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Abstract  

Combustion experiments of three typical seaweeds (Gracilaria cacalia, Enteromorpha clathrata and Laminaria japonica) have been studied using a DTA-60H Thermal Analyzer and the combustion processes and characteristics are studied. Thermogravimetric experiments are carried out on the samples with 0.18 mm particle size at the heating rate of 20°C min−1. The results indicate that the ignition mode of seaweed is homogeneous and the combustion process is composed of dehydration, the pyrolysis and combustion of volatile, transition stage, the combustion of char as well as the reaction at high temperature. And the combustion characteristic parameters are obtained such as ignition temperature, maximum rate of combustion, burnout temperature etc. The combustion models of these seaweeds are also analyzed. The combustion characteristics and model differences between the seaweed and woody biomass are caused by the differences of volatile components. The combustibility indexes of seaweeds calculated are better than that of woody biomass, and the index of Gracilaria cacalia is the best. At last, activation energies are determined using Arrhenius model that is solved by binary linear regression method.

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Abstract  

TG and DTA experiments were performed to investigate the biomass tar combustion behavior in coexistence of dolomite and mayenite at two different heating rates as 5 and 15°C min−1. Different reaction kinetic mechanisms with the classical Arrhenius model were used to treat TG data, and showed that the first-order combustion model fitted the data well. Three stages combustion model was proposed and applied for the calculation of kinetics parameters successfully. The starting temperature of high temperature combustion stage moved up near 100°C because of the coexistence catalysts, and the combustion amount of biomass of the stage also improved nearly 10 mass%. By calculation a uniform trend of decreasing activation energies was observed with the addition of dolomite and mayenite, and also greatly improved the amount and speed of tar combustion process.

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Abstract

Thermogravimetry (TG) and differential thermal analysis were used to investigate combustion behavior with the addition of cornstalk to coal powder and coal tar at three different heating rates: 5, 10, and 15 °C min−1. Different reaction kinetic mechanisms with the classical Arrhenius model were used to treat TG data. The first-order combustion model fitted the data well. The combustion characteristics of the two masses were analyzed according to combustion characteristics parameters such as ignition temperature, peak temperature at maximum weight loss rate, and burnout temperature, among others. By calculation, a uniform trend of decreasing activation energies was observed with the addition of cornstalk. The rate of coal powder and coal tar combustion process was also greatly improved.

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Abstract

Detailed kinetic models dominate in combustion modeling. However, their application is often complicated by insufficient knowledge of a mechanism and reaction rates for heterophase interactions especially as applied to gasification. The novel approach using thermodynamic model of extreme intermediate states (MEIS) could make up an efficient alternative. MEIS is strictly deterministic and simple in structure. Along with the search for the final equilibrium, it allows partial equilibria to be found and various macroscopic phenomena to be taken into account, e.g., transport phenomena and kinetic rates. The core problem in MEIS construction is formulation of macrokinetic constrains whose form depends on the problem statement and accessible information on the process. Thermal analysis has been deployed to infer proper constraints for modeling of wooden biomass gasification. The advantage of the method consists in much higher availability of the initial information compared with detailed kinetics. Model results are in good agreement with experiment.

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-based propellants the oxidizer binder gas reactions occur too far from the burning surface to influence to any great extent the heat transfer to the surface. Carvalheira and Campos [ 19 ] proposed combustion model AN–HTPB propellant with the concept of

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BTATz-CMDB propellants

High-pressure thermal properties and their correlation with burning rates

Journal of Thermal Analysis and Calorimetry
Authors: Jian-Hua Yi, Feng-Qi Zhao, Ying-Hui Ren, Bo-Zhou Wang, Cheng Zhou, Xiao-Ning Ren, Si-Yu Xu, Hai-Xia Hao and Rong-Zu Hu

little changed, and the kinetic equations have a little difference between the two propellants. Correlation between PDSC characteristic values and burning rates On the combustion models for solid propellant, Miller et

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