Experimental Setup of a Laser Diagnostics System for a High-Temperature Solar Receiver/Reactor

1994 ◽  
Vol 116 (4) ◽  
pp. 206-211 ◽  
Author(s):  
A. Steinfeld ◽  
R. Bombach ◽  
P. Haueter ◽  
B. Hemmerling ◽  
W. Kreutner ◽  
...  
Keyword(s):  
High Temperature ◽  
Laser Diagnostics ◽  
Cone Angle ◽  
Experimental Setup ◽  
Gas Temperature ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Diagnostics System ◽  
Solar Receiver ◽  
Anti Stokes

A solar receiver/reactor has been designed specifically to study high-temperature gas phase chemical reactions using a laser based metrology. It is a cavity-type receiver, lined with stabilized ZrO2, and operated at temperatures up to 2000 K. The gas temperature is measured in situ using the coherent anti-Stokes Raman spectroscopy (CARS) of N2. Optical access for the CARS measurement is accomplished via two side windows, each subtending a 118-mrad cone angle at the center of the cavity, providing enough clearance for the input laser beams and the output signal carrying the temperature information. Two endothermic processes were used for the initial evaluation of this method: the NH3 dissociation into N2 and H2, and the CO2-reforming of CH4 into synthesis gas. The process flow was directly exposed to high solar fluxes in addition to infrared radiation emitted by the hot reactor walls. The laser-based metrology performed satisfactorily in spite of the presence of the intense radiation field. This paper describes in detail the technical aspects of the experimental setup, presents examples of spectra and temperature measurements, and discusses practical problems encountered during experimentation.

Chemical Kinetics Simulation of High Temperature Hydrocarbons Reforming in a Solar Reactor

Solar Energy ◽  
2003 ◽  
Author(s):  
Rachamim Rubin ◽  
Jacob Karni ◽  
Jacob Yeheskel
Keyword(s):  
High Temperature ◽  
Experimental Work ◽  
Model Development ◽  
Chemical Kinetic ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Hydrocarbon Reforming ◽  
Kinetics Simulation ◽  
Definition Of ◽  
Shift Reaction

This study is aimed at developing a simulation model of a solar Volumetric reactor for hydrocarbon reforming, operating at high temperature and pressure. It will then be used to optimize the reactor design and analyze its performance. The model development utilizes previous and on-going experimental work on Volumetric receiver and catalyst development. The reaction’s kinetics are computed, using the CHEMKIN II simulation package. The chemical kinetic modeling of the relevant C-H-O system is based on: (i) Definition of the relevant computation domain and parameters: temperature, pressure, reactant compositions, residence time, and catalyst load, (ii) Utilizing laboratory measurements at 700–1400K and 1–4 bar. to quantify the kinetic parameters for both, H2O, and CO2 reforming of CH4 and for the Reverse Water Shift reaction. Calculated and measured data are compared for three representative cases, showing a good agreement. The results indicate that the Arrhenius method can be a viable and practical way to predict the behavior of steam and CO2 reforming over a range of temperatures and pressures. Furthermore, it is shown that the present approach can provide a method for estimating the desirable dimensions of the reactor for reforming of CH4. Additional, on-going computational and experimental work, which would provide a more accurate simulation, can easily be implemented using the present numerical model.

Chemical Kinetics Simulation of High Temperature Hydrocarbons Reforming in a Solar Reactor

2004 ◽  
Vol 126 (3) ◽  
pp. 858-866 ◽  
Author(s):  
Rachamim Rubin ◽  
Jacob Karni ◽  
Jacob Yeheskel
Keyword(s):  
High Temperature ◽  
Experimental Work ◽  
Model Development ◽  
Chemical Kinetic ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Hydrocarbon Reforming ◽  
Kinetics Simulation ◽  
Definition Of ◽  
Shift Reaction

This study is aimed at developing a simulation model of a solar volumetric reactor for hydrocarbon reforming, operating at high temperature and pressure. It will then be used to optimize the reactor design and analyze its performance. The model development utilizes previous and on-going experimental work on volumetric receiver and catalyst development. The reaction’s kinetics are computed, using the CHEMKIN II simulation package. The chemical kinetic modeling of the relevant C-H-O system is based on: (i) Definition of the relevant computation domain and parameters: temperature, pressure, reactant compositions, residence time, and catalyst load, (ii) Utilizing laboratory measurements at 700–1400 K and 1–4 bar. to quantify the kinetic parameters for both, H2O, and CO2 reforming of CH4 and for the Reverse Water Shift reaction. Calculated and measured data are compared for three representative cases, showing a good agreement. The results indicate that the Arrhenius method can be a viable and practical way to predict the behavior of steam and CO2 reforming over a range of temperatures and pressures. Furthermore, it is shown that the present approach can provide a method for estimating the desirable dimensions of the reactor for reforming of CH4. Additional, on-going computational and experimental work, which would provide a more accurate simulation, can easily be implemented using the present numerical model.

CO2 Reforming of CH4 on Mesoporous Alumina-Supported Cobalt Catalyst: Optimization of Lanthana Promoter Loading

2021 ◽  
Author(s):  
Ngoc Thang Tran ◽  
P. Senthil Kumar ◽  
Quyet Van Le ◽  
Nguyen Van Cuong ◽  
Pham T. T. Phuong ◽  
...  
Keyword(s):  
Cobalt Catalyst ◽  
Mesoporous Alumina ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4

Experimental investigation of wall heat transfer due to spray combustion in a high-pressure/high-temperature vessel

2021 ◽  
pp. 146808742110072
Author(s):  
Karri Keskinen ◽  
Walter Vera-Tudela ◽  
Yuri M Wright ◽  
Konstantinos Boulouchos
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
Transfer Problem ◽  
Wall Heat Transfer ◽  
Gas Temperature ◽  
Reference Case ◽  
High Pressure High Temperature

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting to the surrounding gas temperature) have been pinpointed as a promising mitigative solution. In this study, experiments are carried out in a high-pressure/high-temperature vessel to (a) characterise the wall heat transfer process ensuing from wall impingement of a combusting fuel spray, and (b) evaluate insulative improvements provided by a coating that promotes thermal swing. The baseline experimental condition resembles that of Spray A from the Engine Combustion Network, while additional variations are generated by modifying the ambient temperature as well as the injection pressure and duration. Wall heat transfer and wall temperature measurements are time-resolved and accompanied by concurrent high-speed imaging of natural luminosity. An investigation with an uncoated wall is carried out with several sensor locations around the stagnation point, elucidating sensor-to-sensor variability and setup symmetry. Surface heat flux follows three phases: (i) an initial peak, (ii) a slightly lower plateau dependent on the injection duration, and (iii) a slow decline. In addition to the uncoated reference case, the investigation involves a coating made of porous zirconia, an established thermal swing material. With a coated setup, the projection of surface quantities (heat flux and temperature) from the immersed measurement location requires additional numerical analysis of conjugate heat transfer. Starting from the traces measured beneath the coating, the surface quantities are obtained by solving a one-dimensional inverse heat transfer problem. The present measurements are complemented by CFD simulations supplemented with recent rough-wall models. The surface roughness of the coated specimen is indicated to have a significant impact on the wall heat flux, offsetting the expected benefit from the thermal swing material.

Promotional effect of La2O3 and CeO2 on Ni/γ-Al2O3 catalysts for CO2 reforming of CH4

2010 ◽  
Vol 385 (1-2) ◽  
pp. 92-100 ◽  
Author(s):  
Ruiqin Yang ◽  
Chuang Xing ◽  
Chengxue Lv ◽  
Lei Shi ◽  
Noritatsu Tsubaki
Keyword(s):  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Promotional Effect

scholarly journals Dynamic Oxygen on Surface: Catalytic Intermediate and Coking Barrier in the Modeled CO2 Reforming of CH4 on Ni (111)

ACS Catalysis ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 4330-4339 ◽  
Author(s):  
Kaidi Yuan ◽  
Jian-Qiang Zhong ◽  
Xiong Zhou ◽  
Leilei Xu ◽  
Susanna L. Bergman ◽  
...  
Keyword(s):  
Co2 Reforming ◽  
Co2 Reforming Of Ch4
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