Thermodynamic analysis of ethanol/water system with the stoichiometric method

Mas, V.; Kipreos, R.; Amadeo, Norma; Laborde, Miguel

doi:10.1016/j.ijhydene.2005.04.004

Cited by 129 publications

(86 citation statements)

References 19 publications

(49 reference statements)

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“…As shown by equilibrium calculations (for example, [43,44], for two different methodologies) a sufficient loading of a catalyst with the correct selectivity towards the reforming can eliminate any byproduct (except methane) when working at the proper temperature.…”

Section: Esr: Conversion Rates and Steady Statesmentioning

confidence: 99%

Process Simulation for the Design and Scale Up of Heterogeneous Catalytic Process: Kinetic Modelling Issues

et al. 2017

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Abstract:Process simulation represents an important tool for plant design and optimization, either applied to well established or to newly developed processes. Suitable thermodynamic packages should be selected in order to properly describe the behavior of reactors and unit operations and to precisely define phase equilibria. Moreover, a detailed and representative kinetic scheme should be available to predict correctly the dependence of the process on its main variables. This review points out some models and methods for kinetic analysis specifically applied to the simulation of catalytic processes, as a basis for process design and optimization. Attention is paid also to microkinetic modelling and to the methods based on first principles, to elucidate mechanisms and independently calculate thermodynamic and kinetic parameters. Different case studies support the discussion. At first, we have selected two basic examples from the industrial chemistry practice, e.g., ammonia and methanol synthesis, which may be described through a relatively simple reaction pathway and the relative available kinetic scheme. Then, a more complex reaction network is deeply discussed to define the conversion of bioethanol into syngas/hydrogen or into building blocks, such as ethylene. In this case, lumped kinetic schemes completely fail the description of process behavior. Thus, in this case, more detailed-e.g., microkinetic-schemes should be available to implement into the simulator. However, the correct definition of all the kinetic data when complex microkinetic mechanisms are used, often leads to unreliable, highly correlated parameters. In such cases, greater effort to independently estimate some relevant kinetic/thermodynamic data through Density Functional Theory (DFT)/ab initio methods may be helpful to improve process description.

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Section: Esr: Conversion Rates and Steady Statesmentioning

confidence: 99%

Process Simulation for the Design and Scale Up of Heterogeneous Catalytic Process: Kinetic Modelling Issues

et al. 2017

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“…Thermodynamic analysis shows that coke production, with graphite structure, is unfavorable when the water to ethanol ratio is equal to three, at temperatures exceeding 227e277 C [35]. In the present work, however, coke formation may be related to the production of a disordered carbonaceous structure instead of graphite one.…”

Section: Catalysts Evaluationmentioning

confidence: 49%

“…In the present work, however, coke formation may be related to the production of a disordered carbonaceous structure instead of graphite one. Moreover, the thermodynamic analysis cannot predict the composition inside reactor when the system is far from equilibrium [35]. We can see that the lowest amount of coke was deposited on the RA and RM samples, which showed the same amount, the RAM sample showed higher amounts.…”

Section: Catalysts Evaluationmentioning

confidence: 88%

Ethanol steam reforming over rhodium and cobalt-based catalysts: Effect of the support

Moura

Souza

Bellido

et al. 2012

International Journal of Hydrogen Energy

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“…While the steam reforming of ethanol provides high hydrogen yields, it is a highly endothermic reaction and thus high operation temperatures are necessary. However, many other reactions can occur simultaneously with hydrogen production reactions [55,56]. Some of these result in the formation of undesirable products.…”

Section: Reaction Schemementioning

confidence: 99%

Hydrogen Production by the Steam Reforming of Bio-Ethanol over Nickel-Based Catalysts for Fuel Cell Applications

Chen¹,

Xu²

2017

IJSGE

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Abstract:The bio-ethanol steam reforming over nickel-based catalysts when the temperature is within the range of 700 to 800 K is studied for fuel cell applications. The effect of operating conditions such as the temperature, space time, water-to-ethanol molar ratio, and oxygen-to-ethanol molar ratio on the product distribution is evaluated. The water-gas shift reaction is examined in the reforming process. Adjusting feed ratios to favor carbon removal from the surface is discussed in detail. It is shown that a nickel-supported-on-alumina catalyst completely converts bio-ethanol and high hydrogen yields are obtained. High temperatures and water-to-ethanol ratios can promote hydrogen production. There is no evidence that the water-gas shift reaction occurs over nickel-based catalysts. Carbon formation can be minimized by using high water-to-ethanol ratios. The presence of oxygen in the feed plays a favorable effect on the carbon deposition, but the carbon monoxide production is not reduced. There are several reaction pathways that could occur in the bio-ethanol steam reforming process, and the catalyst produces ethylene and acetaldehyde as intermediate products. The region of carbon formation depends on the temperature as well as the water-to-ethanol and oxygen-to-ethanol molar ratios. Finally, an overall reaction scheme as a function of temperature is proposed. The best catalysts appear to be those that are sufficiently basic to inhibit the dehydration of ethanol to ethylene, which subsequently polymerizes and causes coke formation.

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Thermodynamic analysis of ethanol/water system with the stoichiometric method

Cited by 129 publications

References 19 publications

Process Simulation for the Design and Scale Up of Heterogeneous Catalytic Process: Kinetic Modelling Issues

Process Simulation for the Design and Scale Up of Heterogeneous Catalytic Process: Kinetic Modelling Issues

Ethanol steam reforming over rhodium and cobalt-based catalysts: Effect of the support

Hydrogen Production by the Steam Reforming of Bio-Ethanol over Nickel-Based Catalysts for Fuel Cell Applications

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