scholarly journals Methodologies for the Design of Solar Receiver/Reactors for Thermochemical Hydrogen Production

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 308
Author(s):  
M.A. Murmura ◽  
M.C. Annesini
Keyword(s):  
Hydrogen Production ◽  
Solar Energy ◽  
Fossil Fuels ◽  
Optimization Procedure ◽  
Particle Morphology ◽  
Operating Conditions ◽  
Solid Particles ◽  
Technical Requirements ◽  
Solar Reactors ◽  
Solar Receiver

Thermochemical hydrogen production is of great interest due to the potential for significantly reducing the dependence on fossil fuels as energy carriers. In a solar plant, the solar receiver is the unit in which solar energy is absorbed by a fluid and/or solid particles and converted into thermal energy. When the solar energy is used to drive a reaction, the receiver is also a reactor. The wide variety of thermochemical processes, and therefore of operating conditions, along with the technical requirements of coupling the receiver with the concentrating system have led to the development of numerous reactor configurations. The scope of this work is to identify general guidelines for the design of solar reactors/receivers. To do so, an overview is initially presented of solar receiver/reactor designs proposed in the literature for different applications. The main challenges of modeling these systems are then outlined. Finally, selected examples are discussed in greater detail to highlight the methodology through which the design of solar reactors can be optimized. It is found that the parameters most commonly employed to describe the performance of such a reactor are (i) energy conversion efficiency, (ii) energy losses associated with process irreversibilities, and (iii) thermo-mechanical stresses. The general choice of reactor design depends mainly on the type of reaction. The optimization procedure can then be carried out by acting on (i) the receiver shape and dimensions, (ii) the mode of reactant feed, and (iii) the particle morphology, in the case of solid reactants.

Application of Recuperative Gas Cycles with a Bypass Heat Generator to Solar Energy Power Plants

1980 ◽  
Vol 102 (1) ◽  
pp. 153-159
Author(s):  
Z. P. Tilliette ◽  
B. Pierre
Keyword(s):  
Solar Energy ◽  
Heat Source ◽  
Power Plants ◽  
Energy Conversion Efficiency ◽  
Operating Conditions ◽  
Heat Generator ◽  
Combined Cycles ◽  
Flexible Plant ◽  
Favorable Conditions ◽  
Solar Receiver

Gas cycles are being studied for solar energy power plants on account of the attractive prospects they offer for an efficient heat source utilization. By using a particular arrangement applicable to open or closed recuperative gas cycles, consisting of a heat generator partly bypassing the low pressure side of the recuperator, further improvements can be effected in gas turbine systems. They result in favorable conditions for power and high temperature heat cogeneration, for combined gas and steam cycles, and for flexible plant operation. Specific aspects of solar energy are investigated. They mainly concern variations in operating conditions, energy storage, energy conversion efficiency and combined cycles. Applications are made to open and closed cycle power plants. As the combination of a solar receiver with a fossil-fired auxiliary heat source is considered, fossil-fired power plants with an auxiliary solar heating are examined.

Computational Fluid Dynamics Modeling of Gas-Particle Flow Within a Solid-Particle Solar Receiver

2006 ◽  
Vol 129 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Huajun Chen ◽  
Yitung Chen ◽  
Hsuan-Tsung Hsieh ◽  
Nathan Siegel
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Solar Radiation ◽  
Solid Particle ◽  
Operating Conditions ◽  
Solid Particles ◽  
Particle Flow ◽  
Outlet Temperature ◽  
Solar Receiver

A detailed three-dimensional computational fluid dynamics (CFD) analysis on gas-particle flow and heat transfer inside a solid-particle solar receiver, which utilizes free-falling particles for direct absorption of concentrated solar radiation, is presented. The two-way coupled Euler-Lagrange method is implemented and includes the exchange of heat and momentum between the gas phase and solid particles. A two-band discrete ordinate method is included to investigate radiation heat transfer within the particle cloud and between the cloud and the internal surfaces of the receiver. The direct illumination energy source that results from incident solar radiation was predicted by a solar load model using a solar ray-tracing algorithm. Two kinds of solid-particle receivers, each having a different exit condition for the solid particles, are modeled to evaluate the thermal performance of the receiver. Parametric studies, where the particle size and mass flow rate are varied, are made to determine the optimal operating conditions. The results also include detailed information for the gas velocity, temperature, particle solid volume fraction, particle outlet temperature, and cavity efficiency.

CFD Modeling of Gas Particle Flow Within a Solid Particle Solar Receiver

Solar Energy ◽  
2006 ◽  
Author(s):  
Huajun Chen ◽  
Yitung Chen ◽  
Hsuan-Tsung Hsieh ◽  
Nathan Siegel
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Solid Particle ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Operating Conditions ◽  
Solid Particles ◽  
Particle Flow ◽  
Cfd Modeling ◽  
Solar Receiver

A detailed three dimensional computational fluid dynamics (CFD) analysis on gas-particle flow and heat transfer inside a solid particle solar receiver, which utilizes free-falling particles for direct absorption of concentrated solar radiation, is presented. The two-way coupled Euler-Lagrange method is implemented and includes the exchange of heat and momentum between the gas phase and solid particles. A two band discrete ordinate method is included to investigate radiation heat transfer within the particle cloud and between the cloud and the internal surfaces of the receiver. The direct illumination energy source that results from incident solar radiation was predicted by a solar load model using a solar ray tracing algorithm. Two kinds of solid particle receivers, each having a different exit condition for the solid particles, are modeled to evaluate the thermal performance of the receiver. Parametric studies, where the particle size and mass flow rate are varied, are made to determine the optimal operating conditions. The results also include detailed information for the particle and gas velocity, temperature, particle solid volume fraction, and cavity efficiency.

Enhancing Hydrogen Production by Photobiocatalysis through Rhodopseudomonas palustris Coupled with Conjugated Polymers

2021 ◽  
Author(s):  
Zijuan Wang ◽  
Dong Gao ◽  
Hao Geng ◽  
Chengfen Xing
Keyword(s):  
Hydrogen Production ◽  
Solar Energy ◽  
Conjugated Polymers ◽  
Fossil Fuels ◽  
Rhodopseudomonas Palustris ◽  
Water Soluble ◽  
Promising Alternative ◽  
Water Soluble P ◽  
Hybrid Complex ◽  
Soluble P

Utilizing solar energy for hydrogen production by combining light-activated materials and biocatalyst has become a promising alternative to fossil fuels. Herein, a feasible and simple bio-hybrid complex based on water-soluble...

Solar Hydrogen Production by a Two-Step Cycle Based on Mixed Iron Oxides

Solar Energy ◽  
2005 ◽  
Author(s):  
Martin Roeb ◽  
Christian Sattler ◽  
Ruth Klu¨ser ◽  
Nathalie Monnerie ◽  
Lamark de Oliveira ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Solar Energy ◽  
Metal Oxide ◽  
Iron Oxides ◽  
Operating Conditions ◽  
Solar Furnace ◽  
Solar Irradiation ◽  
Redox Systems ◽  
Solar Hydrogen ◽  
Solar Hydrogen Production

A very promising method for the conversion and storage of solar energy into a fuel is the dissociation of water to oxygen and hydrogen, carried out via a two-step process using metal oxide redox systems such as mixed iron oxides, coated upon multi-channeled honeycomb ceramic supports capable of absorbing solar irradiation, in a configuration similar to that encountered in automobile exhaust catalytic converters. With this configuration, the whole process can be carried out in a single solar energy converter, the process temperature can be significantly lowered compared to other thermo-chemical cycles and the re-combination of oxygen and hydrogen is prevented by fixing the oxygen in the metal oxide. For the realization of the integrated concept, research work proceeded in three parallel directions: synthesis of active redox systems, manufacture of ceramic honeycomb supports and manufacture, testing and optimization of operating conditions of a thermochemical solar receiver-reactor. The receiver-reactor has been developed and installed in the solar furnace in Cologne, Germany. It was proven that solar hydrogen production is feasible by this process demonstrating that multi cycling of the process was possible in principle.

Solar Hydrogen Production by a Two-Step Cycle Based on Mixed Iron Oxides

2005 ◽  
Vol 128 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Martin Roeb ◽  
Christian Sattler ◽  
Ruth Klüser ◽  
Nathalie Monnerie ◽  
Lamark de Oliveira ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Solar Energy ◽  
Metal Oxide ◽  
Iron Oxides ◽  
Operating Conditions ◽  
Solar Furnace ◽  
Solar Irradiation ◽  
Redox Systems ◽  
Solar Hydrogen ◽  
Solar Hydrogen Production

A promising method for the conversion and storage of solar energy into hydrogen is the dissociation of water into oxygen and hydrogen, carried out via a two-step process using metal oxide redox systems such as mixed iron oxides, coated upon multi-channeled honeycomb ceramic supports capable of absorbing solar irradiation, in a configuration similar to that encountered in automobile exhaust catalytic converters. With this configuration, the whole process can be carried out in a single solar energy converter, the process temperature can be significantly lowered compared to other thermo-chemical cycles and the recombination of oxygen and hydrogen is prevented by fixing the oxygen in the metal oxide. For the realization of the integrated concept, research work proceeded in three parallel directions: synthesis of active redox systems, manufacture of ceramic honeycomb supports and manufacture, testing and optimization of operating conditions of a thermochemical solar receiver-reactor. The receiver-reactor has been developed and installed in the solar furnace in Cologne, Germany. It was proven that solar hydrogen production is feasible by this process demonstrating that multicycling of the process was possible in principle.

scholarly journals TiO2 Nanotubes Architectures for Solar Energy Conversion

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 931
Author(s):  
Yin Xu ◽  
Giovanni Zangari
Keyword(s):  
Solar Energy ◽  
Tio2 Nanotubes ◽  
Fossil Fuels ◽  
Photovoltaic Effect ◽  
Electric Energy ◽  
Chemical Species ◽  
Electrochemical Anodization ◽  
Science And Engineering ◽  
Electric Energy Storage ◽  
The Usa

Electromagnetic light from the Sun is the largest source, and the cleanest energy available to us; extensive efforts have been dedicated to developing science and engineering solutions in order to avoid the use of fossil fuels. Solar energy transforms photons into electricity via the photovoltaic effect, generating about 20 GW of energy in the USA in 2020, sufficient to power about 17 million households. However, sunlight is erratic, and technologies to store electric energy storage are unwieldy and relatively expensive. A better solution to store energy and to deliver this energy on demand is storage in chemical bonds: synthesizing fuels such as H2, methane, ethanol, and other chemical species. In this review paper we focus on titania (TiO2) nanotubes grown through electrochemical anodization and various modifications made to them to enhance conversion efficiency; these semiconductors will be used to implement the synthesis of H2 through water splitting. This document reviews selected research efforts on TiO2 that are ongoing in our group in the context of the current efforts worldwide. In addition, this manuscript is enriched by discussing the latest novelties in this field.

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