scholarly journals An Investigation into the Combustion of Mixed Fuel Consisting of Bituminous Coal and Crude Bio-Oil

2015 ◽  
Vol 773-774 ◽  
pp. 1184-1188
Author(s):  
Hazlin Hamdan ◽  
Munawar Zaman Shahruddin ◽  
Ahmad Rafizan Mohamad Daud ◽  
Syed Shatir A. Syed-Hassan
Keyword(s):  
Gas Flow ◽  
Bituminous Coal ◽  
Decomposition Reaction ◽  
Volatile Matter ◽  
Kinetic Evaluation ◽  
Exponential Factor ◽  
Air Atmosphere ◽  
Coal Fuel ◽  
Bio Oil ◽  
Lower Temperature

The combustion of bituminous coal, bio-oil, and their slurry mixtures were performed under air atmosphere using Thermogravimetric Analyzer (TGA). All samples were run from room temperature to 110°C and held for 10 minutes before the temperature was ramped to 1100°C and held again for 10 minutes at 1100°C at the heating rate of 10°C/min and gas flow rate of 50mL/min. Kinetic evaluation was conducted using a simple Arrhenius-type kinetic model with first-order decomposition reaction. Apparent activation energy, Ea, and pre-exponential factor, A, were calculated from the modelling equation. Results reveal that the reactivity of CBS fuel is higher than a single coal fuel to which the addition of bio-oil helps to increase the combustion performance of the blends. The optimum fuel ratio appears at 50:50 ratio with equal contribution of coal and bio-oil properties that contribute to the increase in volatile matter causing maximum combustion rate achievable at much lower temperature compared to single coal fuel.

Study on Co-Combustion Characteristics of Coals under Pure Oxygen Atmosphere

2011 ◽  
Vol 361-363 ◽  
pp. 882-886
Author(s):  
Ming Yan Gu ◽  
Xu Hui Liu ◽  
Biao Ma ◽  
Jia Xin Li
Keyword(s):  
Activation Energy ◽  
Bituminous Coal ◽  
Volatile Matter ◽  
Combustion Characteristics ◽  
Pure Oxygen ◽  
Burning Process ◽  
Coal Burning ◽  
Air Atmosphere ◽  
Anthracite Coal ◽  
Lower Temperature

In this study, the combustion behaviors of three kinds of coal and their mixtures under the pure oxygen and air atmosphere were studied by using a thermo-gravimetric analyzer. The combustion characteristics such as ignition and burnout behavior were investigated in the temperature from 20°C to 800°C. The influence of mixing Shenhua coal with Huaibei bituminous and Sanming anthracite coal on combustion characteristics was conduced. The results obtained show that pure oxygen content accelerated the coal burning process greatly; the coal volatile matter started to release at a lower temperature and the coal burning process was finished earlier compared with the burning process under the air atmosphere. The addition of Shenhua coal improved the combustion characteristics of both Huaibei bituminous coal and Sanming anthracite in a different way. For the Huaibei bituminous coal, both the ignition and burnout temperature decreased linearly with the increasing ratio of Shenhua coal; while for the Sanming anthracite, the addition of Shenhua coal greatly lowered the mixture ignition temperature, and the burnout temperature was nearly the same. The activation energy of the mixture coal with Shenhua and Huaibei coal reduced with the ratio of Shenhua coal. For the Shenhua and Sanming coal mixture, the activation energy changed differently at the two burning stages.

Arrhenius Kinetic Analysis during Combustion of Spirulina platensis Microalgae

2020 ◽  
Vol 851 ◽  
pp. 142-148
Author(s):  
Sukarni Sukarni ◽  
Muklisul Anwar
Keyword(s):  
Spirulina Platensis ◽  
Volatile Matter ◽  
Differential Method ◽  
Air Flow Rate ◽  
Kinetic Evaluation ◽  
Exponential Factor ◽  
Kinetic And Thermodynamic Parameters ◽  
Second Stage ◽  
Factor Log ◽  
Three Stages

Characteristics and potential of microalgae Spirulina platensis as an energy source were studied in regard to the decomposition patterns, as well as kinetic and thermodynamic parameters. The thermogravimetric analysis was performed using the TGA instrument (Mettler Toledo TG DSC 1) at a heating rate of 30 °C/min, with an atmospheric air flow-rate of 100 ml/min at the temperature range of 25-1000 °C. The kinetic was evaluated using a differential method of Arrhenius. The results showed that Spirulina platensis microalgae decomposed into three stages. The first stage is related to the evaporation of moisture, the second stage is associated with the release of volatile matter, and the final stage is the combustion stage of char. The kinetic evaluation resulted in the respective activation energy (), pre-exponential factor (log A) and reaction order (n) are 53.57 kJ/mol, 4.4 min-1, and 1.73. It also understands from the thermodynamic analysis that the respective values of enthalpy (), Gibbs free energy ( and the entropies ( were 48.50 kJ/mol, 146,73 kJ/mol, and-174,78 J/mol.

scholarly journals Isothermal Kinetic Analysis of the Thermal Decomposition of Wood Chips from an Apple Tree

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 195
Author(s):  
Ivan Vitázek ◽  
Martin Šotnar ◽  
Stella Hrehová ◽  
Kristína Darnadyová ◽  
Jan Mareček
Keyword(s):  
Thermal Decomposition ◽  
Apple Tree ◽  
Combustion Process ◽  
Reaction Model ◽  
Wood Chips ◽  
Small Scale ◽  
Exponential Factor ◽  
Air Atmosphere ◽  
First Order Chemical Reaction ◽  
Isothermal Kinetic

The thermal decomposition of wood chips from an apple tree is studied in a static air atmosphere under isothermal conditions. Based on the thermogravimetric analysis, the values of the apparent activation energy and pre-exponential factor are 34 ± 3 kJ mol−1 and 391 ± 2 min−1, respectively. These results have also shown that this process can be described by the rate of the first-order chemical reaction. This reaction model is valid only for a temperature range of 250–290 °C, mainly due to the lignin decomposition. The obtained results are used for kinetic prediction, which is compared with the measurement. The results show that the reaction is slower at higher values of degree of conversion, which is caused by the influence of the experimental condition. Nevertheless, the obtained kinetic parameters could be used for the optimization of the combustion process of wood chips in small-scale biomass boilers.

A Novel Design for Reduction of Ammonium Bisulfate Deposition in the Rotary Air Preheater

2018 ◽  
Author(s):  
Yufan Bu ◽  
Limin Wang ◽  
Xiaoyang Wei ◽  
Lei Deng ◽  
Defu Che
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Catalytic Reduction ◽  
Operating Cost ◽  
Reaction Chamber ◽  
Air Preheater ◽  
Accurate Temperature ◽  
Ammonium Bisulfate ◽  
Lower Temperature ◽  
Novel Design

Nitrogen oxide (NOx) emitted from boilers in coal-fired power plant may be reduced by 90 percent through the application of the selective catalytic reduction (SCR). However, the escaped ammonia from the SCR systems could react with sulfur oxides (SOx) in the flue gas to form ammonium bisulfate (ABS) in exhaust systems. The blockage and corrosion caused by ABS seriously impact the rotary air preheater (RAPH), which would not only increase operating cost on ash-blowing and cleaning but also lead to unplanned outage. To solve the problem, in this paper a novel preheater system is proposed. A single preheater is split into two sub-preheaters, between which the main flue gas flow is mixed with the recirculated flue gas from outlet of the lower-temperature preheater. After the mixing point, a reaction chamber and a precipitator are installed. A numerical finite difference method (FDM) is employed to model the RAPH and obtain the accurate temperature distribution of fluid and heat transfer elements. The initial formation temperatures of (NH4)2SO4 and ABS are 200 °C and 170 °C, respectively, according to the flue gas composition in this work. By calculation, this split design of the RAPH is believed to be effective in reducing deposition of ABS.

High Temperature Stability of MGCs Gas Turbine Components in Air and Combustion Gas Flow Environments

2004 ◽  
Author(s):  
Narihito Nakagawa ◽  
Hideki Ohtsubo ◽  
Kohji Shibata ◽  
Atsuyuki Mitani ◽  
Kazutoshi Shimizu ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Temperature Stability ◽  
High Temperature Strength ◽  
High Temperature Stability ◽  
Combustion Gas ◽  
Air Atmosphere ◽  
Low Nox Emission ◽  
Very High

Melt growth composites (MGCs) have a unique microstructure, in which continuous networks of single-crystal phases interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, oxidation resistance and thermal stability in an air atmosphere at very high temperature. To achieve ultra-high thermal efficiency and low NOx emission for gas turbine systems, non-cooled turbine nozzle vanes and heat shield panels of combustor liners has been fabricated on an experimental basis. These components are thermally stable after heat treatment at 1700°C for 1000 hours in an air atmosphere. In addition, we have just started the exposure tests to evaluate the influence of combustion gas flow environment on MGCs.

scholarly journals PERBANDINGAN NILAI BAKAR BRIKET BATUBARA DAN BRIKET ARANG (CAMPURAN CANGKANG BINTARO (Cerbera Manghas) DAN BAMBU BETUNG (Dendrocalamus Asper)

2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Ida Febriana ◽  
Zurohaina Zurohaina ◽  
Sahrul Effendy
Keyword(s):  
Alternative Energy ◽  
Bituminous Coal ◽  
Raw Materials ◽  
Calorific Value ◽  
Volatile Matter ◽  
Carbonization Temperature ◽  
Fixed Carbon ◽  
Alternative Energy Source ◽  
Tapioca Flour ◽  
Cerbera Manghas

Charcoal briquettes are smokeless fuels which are a type of solid fuel whose fly substance is made low enough so that the smoke generated on its utilization will not interfere with health. In this study charcoal briquettes were made from bintaro shell waste and betung bamboo using tapioca flour adhesives. This study aims to obtain the best quality sub-bituminous coal briquettes and coal briquettes. In this study the carbonization temperature used was 400ᵒC and the composition of raw materials for bintaro shells and betung bamboo was 50:50, the composition of raw materials for sub-bituminous coal and straw 90:10. The method used in this research is experiment or experimental method, with fuel value collection using ASTM D5865-03 standard. The results obtained from this study are for charcoal briquettes with 4000C carbonization temperature Inherent Moisture value of 1.91%, ash 2.29%, volatile matter 23.79%, fixed carbon 72.01% and calorific value 5878.7 kal / gr, and for coal briquettes obtained value Inherent Moisture 0.52%, ash 4.42%, volatile matter 17.98%, fixed carbon 77.08% and calorific value 7152.6 kal / gr. The fuel value of coal briquettes is greater than that of charcoal briquettes, but the combustion value of charcoal briquettes includes a good calorific value as an alternative energy source, and is in accordance with the SNI standard of 5000 kal / gr, even close to the Japanese standard 6000 cal / gr. Keywords: Bintaro, briquette, calorific value

Thermal and Thermo-Oxidative Degradations of Deproteinized Natural Rubber and Natural Rubber

2011 ◽  
Vol 306-307 ◽  
pp. 50-57 ◽  
Author(s):  
Can Zhong He ◽  
Zheng Peng ◽  
Jie Ping Zhong ◽  
Shuang Quan Liao ◽  
Xiao Dong She ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Natural Rubber ◽  
Oxidative Stability ◽  
Natural Rubber Latex ◽  
Oxidative Degradation ◽  
Decomposition Reaction ◽  
Nitrogen Atmosphere ◽  
Degradation Temperature ◽  
Air Atmosphere ◽  
Deproteinized Natural Rubber

Deproteinization of natural rubber was achieved in the latex stage. The structure of deproteinized natural rubber (DPNR) was characterized by fourier transform infrared spectroscopy (FTIR). The thermo degradation of DPNR was studied by thermogravimetry analysis (TG) under air atmosphere and nitrogen atmosphere. The kinetic parameters apparent activation energies (Ea) of the thermal decomposition reaction been calculated from the TG curves using the method described by Broido. And the results were compared with the thermo degradation of natural rubber (NR) under the same conditions. The effect of proteins in natural rubber latex on thermal/ thermo-oxidative stability of NR was discussed. The results show that: the absorptions of the proteins in DPNR at 1546 ㎝-1, compared to NR, become significantly weaker, nearly disappear, which indicates most of proteins has been removed from NR. The thermo degradation of DPNR in nitrogen atmosphere is a one-step reaction. The initial degradation temperature (T0) 、the maximum degradation temperature（Tp） and the final degradation temperature（Tf）as well as the Ea of DPNR are higher than those of NR, which indicates that DPNR represents a better thermal stability than NR under nitrogen atmosphere. Thermo-oxidative degradation of DPNR and NR are two-step reaction. The characteristic temperatures (T0, Tp and Tf) of DPNR are lower than those of NR. The Ea during the First Step of Thermooxidative Degradation of DPNR are also lower than those of NR. These results prove that the thermo-oxidative stability of DPNR is worse than that of NR. Protein is the key role to the thermal stability of natural rubber.

scholarly journals Impacts of Thermal Inertia Factor on Adiabatic Decomposition of 40% Mass Content DCP in Ethyl Benzene

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiaojuan Wu ◽  
Liping Chen ◽  
Guoning Rao ◽  
Wanghua Chen ◽  
Ruili Yin
Keyword(s):  
Thermal Decomposition ◽  
Thermal Inertia ◽  
Decomposition Reaction ◽  
Exothermic Peak ◽  
Ethyl Benzene ◽  
Mass Content ◽  
Experimental Conditions ◽  
Initial Decomposition Temperature ◽  
Thermal Hazards ◽  
Exponential Factor

To reduce the fire and explosion accident of dicumyl peroxide (DCP) in experiment and production, the thermal hazards of DCP and 40% mass content DCP in ethyl benzene (40% DCP) have been studied by the differential scanning calorimeter (DSC) and the accelerating rate calorimeter (ARC) in this paper. DSC experiment showed that ethyl benzene has no effect on the characteristic parameters of thermal decomposition of DCP, such as the temperature of the exothermic peak (Tpeak) and the decomposition energy (Ea), and the thermal decomposition reaction of 40% DCP followed the one-step reaction principle. ARC experiment showed that with the increase of inertia factor (Φ), the measured initial decomposition temperature (Ton) would be higher and the caculated Ea and pre-exponential factor (A) would be greater. It was also proved that after modification of Φ, TD24 was relatively consistent near Ton, but different at higher temperatures. Fisher's correction method was used to verify the necessity of consistency between experimental conditions and prediction conditions.

Thermal Behaviour of Slurry Prepared from Clermont Bituminous Coal and Oil Palm Empty Fruit Bunch Bio-Oil

2014 ◽  
Vol 906 ◽  
pp. 153-158 ◽  
Author(s):  
Hazlin Hamdan ◽  
Munawar Zaman Shahruddin ◽  
Ahmad Rafizan Mohamad Daud ◽  
Syed Shatir A. Syed-Hassan
Keyword(s):  
Power Plants ◽  
Room Temperature ◽  
Bituminous Coal ◽  
Inert Atmosphere ◽  
Empty Fruit Bunch ◽  
Blend Ratio ◽  
Thermogravimetric Analyzer ◽  
Bio Oil ◽  
Pyrolysis Behaviour ◽  
Fuel Technology

Investigation on the pyrolysis behaviour of coal-biooil slurry (CBS) fuel prepared at different ratios (100:0; 70:30; 60:40;0: 100) were conducted using a Thermogravimetric Analyzer (TGA). The selected coal sample was Clermont bituminous coal (Australia), while Empty Fruit Bunch (EFB) was used as source of bio-oil that was thermally converted by means of pyrolysis. Thermal degradation of CBS fuel was performed in an inert atmosphere (50mL/min nitrogen) under non-isothermal conditions from room temperature to 1000°C at heating rate of 10°C/min. The proportions of CBS fuel at 70:30 and 60:40 blends were observed to have influenced the fuel properties of the slurry. The addition of bio-oil will shift the temperature region towards early devolatilization. Meanwhile, the thermal profiles of the blends, showed potential trends that followed the characteristics of an ideal slurry fuel where highest degradation rate was found at the blend ratio of 60:40 biooil/coal. These findings can be useful to the development of a slurry fuel technology for application in the vast existing conventional power plants.

Microwave Torrefaction of Moist Municipal Solid Waste (MSW) Pellets with the Addition of Char from Agricultural Residues

2017 ◽  
Vol 757 ◽  
pp. 156-160
Author(s):  
Prodpran Siritheerasas ◽  
Phichayanan Waiyanate ◽  
Hidetoshi Sekiguchi ◽  
Satoshi Kodama
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bituminous Coal ◽  
Volatile Matter ◽  
Agricultural Residues ◽  
Microwave Oven ◽  
Microwave Absorber ◽  
Mass Yield ◽  
Heating Value ◽  
Microwave Absorbers

An investigation of the effect of the addition of char from agricultural residues on the torrefaction of moist municipal solid waste (MSW) pellets (40 wt.% moisture) was carried out in a microwave oven (500-800 W for 4-12 minutes). Char from agricultural residues, including corncob, palm shell, straw, and bagasse, was used as the microwave absorbers to enhance the absorption of microwave irradiation. It was found that the addition of char from bagasse yielded the lowest remaining mass (or mass yield) and volatile matter (VM) content, but the highest temperature and heating value, of the torrefied MSW pellet. Moisture in the MSW pellet with or without the addition of microwave absorber was completely removed after being torrefied for 8-12 minutes. The VM contents remained in the MSW pellets with the addition of microwave absorbers were lower than that in the MSW pellet without the addition of microwave absorber. The addition of microwave absorbers led to an increase in carbon (C) content but a decrease in oxygen (O) content of the torrefied MSW pellets, compared to those of the raw MSW pellet. The heating values of the torrefied MSW pellets with the addition of microwave absorbers were equivalent to that of sub-bituminous coal, enhanced from that of the raw MSW pellet, which was lower than that of lignite.

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