scholarly journals Thermolysis and Kinetics of Scrap Tyre and Bagasse for Energy Utilization

2013 ◽  
Vol 34 (2) ◽  
pp. 94-101
Author(s):  
Petro Ndalila ◽  
Cuthbet F. Mhilu ◽  
Geoffrey R. John
Keyword(s):  
Activation Energy ◽  
Energy Demand ◽  
Energy Production ◽  
Energy Content ◽  
Combustion Process ◽  
High Energy ◽  
Energy Utilization ◽  
Exponential Factor ◽  
Gasification Process ◽  
Kinetics Of

The increase of energy demand has brought concern to find alternative fuel that will at least sustain the requirement. Bagasse and scrap tyre are waste generated in our industrial activities, which can be used in energy production to subsidize the demand. This paper, aim to study the decomposition behaviour and kinetics of biomass (bagasse) and scrap tyre as preliminary stage of fuel sample analysis to be considered for energy production in gasification/combustion or pyrolysis facilities. The behaviour demonstrated with thermogravimetric analyzer (TGA), shows that all samples have high volatile amount release, 84.21% for bagasse and 85.08% for scrap tyre, which means all are suitable for pyrolysis. However, scrap tyre is most suitable for gasification or combustion due to its high energy content, high ash content and low moisture than bagasse. The determined kinetic parameter were activation energy (E) and pre-exponential factor (A) for hemicellulose/oil as first release composite and cellulose/elastomer as second composite of the analyzed bagasse/scrap tyre samples. The hemicelluloses of bagasse exhibited highest value of activation energy and pre-exponential factor (E=178.191 kJ/mol, and A=1.74×10 16 ) than oil of scrap tyre (E=41.113 kJ/mol, and A= 495.5), which means bagasse is suitable candidate for gasification process due to high operating temperature. With this respect of the study, all candidates may be suitable for pyrolysis or gasification/combustion process. However, for environmental consideration scrap tyre is not suitable due to high sulphur (S) and nitrogen (N) content resulting to high emission ofSOX and NOX .

Mechanisms and kinetics of initial pyrolysis and combustion reactions of 1,1-diamino-2,2-dinitroethylene from density functional tight-binding molecular dynamics simulations

2019 ◽  
Vol 97 (11) ◽  
pp. 795-804 ◽  
Author(s):  
Dong Xiang ◽  
Weihua Zhu
Keyword(s):  
Activation Energy ◽  
Molecular Dynamics ◽  
Density Functional ◽  
Tight Binding ◽  
Combustion Process ◽  
Exponential Factor ◽  
Three Stages ◽  
Dynamics Simulations ◽  
Combustion Processes ◽  
Kinetics Of

The density functional tight-binding molecular dynamics approach was used to study the mechanisms and kinetics of initial pyrolysis and combustion reactions of isolated and multi-molecular FOX-7. Based on the thermal cleavage of bridge bonds, the pyrolysis process of FOX-7 can be divided into three stages. However, the combustion process can be divided into five decomposition stages, which is much more complex than the pyrolysis reactions. The vibrations in the mean temperature contain nodes signifying the formation of new products and thereby the transitions between the various stages in the pyrolysis and combustion processes. Activation energy and pre-exponential factor for the pyrolysis and combustion reactions of FOX-7 were obtained from the kinetic analysis. It is found that the activation energy of its pyrolysis and combustion reactions are very low, making both take place fast. Our simulations provide the first atomic-level look at the full dynamics of the complicated pyrolysis and combustion process of FOX-7.

scholarly journals Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  
Keyword(s):  
Activation Energy ◽  
Acid Hydrolysis ◽  
Energy Production ◽  
Combustion Process ◽  
Operating Conditions ◽  
Raw Material ◽  
Energy Of Combustion ◽  
Increasing Temperature ◽  
Hydrolysis Of ◽  
Chamaecytisus Proliferus

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

scholarly journals Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  
Keyword(s):  
Activation Energy ◽  
Waste Management ◽  
Energy Demand ◽  
Power Plants ◽  
Combustion Process ◽  
Isoconversional Methods ◽  
Low Rank ◽  
Heating Rates ◽  
Average Activation Energy ◽  
Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

Kinetics and Activation Parameters for the Alkaline Aqueous Rearrangement of Trichorfon [O,O-Dimethyl-(2,2,2-Trichloro-1-Hydroxyethyl) Phosphonate] to Dichlorvos [O,O-Dimethyl-O-(2,2-Dichloroethenyl)Phosphate]

2001 ◽  
Vol 36 (3) ◽  
pp. 589-604 ◽  
Author(s):  
Julian M. Dust ◽  
Christopher S. Warren
Keyword(s):  
Activation Energy ◽  
High Pressure ◽  
Activation Parameters ◽  
Base Catalysis ◽  
Rearrangement Product ◽  
Exponential Factor ◽  
First Order ◽  
Pseudo First Order ◽  
Order Plot ◽  
Kinetics Of

Abstract The kinetics of the alkaline rearrangement of O,O-dimethyl-(2,2,2-trichloro-1- hydroxyethyl)phosphonate, (trichlorfon, 1), the active insecticidal component in such formulations as Dylox, was followed at 25±0.5°C by high pressure liquid chromatography (UV-vis detector, 210 nm). The rearrangement product, O,Odimethyl- O-(2,2-dichloroethenyl)phosphate (dichlorovos, 2), which is a more potent biocide than trichlorfon, undergoes further reaction, and the kinetics, consequently, cannot be treated by a standard pseudo-first-order plot. A two-point van't Hoff (initial rates) method was used to obtain pseudo-first-order rate constants (kѱ) at 25, 35 and 45°C: 2.6 × 10-6, 7.4 × 10-6 and 2.5 × 10-5 s-1, respectively. Arrhenius treatment of this data gave an activation energy (Ea) of 88 kJ·mol-1 with a pre-exponential factor (A) of 5.5 × 109 s-1. Kinetic trials at pH 8.0 using phosphate and tris buffer systems show no buffer catalysis in this reaction and indicate that the rearrangement is subject to specific base catalysis. Estimates are reported for pseudo-first-order half-lives for trichlorfon at pH 8.0 for environmental conditions in aqueous systems in the Corner Brook region of western Newfoundland, part of the site of a recent trichlorfon aerial spray program.

scholarly journals THE KINETICS OF CaO ASSISTED PATTUKKU CHARCOAL STEAM GASIFICATION

REAKTOR ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 16
Author(s):  
Takdir Syarif ◽  
H Sulistyo ◽  
Wahyudi B Sediawan ◽  
B Budhijanto
Keyword(s):  
Activation Energy ◽  
Tubular Reactor ◽  
Steam Gasification ◽  
Effect Of Temperature ◽  
Composition Analysis ◽  
Zone Model ◽  
Kinetics Parameters ◽  
Exponential Factor ◽  
Surface Diffusivity ◽  
Gasification Process

Abstract Coal is a solid fuel that can be converted into syngas through gasification process. To obtain optimum gasification process design and operation, in-depth understanding of the influential parameters is required. This study aims to investigate the effect of temperature on the gasification process and to obtain its kinetics parameters. The study was carried out in a tubular reactor equipped with a heater and a condenser. Steam was used as gasifying agent, while CaO was employed as a CO2 adsorbent. The charcoal from coal was subjected to gasification at temperatures of 600°C, 700°C, and 800°C. The ratio of charcoal and CaO was 1:1. The gasification process lasted for 60 minutes with gas sample was taken every 15 minutes for composition analysis. The results showed that a temperature increase of 100°C caused a proportional increase of conversion of about 75% higher. The value of activation energy (Ea) and exponential factor (ko) were 46.645kJ/mole and 328.3894/min, respectively. For mass transfer parameters, values of activation energy for surface diffusion (Es) and surface diffusivity factor (as) were 81.126 kJ/mole and 0.138/min, respectively. Keywords: gasification; mathematical model; Pattukku coal char; steam; Thin Reaction Zone Model

Performance and Emission Characteristics of Diesel Engine Running on Blended Palm Oil

2013 ◽  
Vol 795 ◽  
pp. 164-169 ◽  
Author(s):  
A.M. Iqbal ◽  
Z.A. Zainal ◽  
M. Mazlan ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
M.S. Salim
Keyword(s):  
Diesel Engine ◽  
Palm Oil ◽  
Energy Demand ◽  
Fossil Fuel ◽  
Energy Content ◽  
High Energy ◽  
Emission Characteristics ◽  
Performance And Emission ◽  
Suitable Climate ◽  
New Energy

Rapid increasing of industrialization and motorization has led arising of petroleum and energy demand. This pursue a new energy blends to cater the depletion of fossil fuel and the environmental degradation condition. Malaysia is blessed, which has suitable climate to plant alternative fuel (palm oil) and become one of the largest exporters to the world. Palm oil in its refined form as cooking oil has high energy content which can be adopted as an alternative to the petroleum based fuel. This paper evaluates the performance and emission characteristics of refined palm oil (RPO) as a fuel to the diesel engine. Palm oil and its blends composition with 20%, 40%, 60% as well as pure palm oil (100%) and diesel were tested separately under various engine loads. Five series of tests data on each type of fuel were analyzed and compared. Moreover, by increasing the percentage of RPO in blends would lead a character of higher percentage in density and viscosity. Studied revealed that the small percentage of RPO composition promises a good thermal efficiency together with the emission released.

scholarly journals Experimental and CFD analysis of rotary multi vane expander for small capacity generation

2018 ◽  
Vol 204 ◽  
pp. 06007
Author(s):  
Mohammad Mahardika
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Energy Demand ◽  
Energy Production ◽  
Energy Content ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Population Increase ◽  
Cfd Analysis

Every year, Indonesia's population increase so as energy demand. To fulfill Indonesia's energy needs, the capacity of energy production should be increased. Indonesia government has made a solution by propose 35.000 MW program to increase energy production and electrification ratio in Indonesia. An insulated area where electricity did not reach, has many problem to get electricity such as limited infrastructure, low fuel energy content, and expensive turbine. To solve these problem, multi-vane expander (MVE) can be used to extract the low energy and is cheap. MVE have many advantages such as cheap, easy to manufacture, able to operate with 2 phase, and able to low speed operation. But, the disadvantage of this type of expander is leakage. In this paper, experimental and CFD analysis of MVE are conducted. The experiment generated power of 25.7 watt with isentropic and volumetric efficiency of 11.6% and 11.7% by using operating condition of 1.5 bar, 115.6 °C, 626 rpm, and mass flow rate of 80 kg/h. The CFD model of the expander is created with the same dimension and operating conditions as experimental. The result for isentropic efficiency is inversely proportional with mass flow rate and for volumetric efficiency, power, and expander rotation are directly proportional with mass flow rate.

scholarly journals Investigation of Non-Isothermal Kinetics and Thermodynamic Parameters for the Pyrolysis of Different Date Palm Parts

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6553
Author(s):  
Emmanuel Galiwango ◽  
Ali H. Al-Marzuoqi ◽  
Abbas A. Khaleel ◽  
Mahdi M. Abu-Omar
Keyword(s):  
Activation Energy ◽  
Thermodynamic Parameters ◽  
Date Palm ◽  
Energy Content ◽  
High Energy ◽  
Biomass Energy ◽  
Isothermal Kinetics ◽  
Potential Candidate ◽  
Heating Rates ◽  
Average Percentage

Using the thermalgravimetric technique, we investigated the non-isothermal combustion kinetics of abundant and low-cost date palm wastes (leaflet, rachis, fibers, and their composite) as potential biomass energy sources. The kinetic and thermodynamic parameters were determined by Flynn–Wall–Ozawa (FWO), Kissinger–Akahila–Sunose (KAS), and Starink methods. Thermogravimetric analysis results showed a major peak for the degradation of volatiles between 127–138 °C with average percentage mass loss of 68.04 ± 1.5, 65.57 ± 0.6, 62.97 ± 5.5, and 59.26 ± 3.2, for rachis, composite, leaflet, and fibers, respectively. The FWO model showed the lowest activation energy, Eα, of 157 ± 25.6, 158 ± 25.7, 164 ± 40.1, and 169 ± 51.8 kJ mol−1 for the composite, rachis, leaflet, and fibers, respectively. The positive enthalpy values confirmed an endothermic pyrolysis reaction. For all models, a minimal difference of 4.40, 5.57, 6.55, and 7.51 kJ mol−1 between activation energy and enthalpy for rachis, fibers, composite, and leaflet ensued, respectively. The KAS model was best suited to describe chemical equilibrium with average ΔG values of 90.3 ± 28.8, 99.3 ± 34.9, 178.9 ± 27.3, and 186.5 ± 38.2 kJ mol−1 for rachis, fibers, composite, and leaflet, respectively. The reaction mechanism by the Malek and Popescu methods was ((g(α)=[−ln(1−α)]14) across the conversion range of 0.1–0.9 for all heating rates. The high energy content and volatile matter combined with low energy barriers make date palm waste a potential candidate in a biorefinery.

scholarly journals The kinetics of the extraction of caffeine from guarana seed under the action of ultrasonic field with simultaneous cooling

2019 ◽  
Vol 9 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Biljana Koturevic ◽  
Borivoj Adnadjevic ◽  
Jelena Jovanovic
Keyword(s):  
Activation Energy ◽  
Kinetic Parameters ◽  
Reaction System ◽  
Ultrasonic Field ◽  
Conventional Heating ◽  
Isothermal Kinetics ◽  
Correlation Relationship ◽  
Exponential Factor ◽  
Caffeine Extraction ◽  
Kinetics Of

AbstractThe kinetics of isothermal extraction of caffeine from guarana seed under the action of ultrasonic field with simultaneous cooling (UESC) was investigated. The isothermal kinetics curves were measured at temperatures range T = 17-58°C. Using the model-fitting method it was determined that the kinetics of caffeine extraction can be described by a theoretical Jander three-dimensional diffusional model. The values of the rate constant were calculated for different temperatures, as well as the kinetic parameters (activation energy (Ea) and pre-exponential factor (lnA)). Based on the results obtained, it is concluded that the rate constants of caffeine extraction under UESC are about 2 times higher in comparison to the values obtained for the extraction in the conditions of conventional heating (CH). The activation energy of the caffeine extraction under the UESC $\left( E_{\text{a}}\,^{\text{UESC}}=19.4\,\text{kJ}\cdot \text{mo}{{\text{l}}^{-1}} \right)$is lower than the values are for CH $\left( E_{\text{a}}\,^{\text{CH}}=21.8\,\text{kJ}\cdot \text{mo}{{\text{l}}^{-1}} \right).$Energy consumption for UESC is four times lower than for CH conditions. It is shown that there is a linear correlation relationship between kinetic parameters obtained for UESC and CH conditions. The changes in the values of kinetic parameters are explained by the model of selective transfer of energy from the reaction system to the reactant molecules.

Macro Kinetics of N-Phosphonomethyliminodiacetic Acid Catalytic Oxidation

2012 ◽  
Vol 455-456 ◽  
pp. 872-879 ◽  
Author(s):  
Yan Bao ◽  
Jia Wu ◽  
Xiao Ping Hu
Keyword(s):  
Activation Energy ◽  
Kinetic Model ◽  
Measured Data ◽  
Second Step ◽  
Oxidizing Agent ◽  
Dissolved Oxygen Concentration ◽  
Exponential Factor ◽  
In Series ◽  
Kinetics Of ◽  
Made In

The oxidation of N-phosphonomethyliminodiacetic acid (PMIDA) to prepare glyphosate (PMG) over active carbon was investigated. Experiments were carried out with O2 as the oxidizing agent in a 150-mL autoclave made in stainless steel, with reaction temperature ranging from 323.15 to 353.25K and the pressure from 0.12 to 0.40 MPa. The macro kinetic model of the reactions in series was developed, and the pre-exponential factor and activation energy were estimated from the measured data in experiments. The influence of dissolved oxygen concentration was also considered in this macro kinetic model. The results indicated that the two step reactions are all one-order to reactant (PMIDA or PMG) and 0.3 or 0.07 to O2 respectively. The active energy was 12.98kJ/mol for the first step reaction and 10.87kJ/mol for the second step reaction.

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