Fast hydrothermal liquefaction of a Norwegian macro-alga: Screening tests

Hydrothermal liquefaction of sugar kelp Laminaria saccharina, a brown macro-alga harvested in Trondheim bay (Norway), was experimentally studied by a high-throughput screening technique using sealed quartz capillary reactors. Very high heating rates were achieved by the experiment technique, which significantly intensified the liquefaction and resulted in much higher bio-oil yields. The highest bio-oil yield of 79% w (dry and ash free) was obtained from the test at the highest heating rate of 585 °C/min (temperature = 350 °C, holding time = 15 min, and kelp/water ratio = 1/10 w/w). The HHV of the bio-oil was also significantly improved, being as high as of 35.97 MJ/kg (dry and ash free). In addition, a numerical prediction and modelling supported by regression analyses showed a good agreement between the present study and the literature, with respect to the effect of heating rate on the bio-oil yield.