Thermogravimetric characteristics and pyrolysis kinetics of high-density-aquacultured Saccharina Japonica: Effects of water-washing

The thermogravimetric characteristics and pyrolysis kinetics of high-density-aquacultured Saccharina japonica were investigated using a thermogravimetric analyzer and micro-tubing reactor, respectively. The effect of water washing S. japonica samples on pyrolysis product distribution was studied at 360, 370 and 380 °C with various residence times from 1.0 to 3.0 min. The kinetic rate constants of pyrolysis for untreated and water-washed S. japonica samples were determined using nonlinear least-squares regression of experimental data assuming first-order kinetics. The predominant reaction pathway of water-washed S. japonica was liquid to gas product (k3) at each temperature, while that of untreated S. japonica was biomass to liquid product (k2) at 360 and 370 °C, then liquid to gas product (k3) at 380 °C. However, the k2/k1 ratio of water-washed S. japonica (1.2166-1.3247) was more than two times that of untreated S. japonica (0.5763-0.6346).