Transportation and Storage

Berkowitz, N.

doi:10.1016/b978-0-12-091950-5.50015-8

Cited by 6 publications

(2 citation statements)

References 7 publications

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“…The interaction between water vapor and coal also generates a significant amount of heat when water condenses on coal. These two processes must be taken into account in any attempt to describe the self-heating of the coal stockpile as was stressed by Carras and Young and many other researchers. − If the basic equations, mass and energy balance equations, with the rate processes including the heat generation rates are formulated and the initial and boundary conditions are described definitely, it is possible in principle to simulate the spontaneous heating by solving the basic equations with the initial and boundary conditions. In an actual coal stockpile, however, it is almost impossible to definitely know the initial and boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Spontaneous Heating of a Small Fixed Bed of Dried Coal Exposed to a Flowing Wet Air Stream

Miura

2019

Energy Fuels

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First, less than 30 g of brown coal packed in a sphere stainless net and placed in an air naturally circulating temperature-programmed oven was found to start spontaneous combustion from the center of the coal sphere when the oven temperature was raised to 135 °C. This was because the heat generation rate by the oxidation of coal was larger than the rate of heat dissipation rate by natural convection at 135 °C. Next, to clarify the mechanism by which coal is heated to 135 °C, the temperature increase of less than 10 g of the fixed bed of dried brown coal was measured by contacting the coal with flowing dry air or wet air at 50, 70, 95, and 107 °C. It was found that the maximum temperature increase in the dry air was almost null at 70 °C and only 5 °C or so even at 107 °C. On the other hand, the maximum temperature increases were respectively 10, 25, 46, and 40 °C at 50, 70, 95, and 107 °C in the wet air, suggesting that the adsorption of water vapor plays a crucial role in increasing the coal temperature high enough for the spontaneous combustion to start. A simple simulation program was developed for expressing the temperature change observed by the above fixed bed experiment by formulating the mass and enthalpy balance equations with the separately measured heat generation rate by the coal–oxygen interaction at 50–150 °C and the adsorption isotherm and the heat of adsorption of water vapor on coal at 70 °C. The simulation program well expressed the temperature change for the experiments performed at 70 °C in both the wet air and the dry air, indicating that the spontaneous heating of coal is brought about by the coupled effect of the adsorption of water vapor and the coal oxygen interaction. In addition, the simulation showed how the spontaneous combustion of coal starts in the wet air.

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Section: Introductionmentioning

confidence: 99%

Simulation of Spontaneous Heating of a Small Fixed Bed of Dried Coal Exposed to a Flowing Wet Air Stream

Miura

2019

Energy Fuels

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“…Berkowitz and Schein, in 1951, reported that a more general trigger of sustained, self-accelerating coal oxidation has been seen in heat releases that accompany wetting of partly dry coal. This mechanism is afforded by repeated observation that stockpiled coal most often tends to heat up when exposed to rain after a period of dry, sunny weather.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Water Vapor from Ambient Atmosphere onto Coal Fines Leading to Spontaneous Heating of Coal Stockpile

Miura

2015

Energy Fuels

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Low rank coals are susceptible to spontaneous combustion, because oxidation rate of low rank coals are higher than that of high rank coals. Even low rank coals, however, must be heated over a critical temperature before spontaneous combustion starts. This work assumed that rapid spontaneous combustion of coal in stockpile will start from the heat up of coal fines on the surface of the stockpile by the heat supplied from the sun and moist air. Then direct measurement of possible temperature increase by the adsorption of water vapor on coal from ambient atmosphere was undertaken by using three kinds of brown coals/lignites and a bituminous coal. When about 100 mg of each brown coal pre-dried at 80 °C and cooled to 28 °C were exposed to an ambient and stationary atmosphere of 28 °C with 67−77% relative humidity, the coal temperatures increased up to 40−43 °C in a minute or so. When the brown coals pre-dried and cooled to 38 °C were exposed to a stagnant saturated air at 38 °C, the coal temperatures increased up to over 60 °C in a minute or so. This was found to occur by rapid adsorption of water vapor from the ambient atmosphere onto the coal. Next, a simple model based on mass and enthalpy balances was successfully formulated to simulate the water adsorption and temperature change. The model simulation then clarified that the amount of heat generated by the adsorption of water vapor are much larger than the heat generated by initial coal oxidation and that most of heat generated is transferred to the surrounding to be utilized to heat up the surroundings. Thus, the important role of the adsorption of water vapor from the ambient atmosphere on the spontaneous heating of coal fines in stockpile was clarified.

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Modelling and simulation of a multi-commodity pipeline network

Noguera

Leirens

2010

2010 Ieee Andescon

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Pipeline networks play an important role in the petroleum industry, because these systems provide a connection between ports, oil fields and refineries, as well as consumer markets. The refined products (commodities) such as gasoline, jet fuel, diesel, etc. are transported through a unique pipe. This is a way to avoid the additional cost of several pipes dedicated to specific products. This mode of transportation presents issues like product contamination, which increases the operation costs. Hence, the contaminated portion needs to be processed again or poured at low concentrations with other products. The issue of modeling and simulation of multi-commodity pipelines takes into account the pressure, velocity and including the fluid density. Then, in this paper a dynamic model of multicommodity pipeline network is developed considering pipes interconnected with pumps. Moreover a mixture model is added to the network. This model allows to predict the contaminated interface in each pipe section.

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Transportation and Storage

Cited by 6 publications

References 7 publications

Simulation of Spontaneous Heating of a Small Fixed Bed of Dried Coal Exposed to a Flowing Wet Air Stream

Simulation of Spontaneous Heating of a Small Fixed Bed of Dried Coal Exposed to a Flowing Wet Air Stream

Adsorption of Water Vapor from Ambient Atmosphere onto Coal Fines Leading to Spontaneous Heating of Coal Stockpile

Modelling and simulation of a multi-commodity pipeline network

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