scholarly journals Kinetic analysis of oil palm empty fruit bunch (OPEFB) pellets as feedstock for pyrolysis

2015 ◽  
Author(s):  
Bemgba Bevan Nyakuma
Keyword(s):  
Activation Energy ◽  
Oil Palm ◽  
Room Temperature ◽  
Energy Requirement ◽  
Inert Atmosphere ◽  
Decomposition Kinetics ◽  
The Other ◽  
Empty Fruit Bunch ◽  
Heating Rates ◽  
Kinetics Of

The thermal behaviour and decomposition kinetics of pelletized oil palm empty fruit bunch (OPEFB) was investigated in this study using thermogravimetric analysis (TGA). The OPEFB pellets were heated from room temperature to 1000 ºC at different heating rates; 5, 10 and 20 °C min-1 under inert atmosphere. Thermal degradation occurred in three steps; drying, devolatization and char decomposition. Subsequently, the Popescu method was applied to the TG/DTG data to determine the kinetic parameters of the OPEFB pellets. The activation energy, E, for different degrees of conversion, α = 0.05 to 0.7 are 36.60 kJ/mol to 233.90 kJ/mol with high correlation R2 values. In addition, the drying and decomposition of lignin reactions displayed lower E values compared to the devolatization characterized by high E value of 233 kJ/mol at α = 0.2. This indicates that the devolatization process is slower and requires higher energy requirement to reach completion than the other stages of thermal decomposition of the fuel under inert atmosphere. Keywords: decomposition, kinetics, oil palm, empty fruit bunch, pyrolysis.

scholarly journals Kinetic analysis of oil palm empty fruit bunch (OPEFB) pellets as feedstock for pyrolysis

2015 ◽  
Author(s):  
Bemgba Bevan Nyakuma
Keyword(s):  
Activation Energy ◽  
Oil Palm ◽  
Room Temperature ◽  
Energy Requirement ◽  
Inert Atmosphere ◽  
Decomposition Kinetics ◽  
The Other ◽  
Empty Fruit Bunch ◽  
Heating Rates ◽  
Kinetics Of

The thermal behaviour and decomposition kinetics of pelletized oil palm empty fruit bunch (OPEFB) was investigated in this study using thermogravimetric analysis (TGA). The OPEFB pellets were heated from room temperature to 1000 ºC at different heating rates; 5, 10 and 20 °C min-1 under inert atmosphere. Thermal degradation occurred in three steps; drying, devolatization and char decomposition. Subsequently, the Popescu method was applied to the TG/DTG data to determine the kinetic parameters of the OPEFB pellets. The activation energy, E, for different degrees of conversion, α = 0.05 to 0.7 are 36.60 kJ/mol to 233.90 kJ/mol with high correlation R2 values. In addition, the drying and decomposition of lignin reactions displayed lower E values compared to the devolatization characterized by high E value of 233 kJ/mol at α = 0.2. This indicates that the devolatization process is slower and requires higher energy requirement to reach completion than the other stages of thermal decomposition of the fuel under inert atmosphere. Keywords: decomposition, kinetics, oil palm, empty fruit bunch, pyrolysis.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

scholarly journals Investigation of the pyrolysis characteristics and kinetics of oil-palm solid waste by using Coats–Redfern method

2019 ◽  
Vol 38 (1) ◽  
pp. 298-309
Author(s):  
Fredy Surahmanto ◽  
Harwin Saptoadi ◽  
Hary Sulistyo ◽  
Tri A Rohmat
Keyword(s):  
Activation Energy ◽  
Solid Waste ◽  
Oil Palm ◽  
Frequency Factor ◽  
Nitrogen Atmosphere ◽  
Empty Fruit Bunch ◽  
Pyrolysis Kinetics ◽  
Pyrolysis Characteristics ◽  
Kinetics Of

The pyrolysis kinetics of oil-palm solid waste was investigated by performing experiments on its individual components, including empty fruit bunch, fibre, shell, as well as the blends by using a simultaneous thermogravimetric analyser at a heating rate of 10°C/min under nitrogen atmosphere and setting up from initial temperature of 30°C to a final temperature of 550°C. The results revealed that the activation energy and frequency factor values of empty fruit bunch, fibre, and shell are 7.58–63.25 kJ/mol and 8.045E-02–4.054E + 04 s−1, 10.45–50.76 kJ/mol and 3.639E-01–5.129E + 03 s−1, 9.46–55.64 kJ/mol and 2.753E-01–9.268E + 03, respectively. Whereas, the corresponding values for empty fruit bunch–fibre, empty fruit bunch–shell, fibre–shell, empty fruit bunch–fibre–shell are 2.97–38.35 kJ/mol and 1.123E-02–1.326E + 02 s−1, 7.95–40.12 kJ/mol and 9.26E-02–2.101E + 02 s−1, 9.14–50.17 kJ/mol and 1.249E-01–2.25E + 03 s−1, 8.35–45.69 kJ/mol and 1.344E + 01–4.23E + 05 s−1, respectively. It was found that the activation energy and frequency factor values of the blends were dominantly due to the role of the components with a synergistic effect occurred during pyrolysis.

scholarly journals Modelling of Thermal Decomposition Kinetics of Proteins, Carbohydrates and Lipids Using Scenedesmus microalgae thermal Data

2020 ◽  
Vol 32 (11) ◽  
pp. 2921-2926
Author(s):  
BOTHWELL NYONI ◽  
PHUTI TSIPA ◽  
SIFUNDO DUMA ◽  
SHAKA SHABANGU ◽  
SHANGANYANE HLANGOTHI
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Bulk Material ◽  
Decomposition Kinetics ◽  
Second Order ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
High Heating ◽  
The Individual ◽  
Kinetics Of

In present work, the thermal decomposition behaviour and kinetics of proteins, carbohydrates and lipids is studied by use of models derived from mass-loss data obtained from thermogravimetric analysis of Scenedesmus microalgae. The experimental results together with known decomposition temperature range values obtained from various literature were used in a deconvolution technique to model the thermal decomposition of proteins, carbohydrates and lipids. The models fitted well (R2 > 0.99) and revealed that the proteins have the highest reactivity followed by lipids and carbohydrates. Generally, the decomposition kinetics fitted well with the Coats-Redfern first and second order kinetics as evidenced by the high coefficients of determination (R2 > 0.9). For the experimental conditions used in this work (i.e. high heating rates), the thermal decomposition of protein follows second order kinetics with an activation energy in the range of 225.3-255.6 kJ/mol. The thermal decomposition of carbohydrate also follows second order kinetics with an activation energy in the range of 87.2-101.1 kJ/mol. The thermal decomposition of lipid follows first order kinetics with an activation energy in the range of 45-64.8 kJ/ mol. This work shows that the thermal decomposition kinetics of proteins, carbohydrates and lipids can be performed without the need of experimentally isolating the individual components from the bulk material. Furthermore, it was shown that at high heating rates, the decomposition temperatures of the individual components overlap resulting in some interactions that have a synergistic effect on the thermal reactivity of carbohydrates and lipids.

Decomposition Kinetics of Switchgrass: Estimating Activation Energy

2014 ◽  
Vol 881-883 ◽  
pp. 726-733
Author(s):  
Gui Ying Xu ◽  
Jiang Bo Wang ◽  
Ling Ping Guo ◽  
Guo Gang Sun
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Apparent Activation Energy ◽  
High Purity ◽  
Isoconversional Methods ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Model Free ◽  
Chemical Utilization ◽  
Kinetics Of

TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass.

scholarly journals MICROSTRUCTURAL STUDY AND RECRYSTALLIZATION KINETICS OF DEFORMED COMMERCIAL COPPER WIRES

2018 ◽  
Vol 24 (1) ◽  
pp. 32 ◽  
Author(s):  
Lahcene Fellah ◽  
Abdallah Diha ◽  
Zakaria Boumerzoug
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Argon Atmosphere ◽  
Recrystallization Temperature ◽  
Heating Rates ◽  
Recrystallization Kinetics ◽  
Slip Bands ◽  
Commercial Copper ◽  
The One ◽  
Kinetics Of

This work aims to investigate the microstructure after cold-wiredrawing process of commercial copper and its recrystallization kinetics under isochronal annealing. In this paper, the samples studied are commercial copper wires reduced at six different reductions by a wiredrawing at room temperature. Optical microscopy, Scanning Electron Microscopy (SEM), and DSC were used as characterization techniques. The samples were annealed under Argon atmosphere with four different heating rates by using DSC. The Kissinger, Ozawa, Boswell, and Starink methods were used to determine the recrystallization kinetics. The results showed that the cold-wiredrawing had caused the elongation of grains along the main axis of the wires also showed the existence of slip bands. It has been found, on the one side, that the recrystallization temperature increased and shifted to higher temperatures as the heating rate increased, which means that this reaction is thermally actived; On the other sidethe recrystallization temperature clearly shifted to lower temperatures as the deformation increased, which indicated that recrystallization is profoundly enhanced by high deforming.We noted a decrease in the activation energy values when the reduction increases, the activation energy for the most reduced materials were lower than that in the less reduced wires.

Decomposition kinetics of cobalt complexes of phenoxy radicals studied by EPR method

1980 ◽  
Vol 45 (2) ◽  
pp. 464-474 ◽  
Author(s):  
Ladislav Omelka ◽  
Alexander Tkáč
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Effective Activation Energy ◽  
Decomposition Kinetics ◽  
Peroxy Radicals ◽  
Substitution Reactions ◽  
Phenoxy Radicals ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Homolytic Substitution

In bimolecular homolytic substitution reactions type SH2 between coordinated peroxy radicals [Co(III)]RO2 and partially hindered bisphenol 4,4'-thiobis-(3-methyl-6-tert-butylphenol) (an antioxidant with commercial name Santonox R) in non-polar medium at room temperature an equilibrium is established between free and Co(III)-coordinated phenoxy radicals. Increasing temperature shifts the equilibrium in favour of the decomplexed free radicals. The complexation-decomplexation process of phenoxy radicals is practically reversible up to 90°C. Polar coordinating solvents (methanol, H2O, diethyl ether, tetrahydrofurane) displace irreversibly the radicals from the complexes. From their decomposition kinetics at various temperatures activation energy of decomplexation by methanol has been determined (110 ± 8 kJ mol-1). The displaced free partially hindered phenoxy radicals are not sufficiently stable and undergo subsequent radical transformations (dimerization, intramolecular and intermolecular H-transfer) with effective activation energy about 67 kJ mol-1.

scholarly journals Distributed Activation Energy Model for Thermal Decomposition of Polypropylene Waste

2021 ◽  
pp. 179-187
Author(s):  
S. Kartik ◽  
Hemant K. Balsora ◽  
Abhishek Sharma ◽  
Anand G. Chakinala ◽  
Abhishek Asthana ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Energy Model ◽  
Decomposition Kinetics ◽  
Fuel Oil ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Distributed Activation Energy Model ◽  
Municipal Plastic Waste ◽  
Kinetics Of

AbstractThermal decomposition kinetics of Polypropylene (PP) waste is extremely important with respect to valorisation of waste plastics and production of utilizable components viz. chemicals, fuel oil & gas. The present research study focuses on pyrolysis kinetics of PP waste, which is present as a fraction of municipal plastic waste through distributed activation energy model (DAEM). The decomposition kinetics for PP follows a Gaussian distribution, where the normal distribution curves were centred corresponding to activation energy of 224 kJ/mol. The standard deviation of the distribution for the PP sample was found to be 22 kJ/mol indicating its wider distribution of decomposition range. The data validation has been carried out by comparing the rate parameter and extent of conversion values calculated through DAEM model with the Thermogravimetric analysis (TGA) experiments carried out for PP at various heating rates of 5, 10, 20 and 40 °C/min.

Pyrolytic Characteristics and Kinetics of Xanthoceras Sorbifolia Oil

2012 ◽  
Vol 178-181 ◽  
pp. 1093-1096
Author(s):  
Quan Cheng Zhou ◽  
Gui Hua Sheng
Keyword(s):  
Activation Energy ◽  
Reaction Rates ◽  
Inert Atmosphere ◽  
Probable Mechanism ◽  
Heating Rates ◽  
Moisture Evaporation ◽  
Average Activation Energy ◽  
Exponential Factors ◽  
Three Stages ◽  
Kinetics Of

The pyrolytic characteristics and kinetics of Xanthoceras sorbifolia oil were investigated pyrolysis in indifferent atmosphere and at heating rates of 10, 20 and 30 °C min-1 in an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO and KAS methods. Three stages appeared during pyrolysis: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the X. sorbifolia oil were observed. Stage II of the X. sorbifolia oil could be described by the Avramic- Erofeev equation 20 (n=4). The average activation energy of X. sorbifolia oil was 353 kJ mol-1

Evalution of the Pyrolytic and Kinetics Characteristics of Xanthoceras sorbifolia Oil

2012 ◽  
Vol 512-515 ◽  
pp. 401-404
Author(s):  
Gui Hua Sheng ◽  
Quan Cheng Zhou ◽  
De Mao Li
Keyword(s):  
Activation Energy ◽  
Reaction Rates ◽  
Inert Atmosphere ◽  
Heating Rates ◽  
Moisture Evaporation ◽  
Average Activation Energy ◽  
Power Equation ◽  
Exponential Factors ◽  
Three Stages ◽  
Kinetics Of

The pyrolytic characteristics and kinetics of Xanthoceras sorbifolia oil were investigated at heating rates of 10, 20 and 30 °C min-1in an inert atmosphere. The most probable mechanism function and activation energy pre-exponential factors were calculated by the Popescu, FWO and KAS methods. Three stages appeared during pyrolysis: moisture evaporation, primary devolatilization and residual decomposition. Significant differences in the average activation energy, thermal stability, final residuals and reaction rates of the X. sorbifolia oil at different heating rate were observed. Stage II of the X. sorbifolia oil could be described by the Mampel Power equation 22 (n=0.25). The average activation energy of X. sorbifolia oil was 346 kJ mol-1.

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