scholarly journals Thermal Degradation of Cassava Rhizome in Thermosyphon-Fixed Bed Torrefaction Reactor

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 267 ◽  
Author(s):  
Nitipong Soponpongpipat ◽  
Suwat Nanetoe ◽  
Paisan Comsawang
Keyword(s):  
Temperature Distribution ◽  
Fixed Bed ◽  
Decomposition Reaction ◽  
Fixed Bed Reactor ◽  
Energy Yield ◽  
Mass Yield ◽  
The Difference ◽  
Laboratory Reactor ◽  
Decomposition Behavior ◽  
Purge Gas

A thermosyphon-fixed bed reactor was designed and constructed to investigate the temperature distribution of the cassava rhizome and its decomposition behavior. To study the properties of torrefied char obtained from this reactor, cassava rhizome was torrefied in five different configurations, including the thermosyphon-fixed bed reactor, a laboratory reactor in compact bulk arrangement with N2 as the purge gas and without any purge gas, and another one in a hollow bulk arrangement with and without purge gas. It was found that the use of thermosyphons with a fixed bed reactor improved the uniform temperature distribution. The average heating rate to the cassava rhizome bed was 1.40 °C/min, which was 2.59 times higher than that of the fixed bed reactor without thermosyphons. Compared to the other configurations, this reactor gave the highest higher heating value (HHV) and the lowest mass yield of 23.97 MJ/kg and 47.84%, respectively. The water vapor produced in this reactor played an autocatalyst role in the decomposition reaction. Finally, the thermosyphon-fixed bed reactor gave an energy yield in the range of 70.43% to 86.68%. The plot of the HHV ratio–mass yield diagram indicated the difference of torrefied char obtained from different reactors. The thermosyphon-fixed bed reactor produced torrefied biomass with the highest HHV ratio compared to that of other reactors at the same energy yield.

scholarly journals Thermal and Torrefaction Characteristics of a Small-Scale Rotating Drum Reactor

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 489
Author(s):  
Nitipong Soponpongpipat ◽  
Suwat Nanetoe ◽  
Paisan Comsawang
Keyword(s):  
Heat Loss ◽  
Small Scale ◽  
Reactor Wall ◽  
Energy Yield ◽  
Exhaust Gas ◽  
Mass Yield ◽  
Rotating Drum ◽  
Reactor Types ◽  
Purge Gas ◽  
Rotating Drum Reactor

The small-scale rotating drum reactor (SS-RDR) was designed and constructed without using purge gas for the purpose of household application. The thermal and torrefaction characteristics of SS-RDR were studied and compared with other reactor types. It was found that the heat loss at the reactor wall and heat loss from exhaust gas of the SS-RDR were in the range of 6.3–12.4% and 27.9–42.8%, respectively. The increase of flue gas temperature resulted in the decrease of heat loss at the reactor wall and the increase of heat loss from exhaust gas. The heating rate of the SS-RDR was in the range of 7.3–21.4 °C/min. The higher heating value (HHV) ratio, mass yield, and energy yield ofthe SS-RDR were in the range of 1.2–1.6, 35.0–81.0%, and 56.2–96.5%, respectively. A comparison of torrefaction characteristics of various reactor types on HHV ratio-mass yield-iso-energy yield diagram indicated that the torrefaction characteristics of the SS-RDR were better than that of the rotating drum reactor with purge gas.

Fuel Gases from Gasification Process of Glass Fiber/Epoxy Composite Waste

2011 ◽  
Vol 695 ◽  
pp. 5-8
Author(s):  
Kaew Saetiaw ◽  
Duangduen Atong ◽  
Viboon Sricharoenchaikul ◽  
Duangdao Aht-Ong
Keyword(s):  
Glass Fiber ◽  
Epoxy Composite ◽  
Fixed Bed ◽  
Nitrogen Atmosphere ◽  
Fixed Bed Reactor ◽  
Gasification Process ◽  
Glass Fiber Reinforced ◽  
Decomposition Behavior ◽  
Thermosetting Composite ◽  
Gas Conversion

Currently solid wastes generated from manufacturing process of thermosetting composite have caused environmental problems because they are non biodegradable product and cannot be recycled or remolded due to chemically crosslinked. Thus, the aim of this research is to convert glass fiber reinforced epoxy composite waste to fuel gases by gasification process. The composite waste was first grounded and its thermal decomposition behavior was then investigated using isothermal thermogravimetric analysis (TGA) from an ambient to 900°C at heating rate of 10°C/min under nitrogen atmosphere. The results showed that major decomposition temperatures of the epoxy matrix were ranging from 300 to 450°C. The composite sample was then mixed with two different catalysts, olivine (LiFePO4) or 10%NiAl2O3in order to study the effect of catalyst on gas conversion efficiency before it was gasified in a fixed bed reactor at final temperature of 500, 600, 700, and 800°C under nitrogen mixed with air at total flow rate of 200 mL/min. Gasification process indicated that solid residues were mainly brittle black containing residual glass fiber. The significant increasing of carbon monoxide and carbon dioxide conversion was achieved from sample mixed with olivine catalyst at gasification temperature of 700°C, when compared with result without catalyst at baseline conversion of 500°C as. Therefore, it can be expected that gasification process is a promising method to deal with epoxy composite for producing renewable energy.

scholarly journals Pretreatment of Coconut Shell by Torrefaction for Pyrolysis Conversion

2021 ◽  
Vol 920 (1) ◽  
pp. 012002
Author(s):  
R Ahmad ◽  
S M Ahmahdi ◽  
A R Mohamed ◽  
C Z A Abidin ◽  
N N Kasim
Keyword(s):  
Reaction Time ◽  
Fixed Bed ◽  
Pyrolysis Product ◽  
Calorific Value ◽  
Product Yield ◽  
Thermal Conversion ◽  
Fixed Bed Reactor ◽  
Coconut Shell ◽  
Energy Yield ◽  
Ultimate Analysis

Abstract This study describes the influence of torrefied coconut shell (CS) as solid fuel on pyrolysis product yield. The CS were torrefied and then pyrolysed in a fixed-bed reactor at different temperature and reaction time. The raw and torrefied CS were analysed for mass and energy yield, proximate analysis and ultimate analysis. The pyrolysis products yield were compared between raw CS and torrefied CS. The results showed that the properties of torrefied CS in terms of proximate and ultimate analysis were enhanced than raw CS. The calorific value for torrefied CS increased 17.17 MJ/kg to 22.25 MJ/kg. The optimum condition obtained for torrefaction pretreatment was at 275 °C and reaction time of 60 min. The highest bio-oil yield of 45% from pyrolysis process was at temperature and reaction time of 500 °C and 6 min, respectively. Thus, these results indicate torrefied CS was a suitable fuel feedstock to conduct in thermal conversion such as pyrolysis.

Hydrogen Production via Methane Decomposition Using Ni and Ni-Cu Catalysts Supported on MgO, Al2O3 and MgAl2O4

2010 ◽  
Vol 1279 ◽  
Author(s):  
José F. Pola ◽  
Miguel A. Valenzuela ◽  
Iván A. Córdova ◽  
J. A. Wang
Keyword(s):  
Bimetallic Catalysts ◽  
Fixed Bed ◽  
Decomposition Reaction ◽  
Methane Decomposition ◽  
Fixed Bed Reactor ◽  
Magnesium Aluminate ◽  
Alloy Formation ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support

AbstractNi (10%) and Ni-Cu (50 and 25%, respectively) catalysts supported on alumina, magnesia and magnesium aluminate were synthesized. The characterization was carried out by X-ray diffraction, nitrogen physisorption, temperature programmed-reduction, Raman spectroscopy and SEM. The catalysts were tested in the methane decomposition reaction using a tubular fixed bed reactor operated in the range of 500-580°C under atmospheric pressure. A higher activity was observed with the bimetallic catalysts supported on alumina and magnesium aluminate. These results were explained in terms of Ni-Cu alloy formation and weak metal-support interaction. In the case of monometallic catalysts, a strong metal-support interaction was detected, which revealed the lowest activity and stability compared with the bimetallic catalysts. The formed carbon was a combination of amorphous and graphite.

Respiration rate measurement in a submerged fixed bed reactor

2003 ◽  
Vol 47 (5) ◽  
pp. 201-204 ◽  
Author(s):  
M. Carrión, ◽  
A. Asaff ◽  
F. Thalasso
Keyword(s):  
Respiration Rate ◽  
Oxygen Uptake Rate ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Rate Measurement ◽  
Air Flow Rate ◽  
Hydraulic Conditions ◽  
Novel Method ◽  
The Difference ◽  
Respiration Rate Measurement

A novel method is presented to measure the overall biofilm respiration rate in a submerged fixed bed reactor. The method, named “double gassing-out” is based on the measurement of the oxygen uptake rate under two different conditions: (i) replacing the air flow rate by nitrogen in the biological reactor, ensuring the conservation of the same hydraulic conditions and (ii) measuring the oxygen displacement rate by nitrogen in an identical reactor design with no microorganisms. The difference between these measurements gives the overall biofilm respiration rate. Results obtained in a nitrifying fixed bed reactor are presented, compared to classical techniques and discussed.

scholarly journals Combustion of Flax Shives, Beech Wood, Pure Woody Pseudo-Components and Their Chars: A Thermal and Kinetic Study

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2146 ◽  
Author(s):  
Nourelhouda Boukaous ◽  
Lokmane Abdelouahed ◽  
Mustapha Chikhi ◽  
Abdeslam-Hassen Meniai ◽  
Chetna Mohabeer ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Raw Materials ◽  
Beech Wood ◽  
Fixed Bed ◽  
Thermal Characteristics ◽  
Principal Component ◽  
Fixed Bed Reactor ◽  
Pure Cellulose ◽  
The Difference ◽  
Flax Shives

Thermogravimetric analysis was employed to investigate the combustion characteristics of flax shives, beech wood, hemicellulose, cellulose, lignin, and their chars. The chars were prepared from raw materials in a fixed-bed reactor at 850 °C. In this study, the thermal behavior based on characteristic temperatures (ignition, maximum, and final temperatures), burnout time and maximum rate was investigated. The kinetic parameters for the combustion of different materials were determined based on the Coats-Redfern approach. The results of our study revealed that the combustion of pure pseudo-components behaved differently from that of biomass. Indeed, principal component analysis showed that the thermal behavior of both biomasses was generally similar to that of pure hemicellulose. However, pure cellulose and lignin showed different behaviors compared to flax shives, beech wood, and hemicellulose. Hemicellulose and cellulose chars had almost the same behaviors, while being different from biomass and lignin chars. Despite the difference between flax shives and beech wood, they showed almost the same thermal characteristics and apparent activation energies. Also, the combustion of the hemicellulose and cellulose chars showed that they have almost the same structure. Their overall thermal and kinetic behavior remained between that of biomass and lignin.

A Novel Kinetics Study on H2O2 Decomposition inthe Propylene Epoxidation System in a Fixed-Bed Reactor

2013 ◽  
Vol 11 (1) ◽  
pp. 265-269 ◽  
Author(s):  
Lina Wang ◽  
Yaquan Wang ◽  
Guoqiang Wu ◽  
Wenping Feng ◽  
Teng Zhang ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Decomposition Reaction ◽  
Fixed Bed Reactor ◽  
Kinetics Equation ◽  
Propylene Epoxidation ◽  
H2o2 Decomposition ◽  
First Order ◽  
First Order Kinetics ◽  
Reaction Activation Energy ◽  
First Time

Abstract H2O2 decomposition in the propylene epoxidation system in a fixed-bed reactor was studied herein for the first time. The decomposition rate of H2O2 increased with increasing reaction temperature. The decomposition reaction followed the first-order kinetics equation at 30–50°C, whereas it did not follow the equation any longer at higher than 50°C. A kinetics equation for the H2O2 decomposition catalyzed by TS-1/SiO2 at 30–50°C was obtained, and the reaction activation energy Ea was calculated as 69.26 kJ/mol.

Simulation of Fixed Bed Reactor for the Dehydration Reaction from Alcohol Gas to Ethylene

2014 ◽  
Vol 910 ◽  
pp. 123-126 ◽  
Author(s):  
Ying Tao Song ◽  
Ming Yan Dang
Keyword(s):  
Temperature Distribution ◽  
Fixed Bed ◽  
Axial Direction ◽  
Fixed Bed Reactor ◽  
Outlet Temperature ◽  
Target Product ◽  
Dehydration Reaction ◽  
Gas Velocity ◽  
Reaction Characteristics ◽  
Radial Heat

A numerical model has been established and solved to describe the dehydration reaction from alcohol to ethylene. The influences of the gas velocity and the temperature of the feeding gas to the process of the reaction were discussed. The results showed that, the influence of the radial diffusion on the reaction characteristics could be ignored while the influence of radial heat conduction to the temperature distribution was significant. The temperature distribution decreased alone the axial direction at first and then increased, that is a lowest point of the temperature could be found. When the velocity of the gas slowed down or the temperature of the feeding gas increased, the conversion of the reactant and the selectivity of the target product could be improved, the distance of the lowest temperature point to the entrance got closer and the outlet temperature became higher.

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