ABSTRACT
We report the co-liquefaction performance of unicellular, red alga Cyanidioschyzon merolae and Galdieria sulphuraria under sub-critical water conditions within a stainless-steel batch reactor under different temperatures (150-300°C), residence time (15-60min), and Cyanidioschyzon merolae to Galdieria sulphuraria mass loading (0-100%). Individual liquefaction of C. merolae and G. sulphuraria at 300°C achieved maximum biocrude oil yield of 18.9 and 14.0%, respectively. The yield of biocrude oil increased to 25.5%, suggesting a positive synergistic effect during the co-liquefaction of 80-20mass loading of C. merolae to G. sulphuraria. The biocrude oils were analyzed by FT-ICR MS which showed that co-liquefaction did not significantly affect the distribution of product compounds compared to individual oils. The co-liquefied biocrude and biochar have a higher-heating-value of 35.28 and 7.96MJ/kg. Ultimate and proximate analysis were performed on algae biomass, biocrude and biochar.
Subject(s)
Microalgae , Biomass , Oils , Temperature , WaterABSTRACT
This work investigates the hydrothermal liquefaction (HTL) of Cyanidioschyzon merolae algal species under various reaction temperatures and catalysts. Liquefaction of microalgae was performed with 10% solid loading for 30min at temperatures of 180-300°C to study the influences of two base and two acid catalysts on HTL product fractions. Maximum biocrude oil yield of 16.98% was obtained at 300°C with no catalyst. The biocrude oil yield increased to 22.67% when KOH was introduced into the reaction mixture as a catalyst. The algal biocrude and biochar has a higher heating values (HHV) of 32.22MJkg-1 and 20.78MJkg-1 respectively when no catalyst was used. Gas chromatography time of flight mass spectrometry (GC/TOFMS) was employed to analyze the biocrude oil composition, and elemental analysis was performed on the algae, biocrude and biochar samples. Analysis of the HTL aqueous phase revealed the presence of valuable products.
