Effects of water-washing <i>Saccharina japonica</i> on fast pyrolysis in a bubbling fluidized-bed reactor

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The pyrolysis characteristics of non-edible <I>Saccharina japonica</I> (<I>S. japonica</I>) obtained from an offshore high-density aquaculture facility were systematically investigated using a thermogravimetric analyzer and a bubbling fluidized-bed reactor. As high mineral contents in <I>S. japonica</I> cause ash fouling or agglomeration of char and bed material in fluidized-bed reactor, <I>S. japonica</I> was water-washed as pre-treatment to remove minerals and sticky materials. The pretreated <I>S. japonica</I> samples were mostly decomposed between 200 and 350 °C at heating rates of 5–20 °C/min. The calculated activation energy increased from 36.31 to 393.01 kJ/mol when pyrolysis conversion increased from 5 to 60%. The yields of bio-oil were 25.57–31.27 wt% under the investigated pyrolysis conditions (temperature: 350–450 °C; fluidization velocity: 2.0 × U<SUB>mf</SUB> − 4.5 × U<SUB>mf</SUB>). The highest bio-oil yield (31.27 wt%) from water-washed <I>S. japonica</I> was obtained at 375 °C and 4.0 × U<SUB>mf</SUB>, and the HHVs of the organic and aqueous phases in the bio-oil were 31.47 and 5.41 MJ/kg, respectively. The major compounds in the bio-oil were analyzed by GC-MS and the carbon number distribution of the bio-oils was determined through simulated distillation by TGA.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pyrolysis characteristics and activation energy of water-washed <I>S. japonica</I> were investigated. </LI> <LI> Fast pyrolysis of water-washed <I>S. japonica</I> was carried out in a bubbling fluidized-bed reactor. </LI> <LI> The highest bio-oil yield of 31.27 wt% was obtained at 350 °C and 4.0 U<SUB>mf</SUB>. </LI> <LI> The HHVs of the organic and aqueous bio-oils were 31.47 and 5.41 MJ/kg, respectively. </LI> </UL> </P>