The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Amin Azdarpour - One of the best experts on this subject based on the ideXlab platform.
-
Direct and inDirect aqueous mineralization using red gypsum for carbon dioxide sequestration
2015Co-Authors: Amin AzdarpourAbstract:Carbon capture and storage is gaining prominence as a means of combating climate change. Mineral Carbonation is the only known form of permanent and leakage-free carbon storage. The aim of this research was to investigate the suitability and feasibility of utilizing red gypsum as the calcium source for the mineral Carbonation process. The physico-chemical analysis of red gypsum showed that calcium and iron are its major constituents, which makes it a highly suitable and potential feedstock for mineral Carbonation. The Direct Carbonation of red gypsum showed that both the purity of the product and the efficiency of the reaction were very low even at elevated reaction temperature and CO2 pressure. The maximum CaCO3 purity of 23.63% and Carbonation efficiency of 41.04% were achieved during Direct aqueous Carbonation of red gypsum. The red gypsum dissolution studies showed that H2SO4 resulted in higher calcium extraction efficiency compared to HCl and HNO3. Increasing the reaction temperature from 30 °C to 70 °C and also increasing the reaction time from 5 to 120 minutes were found to be effective in enhancing the degree of extraction for all three types of acid used. The maximum of 100% and 84.6% extraction efficiency was achieved for Ca and Fe, respectively. Kinetic analysis found that the dissolution rate of red gypsum is controlled by the combination of product layer diffusion and chemical reaction control. The Carbonation efficiency was found to be in Direct relationship with CO2 pressure where the maximum Carbonation efficiency of 100% was achieved at 8 bar CO2 pressure. The pH swing experiments resulted in CaCO3 with a maximum purity of 98%. The pH swing Carbonation of red gypsum could be further investigated as a promising method for large scale CO2 sequestration.
-
Direct Carbonation of red gypsum to produce solid carbonates
Fuel Processing Technology, 2014Co-Authors: Amin Azdarpour, Mohammad Asadullah, Radzuan Junin, Muhammad A Manan, Hossein Hamidi, Erfan MohammadianAbstract:article i nfo This study focuses on Direct mineral Carbonation of waste gypsum, a by-product of titanium dioxide production industry and known as red gypsum. The red gypsum is a potential raw material for Carbonation with carbon dioxide due to its high content of calcium. Before being used the red gypsum, it was characterized by MASTERSIZER2000,XRD,andXRFanalyses.TheCarbonationofredgypsumwascarriedoutusingahighpressure autoclavereactor.ThereactionparameterssuchasCO2pressure,reaction temperature andredgypsum particlesize were optimized to achieve the maximum yield and purity of calcium carbonate. The purity of calcium carbonate produced and the Carbonation efficiency at different temperatures have also been investigated. Both the purity of the product and the efficiency of the reaction were increased when elevated CO2 pressure and reduced particle size were used. They were increased initially with increasing temperature up to 200 °C, but dropped with further increase of temperature. The mineral Carbonation technology by using red gypsum can potentially contribute to both reduction of CO2 emission and remediation of environmental concern.
Mohammad Reza Ganjali - One of the best experts on this subject based on the ideXlab platform.
-
Preparation of dysprosium carbonate and dysprosium oxide efficient photocatalyst nanoparticles through Direct Carbonation and precursor thermal decomposition
Journal of Materials Science: Materials in Electronics, 2017Co-Authors: Mehdi Rahimi-nasrabadi, Mohammad Reza Ganjali, Seied Mahdi Pourmortazavi, Parviz Novrouzi, Farnoosh Faridbod, Meisam Sadeghpour KarimiAbstract:Dysprosium carbonate nanoparticles were prepared through a Direct precipitation method using Dy(NO_3)_3 and Na_2CO_3 as a facile, well-regulated and cost-effective technique for the production insoluble salts. Due to the importance of improving the capability and quality of a process for adjusting the size of the product particles the optimal precipitation reaction parameters were evaluated through the Taguchi method. The reaction conditions like the concentrations of the reacting species, the rate of the addition of the reagent as well as the reactor temperature were also optimized based on an orthogonal array design. It was concluded from the results that dysprosium carbonate nanoparticles can be synthesized through the Direct Carbonation process by controlling the concentration of carbonate ion, the rate of its addition to the reactor and the reaction temperature. Further, a one-step thermal decomposition method was used for the efficient conversion of dysprosium carbonate to dysprosium oxide nanoparticles. The characterization of the products was carried out through XRD, SEM, TEM, FT-IR and thermal analysis techniques. Furthermore, the as-synthesized dysprosium carbonate and dysprosium oxide nanoparticles were used as photocatalyst for the photocatalytic degradation of methylene orange under ultraviolet light.
-
preparation of nanosized chromium carbonate and chromium oxide green pigment through Direct Carbonation and precursor thermal decomposition
Journal of Molecular Liquids, 2016Co-Authors: Mehdi Rahiminasarabadi, Farhad Ahmadi, Sorayya Hamdi, Neda Eslami, Khadijeh Didehban, Mohammad Reza GanjaliAbstract:Abstract Chromium carbonate nanoparticles were prepared through the Direct precipitation method. Due to the importance of improving the capability and quality of a process for adjusting size of the product particles the optimal precipitation reaction parameters were evaluated using the parameter design of the Taguchi method. Reaction conditions like the concentrations of the reacting species, the rate of the addition of the reagent as well as the reactor temperature were optimized using the orthogonal array design. It was concluded from the results that chromium carbonate nanoparticles can be synthesized via Direct Carbonation process while controlling the concentrations of chromium and carbonate ion solutions and the reaction temperature. Further, a one-step thermal decomposition method was used for the efficient conversion of chromium carbonate to chromium oxide nanoparticles. The characterization studies of the products were performed through X-ray diffraction, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy and thermal analysis techniques.
Soo Chun Chae - One of the best experts on this subject based on the ideXlab platform.
-
precipitation of calcium carbonate during Direct aqueous Carbonation of flue gas desulfurization gypsum
Chemical Engineering Journal, 2012Co-Authors: Kyungsun Song, Youngnam Jang, Dongbok Shin, Junhwan Bang, Chi Wan Jeon, Soo Chun ChaeAbstract:Abstract The precipitation of calcium carbonate during the Direct aqueous Carbonation of flue gas desulfurization (FGD) gypsum, an industrial waste product, was investigated. For comparison, two-step Carbonation was also attempted. Calcite was the dominating phase produced in the two-step Carbonation, while the Direct Carbonation produced a mixture of vaterite and calcite phases under all conditions. The relative amounts of each phase were determined by comparing their X-ray diffraction peak intensities. The amount of vaterite phase in the mixture was found to increase with Carbonation time for a fixed CO 2 flow rate. An induction period before the precipitation of physically detectable calcium carbonate crystals was assessed using X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FE-SEM). For the CO 2 flow rate of 1 L/min, the C1s peak of CaCO 3 became clear after Carbonation took place for longer than 15 min. Virtually impurity-free, single-phase calcite crystals were precipitated from the solution extracted during the induction period. The amount of calcite obtained was typically 5.3% of the amount that can be obtained in the case of the complete reaction. However, further elaboration of this method may allow for the preparation of pure calcite crystals from industrial by-product FGD gypsum.
Erfan Mohammadian - One of the best experts on this subject based on the ideXlab platform.
-
Direct Carbonation of red gypsum to produce solid carbonates
Fuel Processing Technology, 2014Co-Authors: Amin Azdarpour, Mohammad Asadullah, Radzuan Junin, Muhammad A Manan, Hossein Hamidi, Erfan MohammadianAbstract:article i nfo This study focuses on Direct mineral Carbonation of waste gypsum, a by-product of titanium dioxide production industry and known as red gypsum. The red gypsum is a potential raw material for Carbonation with carbon dioxide due to its high content of calcium. Before being used the red gypsum, it was characterized by MASTERSIZER2000,XRD,andXRFanalyses.TheCarbonationofredgypsumwascarriedoutusingahighpressure autoclavereactor.ThereactionparameterssuchasCO2pressure,reaction temperature andredgypsum particlesize were optimized to achieve the maximum yield and purity of calcium carbonate. The purity of calcium carbonate produced and the Carbonation efficiency at different temperatures have also been investigated. Both the purity of the product and the efficiency of the reaction were increased when elevated CO2 pressure and reduced particle size were used. They were increased initially with increasing temperature up to 200 °C, but dropped with further increase of temperature. The mineral Carbonation technology by using red gypsum can potentially contribute to both reduction of CO2 emission and remediation of environmental concern.
Claudio J A Mota - One of the best experts on this subject based on the ideXlab platform.
-
Direct Carbonation of glycerol with co2 catalyzed by metal oxides
ChemPhysChem, 2017Co-Authors: Leonardo P Ozorio, Claudio J A MotaAbstract:Five metal oxides (ZnO, SnO2, Fe2O3, CeO2, La2O3) were produced by the sol–gel method and tested in the Direct Carbonation of glycerol with CO2. Initial tests with Fe2O3 showed that the best reaction condition was 180 °C, 150 bar, and 12 h. The other oxides were evaluated at these conditions and were all active to the formation of glycerol carbonate. Zinc oxide was the most active catalyst, with a yield of 8.1 % in the organic carbonate. The catalytic activity decreased upon washing and drying the ZnO catalyst between the runs. Nevertheless, the activity is maintained if the ZnO is washed and calcined at 450 °C between the runs. FTIR and TGA results indicated the formation of ZnCO3 as the main cause of catalyst deactivation, which may be decomposed upon calcination of the material. No appreciable leaching of Zn was observed, indicating a truly heterogeneous catalysis.
-
metal impregnated zeolite y as efficient catalyst for the Direct Carbonation of glycerol with co2
Applied Catalysis A-general, 2015Co-Authors: Leonardo P Ozorio, Rafael Pianzolli, Luciana Da Cruz Machado, Jussara L Miranda, Cassia Curan Turci, Antonio C O Guerra, Falabella E Souzaaguiar, Claudio J A MotaAbstract:Abstract Metal-impregnated zeolite Y catalysts were prepared by treatment of a NaY zeolite with an aqueous solution of AgNO 3 , Zn(NO 3 ) 2 and SnCl 2 , followed by water evaporation. The materials were then calcined in air at 450 °C and evaluated in the reaction of CO 2 with glycerol at 180 °C for 3 h at 100 Bar. The parent NaY zeolite was inactive under these conditions, but the metal-impregnated zeolites, as well as the calcined salt precursors, showed yields of glycerol carbonate up to 5.8%. The TON of the zeolite catalysts were significantly higher than that of the calcined salts, suggesting the formation of a highly active metal oxide phase at the external surface of the zeolite.