Hoang Vu Ly

Thermogravimetric characteristics and pyrolysis kinetics of Alga Sagarssum sp. biomass.

Alga Sagarssum sp. can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics and kinetics of Sagarssum sp. were investigated using a thermogravimetric analyzer and tubing reactor, respectively. Sagarssum sp. decomposed below 550°C, but the majority of materials decomposed between 200 and 350°C at heating rates of 5-20°C/min. The apparent activation energy increased from 183.53 to 505.57 kJ mol(-1) with increasing pyrolysis conversion. The kinetic parameters of Sagarssum sp. pyrolysis were determined using nonlinear least-squares regression of the experimental data, assuming second-order kinetics. The proposed lumped kinetic model represented the experimental results well and the kinetic rate constants suggested a predominant pyrolysis reaction pathway from Sagarssum sp. to bio-oil, rather than from Sagarssum sp. to gas. The kinetic rate constants indicated that the predominant reaction pathway was A (Sagarssum sp.) to B (bio-oil), rather than A (Sagarssum sp.) to C (gas; C1-C4).

Pyrolysis characteristics and kinetics of the alga Saccharina japonica.

Saccharina japonica can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics of S. japonica were investigated using a thermogravimetric analyzer. Most of the materials decomposed between 200°C and 350°C at heating rates of 10-20°C/min. The apparent activation energy increased from 102.5kJmol(-1) to 269.7kJmol(-1) with increasing pyrolysis conversion. The kinetic parameters of S. japonica pyrolysis were determined using nonlinear least-squares regression of the experimental data assuming first-order kinetics. The kinetic rate constants indicated that the predominant reaction pathway was B (bio-oil) to C (gas; C(1)-C(4)), rather than A (S. japonica) to B (bio-oil) and/or to C (gas; C(1)-C(4)). The proposed lumped kinetics of S. japonica pyrolysis offers a guide for the scale-up of the process at the research and industrial level.

Catalytic Pyrolysis of Alga Saccharina japonica Using Co/γ-Al2O3 and Ni/γ-Al2O3 Catalyst

The catalytic pyrolysis of Saccharina japonica was investigated over Co and Ni catalyst supported on porous γ-Al2O3 in a tubing reactor. Both catalysts were found to exhibit a significant effect on the yield of bio-oil. The bio-oil derived from the pyrolysis consists primarily of dianhydromannitol and other compounds that can be an important source of liquid fuel. In the presence of 5 wt% Co/γ-Al2O3 catalyst with 2 wt% catalyst loading, the yield of the bio-oil from pyrolysis of S. japonica was enhanced remarkably to 40.7 wt% at a relatively low reaction temperature of 380°C within a short period of time (5 min).

Gasification Characteristics of Pinus rigida (Pitch Pine) and Quercus variabilis (Oriental Oak) with Dolomite Catalyst in a Fluidized Bed Reactor

In this study, coniferous (pitch pine, Pinus rigida) and broad-leaved (Oriental oak, Quercus variabilis) trees were gasified in a bubbling fluidized bed reactor, and the effects of reaction temperature and catalyst species on product yields and selectivities were systematically investigated. Upon increasing the gasification temperature from 800 to 900°C, the gas yield of P. rigida maintained similar values at 75.15–78.41%, while the gas yield of Q. variabilis decreased from 71.05 to 58.15% and the char and oil yields increased. The composition of gaseous products was affected according to catalyst species. When dolomite-based catalysts were used for fog biomass gasification, the hydrogen fraction increased substantially, while the carbon monoxide fraction decreased.