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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"devolatilization"”.
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Devolatilization of pulverized coal at high temperatures.
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
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Rapid devolatilization and hydrogasification of pulverized coal,
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1974.
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A COMPUTATIONAL STUDY OF DEVOLATILIZATION AND KINETICS IN ENTRAINED FLOW COAL GASIFICATION
… years related to turbulence, gaseous combustion, devolatilization and char reactions. The CFD model of gasification must be valid for a range of operating conditions, reactor designs and feedstock compositions. Although tremendous strides have been made in every aspect of gasification modeling, …
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A Mathematical Model for the Devolatilization of EPDM Rubber in a Series of Steam Stripping Vessels
A steady-state mathematical model for the stripping section of an industrial EPDM rubber production process was developed for a three-tank process, and two four-tank processes. The experiments that were conducted to determine model parameters such as equivalent radius for EPDM particles, as well as …
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Optimization of Great Plains Coal Gasification Using Aspen/SP
… capacity assumes that the energy associated with devolatilization is thermally neutral. However, pressure differential scanning calorimeter tests of five North Dakota lignite coal samples indicate this energy is exothermic. </p><p>In this study, some significant model improvements have been made. …
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Multi-scale chemistry modeling of the thermochemical conversion of biomass in a fluidized bed gasifier
… First, the particle scale conversion, devolatilization, is considered and a model is developed capturing the interactions of external and internal heat transfer with primary devolatilization chemistry. It is shown that the particle diameter, via internal heat transfer, plays a …
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Computational Scheme Guided Design of a Hybrid Mild Gasifier
… this study are to (a) incorporate a fixed rate devolatilization model into the existing 2D multiphase reaction model, (b) expand the 2D model to 3D and (c) utilize the improved model to investigate the mild-gasification process and guide modification of the mild-gasifier design. The …
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Field emission measurements of solid fuel stoves in Yunnan, China
… Real-time data show two distinct burn phases: a devolatilization phase after fuel addition with high PM2.5 emissions, and a solid-fuel combustion phase with low PM2.5 emissions. The average emission factors depend on the relative contributions of these phases, which are affected by the services …
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Comprehensive Black Liquor Droplet Combustion Studies
… of volatiles, droplet swelling, and enthalpy of devolatilization were proved to be significant. Intermediate-sized particle (ISP) formation was investigated with a suspended-droplet experimental technique. The images indicate that a small amount of particles are ejected during drying. …
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Development of an Advanced Stem Heating Model
… the processes of bark swelling, desiccation, and devolatilization are treated in an approximate fashion. Simulation with a surface flux boundary condition requires that these phenomena be accounted for. Previous models have used temperature-time boundary conditions, which prevents them from being …
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Simulation of Combustion and Thermal-flow Inside a Petroleum Coke Rotary Calcining Kiln
… a uniform distribution of moisture evaporation, devolatilization, and coke fines entrainment rate with a conjugate radiation-convection-conduction calculation. The results show the 3-D behavior of the flow, the reaction inside the kiln, heat transfer and the effect of the tertiary air on coke bed …
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Dispersion and dissolution kinetics of API particles in pharmaceutical hot melt extrusion
… melting, dispersive and distributive mixing, devolatilization and stripping, and finally pressurization and pumping. However, for pharmaceutical HME, the dissolution of the API (Active Pharmaceutical Ingredient) is an additional and very important elementary step, along with the melting of the …
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Coal gasification for fuel synthesis: Multiphysics modeling and new concepts
… particle-phase reactions, moisture drying, devolatilization, porous structure evolution, convective and radiative heat transfer, as well as full coupling between the two phases at various scales for mass, species, and energy exchange. Numerical simulations were conducted to understand the …
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Biomass characterization and reduced order modeling of mixed-feedstock gasification
… on the state of the art in biomass pyrolysis/devolatilization modeling. An existing coal Entrained Flow Gasification (EFG) Reduced Order Model (ROM) was expanded to more accurately simulate the gasification of a mixed feedstock of biomass and coal. The GE 2700tpd gasifier was used because it …
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Investigation of high-temperature and high-pressure steam gasification kinetics of a coal-derived char surrogate
… material proceeds in two primary steps: the devolatilization of the feedstock followed by the gasification reactions of the remaining carbon (char). As the gasification reactions are significantly slower than combustion reactions or the devolatilization step, these reactions are rate …
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Investigation of high-temperature and high-pressure steam gasification kinetics of a coal-derived char surrogate
… material proceeds in two primary steps: the devolatilization of the feedstock followed by the gasification reactions of the remaining carbon (char). As the gasification reactions are significantly slower than combustion reactions or the devolatilization step, these reactions are rate …
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Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics
… The char that is left in the reactor after devolatilization can be oxidized in order to maximize the amount of biomass carbon that is converted to gaseous carbon and generate heat to drive endothermic gasification reactions. This paper examines the rate of each of the three processes that …
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Dynamic reduced order modeling of entrained flow gasifiers
… recirculation, particle properties, drying and devolatilization, chemical kinetics, fluid dynamics, heat transfer, pollutant formation, slag behavior and syngas cooling. The ROM employs a reactor network model (RNM) that approximates complex fluid mixing and recirculation using a series of …
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Fluids in Planetary Systems
… of fluid inclusions, leading to shock devolatilization of target rocks. In addition, the absence of fluid inclusions in planetary materials does not preclude the presence of fluids on the meteorite's parent body. Thermodynamic modeling of aqueous alteration of basalt under Mars-relevant …
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