Production of mid-distillation fuels from syngas using cobalt nanocatalyst supported on Gracilaria gracilis macroalgae biochar

This study investigates the application of biochar from the macroalgae pyrolysis of Gracylaria gracilis as catalyst support for the production of mid-distillation fuels. Macroalgae were pyrolyzed at 550 °C, and the resulting products were evaluated. The major product of the pyrolysis was biochar (40.1%). The gaseous product mostly contained carbon dioxide (51.9%) and hydrogen (26.3%), and the liquid product mainly contained oxygenate and nitrogenate compounds. The abtained biochar was activated and impregnated with 15% cobalt and then used as a catalyst in the Fisher-Tropesh process under conditions of syngas flow of 45 ml/min (H2/CO = 2), 18 bar pressure and temperature of 220 °C. The results showed that carbon monoxide conversion was 64.2%, and the highest product selectivity was for heavy hydrocarbons (74%), while the selectivity of carbon dioxide as a by-product was 2.3%. Catalyst characterization was performed by BET, XRD, TPR, TGA and TEM methods.