title: Thermogravimetric kinetic study of agricultural residue biomass pyrolysis based on combined kinetics.
abstract: Pyrolytic kinetic of an agricultural residue (AR) feedstock, a mixture of plants (cotton, wheat, rich, corn) stems, was investigated based on combined kinetics. The most suitable mechanism for AR one-step pyrolysis was f(α)=(1-α)(1.1816)α(-1.8428) with kinetic parameters of: apparent activation energy 221.7kJ/mol, pre-exponential factor 4.17E16s(-1). Pyrolysis of AR feedstock could not be described by one-step reaction attributes to heterogeneous features of pyrolysis processes. Combined kinetics three-parallel-reaction (CK-TPR) model fitted the pyrolysis experimental data very well. Reaction mechanisms for pseudo hemicelluloses, cellulose, lignin in CK-TPR model was f(α)=(1-α)(1.6244)α(-0.3371)[-ln(1-α)](-0.0515), f(α)=(1-α)(1.0597)α(-0.6909)[-ln(1-α)](0.9026) and f(α)=(1-α)(2.9577)α(-4.7719), respectively. Apparent activation energy of three pseudo components followed the order of Elignin(197.3kJ/mol)>Ecellulose(176.3kJ/mol)>Ehemicelluloses (151.1kJ/mol). Mechanism of hemicelluloses pyrolysis could be further expressed as f(α)=(1-α)(1.4). The pyrolytic mechanism of cellulose met the Nucleation well. However, mechanism of lignin pyrolysis was complex, which possibly was the combined effects of Nucleation, Diffusion, Geometrical contraction, and Power law.
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Xun
authors: X
authors: Wang
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Mian
authors: M
authors: Hu
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Wanyong
authors: W
authors: Hu
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Zhihua
authors: Z
authors: Chen
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Shiming
authors: S
authors: Liu
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Zhiquan
authors: Z
authors: Hu
authors: School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: xiaobo1958@hust.edu.cn.
authors: Bo
authors: B
authors: Xiao
mesh_terms: D018533:Biomass; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D018556:Crops, Agricultural / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D008962:Models, Theoretical; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D013818:Thermogravimetry
chemical_list: D011134:Polysaccharides; C007916:hemicellulose; D002482:Cellulose; D008031:Lignin
keywords: Agricultural residue; Combined kinetics; Pyrolysis; Thermo-gravimetric analysis