Multitube Rotary Kiln for the Industrial Solar Production of Lime

2005 ◽  
Vol 127 (3) ◽  
pp. 386-395 ◽  
Author(s):  
Anton Meier ◽  
Enrico Bonaldi ◽  
Gian Mario Cella ◽  
Wojciech Lipinski

We designed and tested a scaleable solar multitube rotary kiln to effect the endothermic calcination reaction CaCO3→CaO+CO2 at above 1300K. The indirect heating 10-kW reactor prototype processes 1-5mm limestone particles, producing high purity lime of any desired reactivity and with a degree of calcination exceeding 98%. The reactor’s efficiency, defined as the enthalpy of the calcination reaction at ambient temperature (3184kJkg−1) divided by the solar energy input, reached 30%–35% for solar flux inputs of about 2000kWm−2 and for quicklime production rates up to 4kgh−1. The use of concentrated solar energy in place of fossil fuels as the source of process heat has the potential of reducing by 20% CO2 emissions in a state-of-the-art lime plant and by 40% in a conventional cement plant.

Solar Energy ◽  
1999 ◽  
Vol 67 (1-3) ◽  
pp. 119-130 ◽  
Author(s):  
J.G. Pieters ◽  
J.M. Deltour

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 480
Author(s):  
Hossein Yousefi ◽  
Mohamad Aramesh ◽  
Bahman Shabani

This study presents a novel, highly detailed, and accurate modelling method for calculation of the total annual solar thermal energy received by a double-slope solar still. The model is further utilized for sensitivity analysis and optimization with the help of Genetic Algorithm and TOPSIS methods. The model reveals that the main parameters that can independently affect solar energy input are the basin length, width, tilt angle, surface azimuth angle, and the glass covers’ inclination angle. The sensitivity of the annual solar energy input to all these parameters is analyzed. Moreover, all the parameters are chosen to be involved in the optimization problem. Sensitivity analysis results show that except for basin azimuth angle all other parameters significantly affect the amount of energy input to the solar still. Genetic Algorithm identified 60 optimum sets of parameters, one of which was selected by the TOPSIS method. The optimum values for the basin width, length, tilt and azimuth angles, and the inclination angles of the two glass covers are 2 m, 2 m, 8°, 180°, 80° and 67°, respectively. This design of a double-slope solar still will receive an annual total of 97.67 GJ solar energy input.


2021 ◽  
Vol 5 (2) ◽  
pp. 16
Author(s):  
Isabel Padilla ◽  
Maximina Romero ◽  
José I. Robla ◽  
Aurora López-Delgado

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.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 931
Author(s):  
Yin Xu ◽  
Giovanni Zangari

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.


Author(s):  
S. Kh. Suleimanov ◽  
V. G. Babashov ◽  
M. U. Dzhanklich ◽  
V. G. Dyskin ◽  
M. I. Daskovskii ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 87-113
Author(s):  
Rami J. Batrice ◽  
John C. Gordon

Solar energy has been used for decades for the direct production of electricity in various industries and devices. However, harnessing and storing this energy in the form of chemical bonds has emerged as a promising alternative to fossil fuels.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 723
Author(s):  
Mahesh Muraleedharan Nair ◽  
Stéphane Abanades

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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