Effects of Reactor Design on the Torrefaction of Biomass

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Alok Dhungana ◽  
Prabir Basu ◽  
Animesh Dutta
Keyword(s):  
Energy Density ◽  
Fluidized Beds ◽  
Process Conditions ◽  
Convective Heating ◽  
Energy Yield ◽  
Mass Yield ◽  
Rotating Drum ◽  
Volumetric Heating ◽  
Direct Heating ◽  
Common Basis

Torrefied biomass is a green alternative to coal, and thus the interest in the torrefaction process is rising fast. Different manufacturers are offering different patented designs of torrefier with data on varying operating and process conditions each claiming their superiority over others. The choice of torrefaction technology has become exceptionally difficult because of a near absence of a comparative assessment of different types of reactors on a common base. This work attempts to fill this important knowledge gap in torrefaction technology by reviewing available types of reactors, and comparing their torrefaction performance common basis and examining the commercial implication of reactor choice. After reviewing available patent and technologies offered, torrefiers are classified broadly under two generic groups: indirectly heated and directly heated. Four generic types of reactors, convective heating, fluidized bed, rotating drum and microwave reactor were studied in this research. Convective and fluidized beds have direct heating, rotating reactors has indirect heating while microwave involves a volumetric heating (a subgroup of direct heating) mechanism. A standard sample of biomass (25 mm diameter × 64 mm long poplar wood) was torrefied in each of these types of reactors under identical conditions. The mass yield, energy density and energy yield of the wood after torrefaction were measured and compared. Rotating drum achieved lowest mass yield but highest energy density. The difference between two direct heating, convective heating and fluidized beds was small. Microwave provided only localized torrefaction in this series of tests. Indirectly heated reactors might be suitable for a plant near the biomass source while directly heated plant would give better value at the user end.

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.

High energy density matter generation using a focused soft-X-ray laser for volumetric heating of thin foils

2011 ◽  
Vol 7 (1) ◽  
pp. 11-16 ◽  
Author(s):  
B. Rus ◽  
T. Mocek ◽  
M. Kozlová ◽  
J. Polan ◽  
P. Homer ◽  
...  
Keyword(s):  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Volumetric Heating ◽  
X Ray ◽  
Thin Foils ◽  
Density Matter

Thermal Pyrolysis of Polyethylene in Fluidized Beds: Review of the Influence of Process Parameters on Product Distribution

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
K. Suresh Kumar Reddy ◽  
Pravin Kannan ◽  
Ahmed Al Shoaibi ◽  
C. Srinivasakannan
Keyword(s):  
Fluidized Bed ◽  
Process Parameters ◽  
Fluidized Beds ◽  
Pyrolysis Temperature ◽  
Liquid Product ◽  
Product Distribution ◽  
Major Influence ◽  
Process Conditions ◽  
Influence Of Process Parameters ◽  
Thermal Pyrolysis

The present work is an attempt to compile and analyze the most recent literature pertaining to thermal pyrolysis of plastic waste using fluidized bed reactors. The review is short owing to the small number of work reported in the open literature in particular to the fluidized beds. Although works on pyrolysis are reported in fixed beds, autoclaves, and fluidized beds, vast majority of them address to the utilization of fluidized bed due to their advantages and large scale adaptability. The pyrolysis temperature and the residence time are reported to have major influence on the product distribution, with the increase in pyrolysis temperature favoring gas production, with significant reduction in the wax and oil. The pyrolysis gas generally contains H2, CO, CO2, CH4, C2H4, C2H6 while liquid product comprises benzene, toluene, xylene, styrene, light oil, heavy oil, and gasoline with the variations depending on process conditions. The effects of other process parameters, namely fuel feed rate, fuel composition, and fluidizing medium have been reviewed and presented.

scholarly journals Experimental Study on Hydrothermal Carbonization of Lignocellulosic Biomass with Magnesium Chloride for Solid Fuel Production

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 444 ◽  
Author(s):  
Samuel Carrasco ◽  
Javier Silva ◽  
Ernesto Pino-Cortés ◽  
Jaime Gómez ◽  
Fidel Vallejo ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Solid Fuel ◽  
Magnesium Chloride ◽  
Calorific Value ◽  
Hydrothermal Carbonization ◽  
Volatile Matter ◽  
Matter Content ◽  
Operating Conditions ◽  
Energy Yield ◽  
Mass Yield

The effect of magnesium chloride as an additive of hydrothermal carbonization (HTC) of lignocellulosic biomass (Pinus radiata sawdust) was studied. The HTC tests were carried out at fixed conditions of temperature and residence time of 220 °C and 1 h, respectively, and varying the dose of magnesium chloride in the range 0.0–1.0 g MgCl2/g biomass. The carbonized product (hydrochar) was tested in order to determine its calorific value (HHV) while using PARR 6100 calorimeter, mass yield by gravimetry, elemental analysis using a LECO TruSpec elemental analyzer, volatile matter content, and ash content were obtained by standardized procedures using suitable ovens for it. The results show that using a dose of 0.75 g MgCl2/g biomass results in an impact on the mass yield that was almost equal to change operating conditions from 220 to 270 °C and from 0.5 to 1 h, without additive. Likewise, the calorific value increases by 33% for this additive dose, resulting in an energy yield of 68%, thus generating a solid fuel of prominent characteristics.

Cold-specific feeding response of rats to cold exposure and energy density of body weight change

1981 ◽  
Vol 51 (2) ◽  
pp. 327-334 ◽  
Author(s):  
S. D. Morrison
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Density ◽  
Heat Flow ◽  
Cold Exposure ◽  
Weight Change ◽  
Flow Model ◽  
Energy Yield ◽  
Body Weight Change ◽  
Heat Flow Model

The increased food intake of rats exposed to cold is the result of increased intake due to cold (cold-specific compartment; A) and decreased intake due to simultaneously decreased body weight (weight-specific compartment; B). The two compartments are evaluated at 5, 13, and 17 degrees C. B is evaluated as the food intake of theoretical, isogravimetric control (identical to cold-exposed rats with respect to body weight and rate of change of body weight and identical to nonexposed rats in all other respects) that takes into account both the change in energy expenditure due to decreased body weight and the energy yield from tissue catabolism represented by change of body weight. A is the observed food intake minus B. A theoretical heat-flow model, in which expected changes in heat flow during cold exposure drive food intake to maintain or restore preexposure body weight status, corroborated the partition derived from experimental data. However, both the experimental results and the heat-flow model imply that the energy density of body weight change is negatively correlated with rate of body weight change. The energy density of weight change is high with high rates of weight loss and low with high rats of weight gain.

scholarly journals Improvement of energy density and energy yield of oil palm biomass by torrefaction in combustion gas

2018 ◽  
Vol 458 ◽  
pp. 012061 ◽  
Author(s):  
Y Uemura ◽  
V Sellappah ◽  
T H Trinh ◽  
M Komiyama ◽  
S Hassan ◽  
...  
Keyword(s):  
Energy Density ◽  
Oil Palm ◽  
Energy Yield ◽  
Combustion Gas ◽  
Oil Palm Biomass

The Staged Thermal Conversion of Sewage Sludge in the Presence of Oxygen

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Mateusz Wnukowski ◽  
Krystian Krochmalny ◽  
Mateusz Kowal ◽  
Marcin Baranowski ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Sewage Sludge ◽  
Thermal Processing ◽  
Thermal Conversion ◽  
Single Step ◽  
Energy Yield ◽  
Mass Yield ◽  
Optimal Conditions ◽  
Kinetics Of ◽  
By Products

This study compares a staged thermal processing of the sewage sludge, with single step, integrated thermal processing. The aim of this study is to find the optimal conditions for drying and subsequently for carbonization/torrefaction of sewage sludge, regarding the energy consumption. This study presents the results of the drying tests performed at laboratory scale convective dryer for different parameters of drying agent (air). The tests were focused on finding and developing a method of drying that allows to minimize the energy consumption. Subsequently, both dry and vapothermal torrefaction was performed in the presence of oxygen. The kinetics of drying, using low quality heat as well as the properties of products and by-products of torrefaction in both regimes were determined. The process was characterized by mass yield and energy yield in both of the cases. There has been only scarce amount of literature studies published on the torrefaction of sewage sludge so far, without a detailed study of the composition of the torgas and tars of such origin. Performed study enables a comparison of two distinct scenarios of the processing, i.e., drying followed by dry torrefaction with a single stage of vapothermal torrefaction.

scholarly journals INVESTIGATION OF THE INFLUENCE OF MICROWAVE RADIATION ON THE PROPERTIES OF GRANULAR HEAT INSULATION MATERIALS BASED ON LIQUID GLASS

2021 ◽  
pp. 6-16
Author(s):  
Tatyana Rymar
Keyword(s):  
Microwave Radiation ◽  
Liquid Glass ◽  
Structural Changes ◽  
Glass Composition ◽  
Thermal Action ◽  
Convective Heating ◽  
Energy Costs ◽  
Chemical Methods ◽  
Volumetric Heating ◽  
Insulation Materials

The main methods of improving the performance of granular thermal insulationmaterials based on liquid glass are chemical methods of their modification, which are based onchanging their structure through the use of special ingredients. At the same time, there is a need to introduce often a large number of components and individual technological operations, which is notalways technological. One of the promising methods of changing the physical state of substancesunder the action of an electromagnetic field is non-thermal treatment of microwave radiation. Theadvantages of using microwave radiation in comparison with the generally accepted methods ofmodification of materials are the transformation of their structure without significant changes in thetechnological process and the need to use additional components. Due to volumetric heating and themechanism of non-thermal action of microwave radiation on processing objects the duration of theirheating considerably decreases. When microwave heating of a liquid glass composition part of theenergy of electromagnetic radiation is converted into heat, which contributes to the intense swellingof the material, and the other part is aimed at structural changes in the material, which improve itsproperties due to the non-thermal effect of microwave radiation. Studies show that the best set ofperformance properties have granular materials obtained under the action of microwave radiationat a power of 650 W, which corresponds to a temperature of 110-120 0C. The required duration ofsuch heat treatment is 6-7 minutes. The closest to them in terms of coefficient of swelling are materialsobtained by convective heating at a temperature of 200 0C for 1 hour, but their physical andmechanical properties are much lower. Thus, it can be noted that the use of microwave radiationallows to obtain granular thermal insulation materials with a better set of performance properties atlower energy costs for their production.

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