CHARACTERISTICS STUDIES OF BIO-OIL PRODUCED VIA FIXED-BED CATALYTIC PYROLYSIS OF THE MARINE MICRO ALGAE TETRASELMIS SUECICA

摘要

The use of microalgae as a renewable feedstock for the production of fuels and chemicals has environmental benefits such as curtailing CO_2 emissions and reducing reliance on fossil fuels. Thermochemical processing of microalgae such as pyrolysis is a promising approach for the production of bio-oil. However, the pyrolysis oils from algae have inherent problems such as high oxygen- and nitrogen-containing compounds, which have a negative impact on the fuel quality, especially for transportation fuels. In this work, a marine microalga Tetraselmis suecica was pyrolyzed in a fixed-bed reactor in the presence of a Ni supported catalyst to minimize the oxygen and nitrogen content of the pyrolysis oils. A 5% Ni catalyst (Si/Al = 30) was used for the catalytic pyrolysis of algae to oils. The effect of temperature (350-500℃) on the yield of pyrolysis product and the final composition of bio-oil were investigated. The optimum bio-oil composition was achieved at 400℃ with 5% Ni-loaded catalyst and algae to catalyst ratio of 5:1. The pyrolysis oil treated with the catalysts showed high hydrocarbon content of 51.09%. The lowest content of oxygen-containing compounds was 22.79% while the lowest content of nitrogen-containing compounds was 26.12%, indicating that the Ni-loaded catalysts can effectively deoxygenate and denitrogenate pyrolysis oils.