scholarly journals Experimental Evaluation of Indirect Heating Tubular Reactors for Solar Methane Pyrolysis

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Sylvain Rodat ◽  
Stéphane Abanades ◽  
Gilles Flamant
Keyword(s):  
Carbon Black ◽  
Plasma Heating ◽  
Solar Furnace ◽  
Solar Irradiation ◽  
Hydrogen Yield ◽  
Heating Source ◽  
Solar Reactor ◽  
Production Of Hydrogen ◽  
Carbon Black Production ◽  
Indirect Heating

Solar thermal pyrolysis of natural gas is studied for the co-production of hydrogen, a promising energy carrier, and Carbon Black, a high-value nano-material, with the bonus of zero CO2 emissions. A 10 kW multi-tubular solar reactor (SR10) based on the indirect heating concept was designed, constructed and tested. It is composed of an insulated cubic cavity receiver (20 cm side) that absorbs concentrated solar irradiation through a quartz window by a 9 cm-diameter aperture. The solar concentrating system is the 1 MW solar furnace of CNRS-PROMES laboratory. An argon-methane mixture flows inside four graphite tubular reaction zones each composed of two concentric tubes that are settled vertically inside the cavity. Experimental runs mainly showed the key influence of the residence time and temperature on the reaction extent. Since SR10 design presented a weak recovery of carbon black in the filter, a single tube configuration was tested with an external plasma heating source. Complete methane conversion and hydrogen yield beyond 80% were achieved at 2073K. Hydrogen and carbon mass balances showed that C2H2 intermediates affect drastically the carbon black production yield: about half of the initial carbon content in the CH4 was found as C2H2 in the outlet gas. Nevertheless, the carbon black recovery in the filtering device was improved with this new configuration. Data are extrapolated to predict the possible hydrogen and carbon production for a future 50 kW solar reactor. The expected production was estimated to be about 2.47 Nm3/h H2 and 386 g/h carbon black for 1.47 Nm3/h of CH4 injected.

scholarly journals Methane Decarbonization in Indirect Heating Solar Reactors of 20 and 50 kW for a CO2-Free Production of Hydrogen and Carbon Black

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Sylvain Rodat ◽  
Stéphane Abanades ◽  
Gilles Flamant
Keyword(s):  
Carbon Black ◽  
Large Scale ◽  
Process Analysis ◽  
Solar Irradiation ◽  
Flow Sheet ◽  
Experimental Conditions ◽  
Solar Reactor ◽  
Production Of Hydrogen ◽  
Solar Reactors ◽  
Indirect Heating

Solar methane decarbonization is an attractive pathway for a transition toward an hydrogen-based economy. In the frame of the European SOLHYCARB project, it was proposed to investigate this solar process extensively. At CNRS-PROMES, two indirect heating solar reactors (20 and 50 kW) were designed, built, and tested for methane decarbonization. They consist of graphite cavity-type receivers approaching the blackbody behavior. The CH4 dissociation reaction was carried out in tubular sections inserted in the solar absorber receiving concentrated solar irradiation. The 20 kW solar reactor (SR20) was especially suitable to study the chemical reaction and methane conversion performances depending on the experimental conditions (mainly temperature and residence time). The 50 kW solar reactor (SR50) was operated to produce significant amounts of carbon black for determining its properties and quality in the various possible commercial applications. The main encountered problem was the particle evacuation. Solutions were proposed for large-scale industrial applications. A process analysis was achieved for a 14.6 MW solar chemical plant on the basis of a process flow-sheet. A production of 436 kg/h of hydrogen and 1300 kg/h of carbon black could be obtained for 1737 kg/h of methane consumed, with an hydrogen cost competitive to conventional methane reforming. This paper summarizes the main results and conclusions of the project.

Coupled Concentrating Optics, Heat Transfer, and Thermochemical Modeling of a 100-kWth High-Temperature Solar Reactor for the Thermal Dissociation of ZnO

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
W. Villasmil ◽  
T. Cooper ◽  
E. Koepf ◽  
A. Meier ◽  
A. Steinfeld
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Energy Conversion ◽  
Solar Flux ◽  
Solar Furnace ◽  
Solar Irradiation ◽  
Radiation Boundary Condition ◽  
Solar Reactor ◽  
Concentrated Solar Energy ◽  
Conversion Efficiencies

This work reports a numerical investigation of the transient operation of a 100-kWth solar reactor for performing the high-temperature step of the Zn/ZnO thermochemical cycle. This two-step redox cycle comprises (1) the endothermal dissociation of ZnO to Zn and O2 above 2000 K using concentrated solar energy, and (2) the subsequent oxidation of Zn with H2O/CO2 to produce H2/CO. The performance of the 100-kWth solar reactor is investigated using a dynamic numerical model consisting of two coupled submodels. The first is a Monte Carlo (MC) ray-tracing model applied to compute the spatial distribution maps of incident solar flux absorbed on the reactor surfaces when subjected to concentrated solar irradiation delivered by the PROMES-CNRS MegaWatt Solar Furnace (MWSF). The second is a heat transfer and thermochemical model that uses the computed maps of absorbed solar flux as radiation boundary condition to simulate the coupled processes of chemical reaction and heat transfer by radiation, convection, and conduction. Experimental validation of the solar reactor model is accomplished by comparing solar radiative power input, temperatures, and ZnO dissociation rates with measured data acquired with the 100-kWth solar reactor at the MWSF. Experimentally obtained solar-to-chemical energy conversion efficiencies are reported and the various energy flows are quantified. The model shows the prominent influence of reaction kinetics on the attainable energy conversion efficiencies, revealing the potential of achieving ηsolar-to-chemical = 16% provided the mass transport limitations on the ZnO reaction interface were overcome.

scholarly journals A pilot-scale solar reactor for the production of hydrogen and carbon black from methane splitting

2010 ◽  
Vol 35 (15) ◽  
pp. 7748-7758 ◽  
Author(s):  
Sylvain Rodat ◽  
Stéphane Abanades ◽  
Jean-Louis Sans ◽  
Gilles Flamant
Keyword(s):  
Carbon Black ◽  
Pilot Scale ◽  
Solar Reactor ◽  
Production Of Hydrogen

Phase changes in the lining of reactors used for carbon black production

Refractories ◽  
1965 ◽  
Vol 6 (9-10) ◽  
pp. 452-457 ◽  
Author(s):  
Z. D. Zhukova ◽  
N. V. Pitak ◽  
V. G. �ntin
Keyword(s):  
Carbon Black ◽  
Phase Changes ◽  
Carbon Black Production

4643880 Apparatus and process for carbon black production

Carbon ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. II
Author(s):  
William R King ◽  
C Jack Hart
Keyword(s):  
Carbon Black ◽  
Carbon Black Production

scholarly journals Analysis of the Plasma Recycling Process of Radioactive Waste

2019 ◽  
pp. 23-29
Author(s):  
M. Semerak ◽  
S. Lys ◽  
T. Kovalenko
Keyword(s):  
Radioactive Waste ◽  
Silicon Oxide ◽  
Raw Materials ◽  
Shaft Furnace ◽  
Plasma Heating ◽  
Plasma Processing ◽  
Radioactive Wastes ◽  
Heating Source ◽  
Long Term Storage ◽  
Plasmochemical Reactor

The possibility of the plasma processing of low-level or intermediatelevel radioactive wastes in the reactor equipped with arc plasmatrons is shown. The reactor design for the plasma processing of the radioactive wastes that allows promoting the efficiency of the plasma processing of the radioactive wastes (RAW) by the increasing of the speed and the intensity of the plasma pyrolysis is proposed. The various methods for RAW preparation, dosage and supply into the plasmochemical reactor have been investigated. The waste which is supplied to the reactor can be in various aggregate states (solid, liquid or gaseous) depending on which different kinds of preparation, dosage, and supply of RAW materials to the plasmochemical reactor are used. The solid waste must be ground for increasing of the phase separation surface. The degree of grinding of the wastes depends on their further reprocessing. The reactor allows processing of the mixed-type radioactive waste, which includes both combustible and non-combustible components. The wastes can be packed or ground up. The selected technological regimes should provide temperature from 1500 °C in the melting chamber to 250 °C in the upper part in the pyrogas exit zone to prevent the flow-out of volatile compounds of a series of radionuclides and heavy metals from the furnace and to process the waste and merge slag melt without adding of fluxes. The fused slag is a basaltiform monolith, where the content of aluminum oxide reaches 28%; silicon oxide up to 56%; sodium oxide from 2.5 to 11 %. The resulting radioactive slag is extremely resistant to the chemical influence. The pyrogas produced in the shaft furnace will have a heating value of about 5 MJ/nm3. This allows, after initial heating by plasmatron, maintaining the required temperature in the combustion chamber due to the heat released during combustion of the pyrogas, when the plasma heating source is switched off, and burning the resin and soot effectively. It is proved that the plasma technology for RAW reprocessing allows a significant reduction in waste volumes and waste placement for long-term storage with the most efficient use of storage facilities.

Numerical Analysis of Carbon Black Production from Sub‐Quality Natural Gas

2008 ◽  
Author(s):  
M. Moghiman ◽  
M. Javadi ◽  
M. H. Ghodsirad ◽  
N. Hosseini ◽  
M. Soleimani
Keyword(s):  
Numerical Analysis ◽  
Natural Gas ◽  
Carbon Black ◽  
Carbon Black Production

Bio-electrochemical production of hydrogen and electricity from organic waste

2021 ◽  
Author(s):  
Giorgia De Gioannis ◽  
Alessandro Dell'Era ◽  
Aldo Muntoni ◽  
Mauro Pasquali ◽  
Alessandra Polettini ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Electron Flow ◽  
Dark Fermentation ◽  
Electrochemical Process ◽  
Integrated System ◽  
Galvanic Cell ◽  
Hydrogen Yield ◽  
Cell Coupling ◽  
Production Of Hydrogen ◽  
Acid Metabolites

Abstract This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the biological process and is mediated by the electron flow from the galvanic cell, coupling biochemical and electrochemical hydrogen production. Accordingly, the galvanic compartment also generates electricity. Four different experimental setups were designed to provide a preliminary assessment of the integrated bio-electrochemical process and identify the optimal configuration for further tests. Subsequently, dark fermentation of cheese whey was implemented both in a stand-alone biochemical reactor and in the integrated bio-electrochemical process. The integrated system achieved a hydrogen yield in the range 75.5 – 78.8 N LH2/kg TOC, showing a 3 times improvement over the biochemical process.

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