Combustion of torrefied pellets of furniture work dusts as blends with lignite

2020 ◽  
pp. 1-21
Author(s):  
Melek Yilgin ◽  
Bedriye Hos ◽  
Dursun Pehlivan
Keyword(s):  
Natural Convection ◽  
Initial Temperature ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Moisture Contents ◽  
Vertical Furnace ◽  
Carbon Combustion ◽  
Ignition Times

Abstract In this study, torrefaction of pellets formed from furniture work dusts collected as a part of space cleaning actions in the industry have been examined. Burning behaviour of torrefied dusts and lignite blends was studied. Torrefaction experiments were done under nitrogen atmosphere for one hour at temperatures of 220, 260 and 300°C which corresponded to light, mild and severe torrefaction, respectively. Combustion of blend pellets prepared by adding lignite in specific ratios to powders of torrefied pellets was carried out at 700°C initial temperature using a vertical furnace system through which air was flowing in natural convection. Ignition times of blend pellets were affected from volatile matter and moisture contents. Volatile matter combustion rates were lower than those of raw waste and accordingly, combustion times were higher. However, no relation between volatile matter combustion rates and times was observed. Blending raw or torrefied furniture work dusts with lignite have significantly influenced volatile matter and carbon combustion periods. There was no relation between carbon combustion rates and times. It was concluded that blend pellets of mild or severe torrefaction products of furniture work dusts and lignite behaved similarly to lignite during combustion.

scholarly journals Study on Pyrolysis Characteristics of Coal and Combustion Gas Release in Inert Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Liang Dong ◽  
Ziming Wang ◽  
Yadong Zhang ◽  
Junyu Lu ◽  
Enhui Zhou ◽  
...  
Keyword(s):  
Mass Loss ◽  
Ftir Spectroscopy ◽  
Minimum Weight ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Gas Analysis ◽  
Gas Release ◽  
Combustion Gas ◽  
Pyrolysis Reaction ◽  
Pyrolysis Characteristics

In this study, thermogravimetric analysis (TGA) coupled with Fourier transform infrared (FTIR) spectroscopy was used to heat the coal samples of six different coalification degrees from room temperature to 1000°C at 20°C·min−1 under nitrogen atmosphere. The influence of coal degree and pyrolysis temperature on the content of pyrolysis products of coal was analyzed by the TG/DTG curve. FTIR spectroscopy was used to obtain the IR spectra of generated gases and study their variation at different temperatures in the process of coal heating without oxygen, and the gas release during pyrolysis was discussed. The results showed that the pyrolysis reaction initiated at 400°C and ended at 800°C. The maximum mass loss occurred in the temperature range of 480 to 500°C. The values of maximum and minimum weight loss rates were 32.72 and 18.89%, respectively. The mass loss during the pyrolysis process corresponded well with the volatile matter contained in the sample. Permanent gas analysis and IR spectrum analysis indicated that when the temperature was 600°C, the peak value of methane (CH4) appeared at 3016 wave, indicating the generation of CH4 at this time. When the temperature reached 700°C, the peak area of 2360 wave increased, all coal samples began to release carbon dioxide (CO2), release rate of CH4 gas decreased, and yield of CO2 was maximized. At 800°C, all peaks of 3160 wave disappeared, indicating that there was no unreacted short-chain release at this temperature. At the same time, the pyrolysis reaction tended to remove the excess hydrogen-oxygen conjugates in the carbon structure and release them in the form of water vapor.

Entropy Generation in Natural Convection of Water Near Its Density Maximum in a Square Cavity

2004 ◽  
Author(s):  
You-Rong Li ◽  
Nu-Bo Deng ◽  
Shuang-Ying Wu ◽  
Lan Peng ◽  
Dan-Ling Zeng
Keyword(s):  
Natural Convection ◽  
Entropy Generation ◽  
Initial Temperature ◽  
Temperature Fields ◽  
Local Entropy ◽  
Balance Equations ◽  
Square Cavity ◽  
Density Maximum ◽  
Thermal Entropy ◽  
Local Entropy Generation

This paper is focused on the entropy generation due to heat transfer and viscous flow in natural convection of water near its density maximum in a square cavity. The present hydrodynamic and temperature fields are obtained by solving numerically the mass, momentum and energy balance equations, using the finite difference method. Local entropy generation distributions are obtained based on the resulting velocity and temperature fields by solving the entropy generation equation. The effect of the Grashof numbers on the total entropy generation is studied. Local entropy generation distribution was found to be dependent on the Grashof number and the dimensionless initial temperature. The results also show that thermal entropy generation is relatively dominant over viscous entropy generation.

Analyses of Coal and Sewage Sludge Co-Combustion Using Coats-Redfern Model

2012 ◽  
Vol 518-523 ◽  
pp. 3271-3274
Author(s):  
Huan Li ◽  
Yang Yang Li ◽  
Yi Ying Jin
Keyword(s):  
Activation Energy ◽  
Ignition Temperature ◽  
Burning Velocity ◽  
Fire Behavior ◽  
Volatile Matter ◽  
Water Evaporation ◽  
Fixed Carbon ◽  
Carbon Combustion ◽  
Blend Fuel ◽  
Dried Sludge

The co-combustibility of coal and sludge was investigated with thermogravimetric analysis. The results show that the burning process of sludge can be divided into three phases: water evaporation, volatile matter volatilization and combustion, fixed carbon combustion and burning out. The ignition temperature of sludge is only 260 degree centigrade at the beginning of volatile matter combustion. The addition of wet sludge or dried sludge will reduce the burning velocity of coal, and also decrease the ignition temperature. However the blend of coal and sludge has not an obvious stage of the volatile matter volatilization and combustion. The activation energy of the sludge is lower than that of the coal. The addition of wet sludge or dried sludge will decrease the activation energy of the blend fuel, and improve the fire behavior. On the whole, the sludge addition has little influence on the combustion of the coal when the addition ratio is lower than 10%.

scholarly journals Experimental and Theoretical Fuel Property Comparison of Four Different Waste Biomass with A Commercial Counterpart

2021 ◽  
Author(s):  
Mustafa Kaan Baltacıoğlu ◽  
Mustafa Tunahan Başar ◽  
Hüseyin Turan Arat ◽  
Yasin Erdoğan
Keyword(s):  
Calorific Value ◽  
Orange Peel ◽  
Volatile Matter ◽  
Waste Biomass ◽  
Heating Value ◽  
Moisture Contents ◽  
Accredited Laboratory ◽  
Pomegranate Seed ◽  
Pomegranate Seeds ◽  
Pellet Form

Abstract This study focuses on determining the fuel properties of apple pulp, pomegranate seeds, pomegranate peel and orange peel wastes and converting them into pellet fuel. Within the scope of the study, the organic wastes were dried, ruined into small pieces and then pressed to take the pellet form. Moisture content, ash content, volatile matter determination, fixed carbon content, total sulfur content, hydrogen content, lower heating value and higher heating value were analyzed as solid fuel characterization process. Experiments were carried out in an internationally accredited laboratory in accordance with ASTM and TS EN ISO/IEC 17025 Standards. Considering the results, it was determined that the pellet obtained from fully dry state pomegranate seed had a calorific value of 4244 kcal/kg, whereas the commercial pellet was 4759 kcal/kg under the same conditions. On the other hand, the moisture contents of the commercial pellet and pomegranate seed sample were 5.42% and 1.83%, respectively. The drying process was one of the costliest stages of pellet production. The low moisture contents can reduce the production cost and shorten the time.

Numerical Simulation of Heat Transfer Characteristics of Melting Process of Paraffin Heat Storage Ball

2013 ◽  
Vol 291-294 ◽  
pp. 1690-1695
Author(s):  
Shu Hui Xu ◽  
Guo Qiang Yang
Keyword(s):  
Natural Convection ◽  
Liquid Phase ◽  
Initial Temperature ◽  
Heat Storage ◽  
Time History ◽  
Melting Process ◽  
Heat Transfer Characteristics ◽  
Average Temperature ◽  
History Of ◽  
Solid Liquid

In this paper, a paraffin heat storage ball whose diameter is 100mm is the research object. Two mathematical models of paraffin melting process are established respectively when the natural convection of liquid phase of paraffin is considered and ignored. The melting process of paraffin heat storage ball which initial temperature is 290K is simulated by using the solidification/melting model of FLUENT. Through analyzing the temperature distribution of the ball and proportion of solid-liquid phase in the ball in the melting process at a certain time, studying the time history of the proportion of liquid phase in the ball and the time history of the average temperature of the paraffin, we can find that the natural convection of liquid phase of paraffin can not be ignored in the melting process of paraffin heat storage ball whose diameter is 100mm.

Production of Gaseous Fuel from High-Ash Tailings by Pyrolysis

2012 ◽  
Vol 550-553 ◽  
pp. 458-463
Author(s):  
Hai Bing Liu ◽  
Xing Min Fu ◽  
Tao Zhu ◽  
Shu Cheng Liu ◽  
Xin Qian Shu
Keyword(s):  
Heating Rate ◽  
Heating Temperature ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Total Volatile ◽  
Gaseous Products ◽  
Pyrolysis Characteristics ◽  
Pyrolysis Unit ◽  
Higher Temperature ◽  
Evolution Behavior

he characteristics of pyrolysis gaseous are conducted out in a laboratory pyrolysis unit with a 30 g charge at vary finial temperature .Based on isothermal thermogravimetric analysis (TGA) was also applied to study the effects of heating rate on the pyrolysis characteristics of tailings in nitrogen atmosphere. The TG/DTG results show that the heating rate increases, the temperature of volatile matter initiation increases, the total volatile matter evolved decreases and the DTG peak shifts toward higher temperature range. The experiment indicated that with increasing heating temperature in rank, total gas, caloric value, H2 and CO yields gradually increases and CH4 and CO2 first increase and then decrease for all samples. The evolution behavior of gaseous products during primary devolatilisation (400–550°C)and secondary devolatilisation (700–850°C) was also discussed. The results showed that the gas yield was up to 4.306L and the largest capacity hydrogen production was 1.72L in the 950°C and by the charge (30 g ).

scholarly journals Thermal decomposition of torrefied and carbonized briquettes of residues from coffee grain processing

2013 ◽  
Vol 37 (3) ◽  
pp. 221-228 ◽  
Author(s):  
Thiago de Paula Protásio ◽  
Isabel Cristina Nogueira Alves de Melo ◽  
Mario Guimarães Junior ◽  
Rafael Farinassi Mendes ◽  
Paulo Fernando Trugilho
Keyword(s):  
Thermal Decomposition ◽  
Fossil Fuels ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Matter Content ◽  
Gravimetric Analysis ◽  
Heating Rates ◽  
Fixed Carbon ◽  
Grain Processing ◽  
Eucalyptus Sawdust

The use of biomass has been recognized as a potential renewable energy and an alternative substitute that contributes to the decrease of fossil fuels consumption. Therefore, this research aimed to analyze the thermal behavior of briquettes made of residues from coffee grain processing in different conditions: in natura, torrefied and carbonized. Eucalyptus sawdust was used for comparison. The briquettes were carbonized considering final temperature of 450° C (kept for 30 min). The briquettes torrefaction was performed in an electric oven (muffle) using two heating rates until 250° C (kept 60 min). The thermal-gravimetric analysis was made in nitrogen atmosphere until the temperature of 600° C. The contents of fixed carbon and volatile matter of the fuels were determined. The carbonized briquette of residues from coffee grain processing presented higher stability and low thermal decomposition. It was observed a low influence of torrefaction heating rate under thermal properties of briquettes, and fixed carbon and volatile matter content. Regarding the raw biomass, lower total mass loss was observed for the residues from coffee grain processing when compared to Eucalyptus sawdust. The carbonized and torrefied briquettes presented higher hydrophobicity than raw briquettes.

Evidence of a Convective Instability Allowing Warm Water to Freeze in Less Time Than Cold Water

1996 ◽  
Vol 118 (1) ◽  
pp. 65-72 ◽  
Author(s):  
P. K. Maciejewski
Keyword(s):  
Natural Convection ◽  
Flow Field ◽  
Initial Temperature ◽  
Cold Water ◽  
Warm Water ◽  
Cooling Process ◽  
Convective Cooling ◽  
Convective Motions ◽  
Different Levels ◽  
Field Inversion

This experimental study explores the possibility that warm water may freeze in less time than cold water due to natural convection alone, i.e., in the absence of significant cooling by evaporation. This possibility is rooted in the following two hypotheses: (1) The Rayleigh number associated with a sample of warm water may exceed a critical value above which the convective motions within the water sample may become turbulent and enhance the rate of convective cooling, and (2) the inversion of the flow field that is expected to occur in the vicinity of maximum density, i.e., at 4°C, will occur at different points in the cooling process for identical samples of water at different levels of initial temperature and result in an enhanced rate of convective cooling after the flow field inversion for those cases at higher levels of initial temperature that enter the flow field inversion with higher kinetic energy. The results of this study establish that, under certain circumstances, a sample of water that is initially warm will freeze in less time than an identical sample of water that is initially cold due to natural convection alone.

Fast Pyrolysis of Biomass With Activated Alumina

2011 ◽  
Author(s):  
Funda Ates¸
Keyword(s):  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Activated Alumina ◽  
Pyrolysis Oils ◽  
Pyrolysis Of Biomass

In this study, corncob was chosen as a biomass sample and the pyrolysis of this sample was carried out with or without catalyst at different conditions in a well-swept fixed-bed reactor. In the experimental studies, firstly the raw material was analysed for its moisture, ash, volatile matter and fixed carbon. Then, experiments were conducted with a heating rate of 700 °C/min, mean particle size and between 300–800 °C pyrolysis temperatures with or without catalyst. The catalytic experiments involved a dry mixing of the catalyst with the biomass using an in bed-mode in the nitrogen atmosphere. In the experimental studies, influence of catalyst and temperature on the corncob products was investigated. According to the experimental results; maximum bio-oil yield was obtained as 36.1% and 34.8% with or without catalyst at a pyrolysis temperature of 500°C, respectively. The use of catalyst showed its cracking effect at higher temperatures and the gas yield increased above pyrolysis temperature of 500 °C. Pyrolysis oils were examined by using elemental analysis and GC/MS. According to all results; the use of catalyst can be suggested in the pyrolysis to obtain both good quality fuels and valuable chemicals.

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