scholarly journals Experimental carbothermal reduction of MgO at low pressure using concentrated solar energy

2018 ◽  
Vol 54 (1) ◽  
pp. 39-50 ◽  
Author(s):  
J. Puig ◽  
M. Balat-Pichelin
Keyword(s):  
Solar Energy ◽  
Carbothermal Reduction ◽  
High Yield ◽  
Concentrated Solar Energy ◽  
Initial Stage ◽  
Calculated Activation Energy ◽  
Dominant Process ◽  
Short Time ◽  
Boundary Reaction ◽  
Co Emission

The improved solar reactor Sol@rmet allows to investigate the reduction of MgO in presence of carbon using concentrated solar energy in low vacuum conditions close to 900 Pa. The influence of the carbon type was studied and it was shown that a carbon issued from a biomass source was a great candidate. A gradual increase of the temperature during experiment allowed to obtain promising results. Powders with a high Mg content up to 97 m% and a high yield rate up to 50% were collected. Short time experiments at fixed locations under the focus of the solar concentrator were performed in order to obtain information on the kinetics of the carbothermal reduction of MgO. Notably, these experiments have underlined the temperature effect on the CO emission. 50 to 80% of the CO emission mainly occurred in 100 s after the beginning of the experiments. The phase boundary reaction between MgO and C appeared to be the dominant process at the initial stage of the carbothermal reduction. Calculated activation energy of this process is around 260 kJ mol-1.

Carbothermal reduction of alkali hydroxides using concentrated solar energy

Energy ◽  
2001 ◽  
Vol 26 (5) ◽  
pp. 441-455 ◽  
Author(s):  
Michael Epstein ◽  
Amnon Yogev ◽  
Chengcai Yao ◽  
Alexander Berman
Keyword(s):  
Solar Energy ◽  
Carbothermal Reduction ◽  
Concentrated Solar Energy ◽  
Alkali Hydroxides

scholarly journals Production of Si by vacuum carbothermal reduction of SiO2 using concentrated solar energy

JOM ◽  
2010 ◽  
Vol 62 (9) ◽  
pp. 49-54 ◽  
Author(s):  
Peter G. Loutzenhiser ◽  
Ozan Tuerk ◽  
Aldo Steinfeld
Keyword(s):  
Solar Energy ◽  
Carbothermal Reduction ◽  
Concentrated Solar Energy

STUDI PERAKITAN KELAPA HIBRIDA GSK x DMT BERDASARKAN PENANDA RAPD (RANDOMLY AMPLIFIED POLYMORPHIC DNA)

EUGENIA ◽  
2008 ◽  
Vol 14 (1) ◽  
Author(s):  
Semuel D. Runtunuwu ◽  
Hengky Novarianto ◽  
Heldering Tampake ◽  
Edy F. Lengkong
Keyword(s):  
Dna Marker ◽  
Rapd Marker ◽  
High Yield ◽  
Randomly Amplified Polymorphic Dna ◽  
Germination Time ◽  
Flower Production ◽  
Short Time

ABSTRACT   Runtunuwu, S.D. et al. 2008. Assembling Hybrid Coconut of GSK x DMT Based on RAPD (RANDOMLY AMPLIFIED POLYMORPHIC DNA) Marker. Eugenia 14 (1) : 134-152.   The aimed of this research was : 1. assembling hybrid coconut GSK x DMT (Genjah Salak x Dalam Mapanget) that seeds growth was relatifly homogeneous based on RAPD (Randomly Amplified Polymorphic DNA) marker and 2. to found the assembling method of hybrid coconut that will produce massive seeds relatifely short time will homogeneous plant. It was 65 individu trees observe for the average of famale flower per bunch. The result was 25 individu of coconut GSK has the average flower production > 40 per bunch was analyze the homogeneous genetic with the RAPD marker. Based on the analyze RAPD that were 25 individu of GSK coconut trees have the same genetic average 88 % and 14 individu among that was 100 % have same genetic. Further more that 14 individu of GSK was crossing with the 3 individu of DMT that have high yield per year its was DMT 1188, 1172 and 781. Based on the evaluation for the color of buds, high of buds, the steam circle, the petiole color and the germination time of hybrid coconut seeds from the crossing of GSK x DMT 1188 produce more than    70 % seeds that have same genetic, also for crossing of GSK x DMT 1172 have 9 combination and have more than 70 % that same genetic, 10 combination from crossing GSK x DMT 781 have more than 80 % same seeds growth. Therefore, using the RAPD marker were successfully produced 28 crossing of the hybrid coconut GSK x DMT that have relatifly homogeneous seeds growth.   Keywords : assembling, hybrid coconut GSK x DMT, RAPD.

scholarly journals Waste and Solar Energy: An Eco-Friendly Way for Glass Melting

2021 ◽  
Vol 5 (2) ◽  
pp. 16
Author(s):  
Isabel Padilla ◽  
Maximina Romero ◽  
José I. Robla ◽  
Aurora López-Delgado
Keyword(s):  
Solar Energy ◽  
Environmental Sustainability ◽  
Raw Materials ◽  
Glass Melting ◽  
Glass Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Concentrated Solar Energy ◽  
Calcium Source ◽  
The Aluminum Industry

In this work, concentrated solar energy (CSE) was applied to an energy-intensive process such as the vitrification of waste with the aim of manufacturing glasses. Different types of waste were used as raw materials: a hazardous waste from the aluminum industry as aluminum source; two residues from the food industry (eggshell and mussel shell) and dolomite ore as calcium source; quartz sand was also employed as glass network former. The use of CSE allowed obtaining glasses in the SiO2-Al2O3-CaO system at exposure time as short as 15 min. The raw materials, their mixtures, and the resulting glasses were characterized by means of X-ray fluorescence, X-ray diffraction, and differential thermal analysis. The feasibility of combining a renewable energy, as solar energy and different waste for the manufacture of glasses, would highly contribute to circular economy and environmental sustainability.

Behavior of a Heat-Protective Material Based on Al2O3 and SiO2 Fibers under Exposure to Concentrated Solar Energy Flux

2021 ◽  
Author(s):  
S. Kh. Suleimanov ◽  
V. G. Babashov ◽  
M. U. Dzhanklich ◽  
V. G. Dyskin ◽  
M. I. Daskovskii ◽  
...  
Keyword(s):  
Solar Energy ◽  
Energy Flux ◽  
Protective Material ◽  
Concentrated Solar Energy ◽  
Solar Energy Flux

scholarly journals Solid-State Redox Kinetics of CeO2 in Two-Step Solar CH4 Partial Oxidation and Thermochemical CO2 Conversion

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 723
Author(s):  
Mahesh Muraleedharan Nair ◽  
Stéphane Abanades
Keyword(s):  
Solid State ◽  
Solar Energy ◽  
Kinetic Models ◽  
Oxygen Carrier ◽  
Co2 Conversion ◽  
Oxidation Reactions ◽  
Redox Kinetics ◽  
Concentrated Solar Energy ◽  
Ceria Reduction ◽  
Kinetics Of

The CeO2/CeO2−δ redox system occupies a unique position as an oxygen carrier in chemical looping processes for producing solar fuels, using concentrated solar energy. The two-step thermochemical ceria-based cycle for the production of synthesis gas from methane and solar energy, followed by CO2 splitting, was considered in this work. This topic concerns one of the emerging and most promising processes for the recycling and valorization of anthropogenic greenhouse gas emissions. The development of redox-active catalysts with enhanced efficiency for solar thermochemical fuel production and CO2 conversion is a highly demanding and challenging topic. The determination of redox reaction kinetics is crucial for process design and optimization. In this study, the solid-state redox kinetics of CeO2 in the two-step process with CH4 as the reducing agent and CO2 as the oxidizing agent was investigated in an original prototype solar thermogravimetric reactor equipped with a parabolic dish solar concentrator. In particular, the ceria reduction and re-oxidation reactions were carried out under isothermal conditions. Several solid-state kinetic models based on reaction order, nucleation, shrinking core, and diffusion were utilized for deducing the reaction mechanisms. It was observed that both ceria reduction with CH4 and re-oxidation with CO2 were best represented by a 2D nucleation and nuclei growth model under the applied conditions. The kinetic models exhibiting the best agreement with the experimental reaction data were used to estimate the kinetic parameters. The values of apparent activation energies (~80 kJ·mol−1 for reduction and ~10 kJ·mol−1 for re-oxidation) and pre-exponential factors (~2–9 s−1 for reduction and ~123–253 s−1 for re-oxidation) were obtained from the Arrhenius plots.

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