribution in the bio-oil from hydrothermal liquefaction (HTL) of Nannochloropsis sp. Liquefaction produced a biocrude, along with gaseous, aqueous, and solid by-product fractions. The yields of biocrude depend greatly on both reaction time and temperature, with the maximum yield, 35.361.50%, occurring at 350C and 60 minutes. Further, the highest yield with respect to water loading by volume was at 60% (35.272.12%) while the highest yield with respect to biomass loading by weight occurred at both 10% and 15% (32.131.72). All obtained biocrude phases were analyzed via ICP-OES to determine the effects of changing the HTL process variables on the concentrations of metals, namely iron and sodium. Iron exhibited the lowest concentrations at reaction conditions of 450 C and 30 minutes (608.32 ppm), water loading of 30% by volume (99169 ppm), and biomass loading of 10% by weight (1463.544.47 ppm). Sodium exhibited the lowest concentrations at reaction conditions of 350C and 60 minutes (103120 ppm), water loading of 95% by volume (569296 ppm), and biomass loading of 15% (56926 ppm). The data for iron concentrations was much more consistent than that of sodium. The quantitative results reported herein provide the basis for determining the distribution of deleterious metals in bio-oil.