Extraction of inorganic materials from fresh and dried alga Saccharina japonica

Extraction of minerals from fresh and dried macroalgae kelp (Saccharina japonica) was investigated to get better biomass resource for biorefinery. At a solid to liquid ratio of 1:6 (w/v), 2 h extraction, and 30 °C, inorganic extraction efficiency (Einorg) and total efficiency (Etot) using water were respectively 76.88 and 50.82% for fresh biomass while those of dried biomass were 72.99 and 65.79%. For fresh biomass extraction using ethanol, Einorg (74.19%) and Etot (42.21%) were much higher than for dried biomass with 7.29% Einorg and 1.21% Etot. With 10% ethanol, Einorg were similar for both materials, however, higher ratio of inorganic to organic extraction efficiency (rE) (5.48) were obtained for fresh biomass compared to lower rE (2.02) for dried biomass. The rE for fresh biomass was higher (13.80) than that for dried biomass (1.32) using water at 1:4 solid to liquid ratio, suggesting that fresh kelp is better feedstock for bioenergy production.