Research of specific heat capacities of three large seaweed biomass

Abstract

Based on the differential scanning calorimeter (DSC) in traditional solution method, the modification considering the mass loss was put into the measurement of specific heat capacities, which made the measured values more accurately. Adopting this method, the specific heat capacities of three sorts of seaweeds (a kind of marine biomass) during 40–550 °C were measured by the NETZSCH DSC404 DSC. The results showed that the initial temperature of pyrolysis mass loss of seaweed is lower than that of lignocellulosic biomass. The heating process of seaweed could be divided into three intervals: dehydration, devolatilization, and semi-coke state. The differences of the specific heat capacities at three intervals were quite obvious, because the property of residues changed greatly. Generally, the specific heat capacities of three sorts of seaweed obeyed such sequence: Gracilaria cacalia > Enteromorpha clathrata > Sargassum natans. The mathematic relations for specific heat capacities at temperatures ranging 40–550 °C were presented. The results would provide a reference for the thermal chemical conversion energy utilization of seaweed biomass and corresponding numerical simulation.