scholarly journals Development of Carbonization and a Relatively High-Temperature Halogenation Process for the Removal of Radionuclides from Spent Ion Exchange Resins

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 96
Author(s):  
Hee-Chul Yang ◽  
Hyeon-Oh Park ◽  
Kyu-Tae Park ◽  
Sung-Jun Kim ◽  
Hyung-Ju Kim ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Cation Exchange ◽  
Treatment Process ◽  
Flow Reactor ◽  
Thermochemical Treatment ◽  
Operating Conditions ◽  
Equilibrium Analysis ◽  
Optimum Operating ◽  
Radioactive Elements ◽  
Exchange Resins

This study investigated a two-step thermochemical treatment process consisting of carbonization and halogenation for the removal of radionuclides from spent cation-exchange resin (CER). Based on a thermal analysis of cation-exchange resins, we propose a two-step thermochemical treatment process involving the conversion of spent CER into pyrocarbon and then the removal of radioactive elements from the carbonized CER by converting them volatile halides at very high temperatures. The proposed process mainly consists of a carbonization and halogenation reactor, a UHC (unburned hydrocarbon) combustor, and wet scrubber. A step-by-step experimental and numerical optimization study was conducted with the carbonization and halogenation reactor and the UHC combustor. The optimum operating conditions could be established based on the results of a thermal analysis of the CER, a nonisothermal kinetic analysis, a numerical modeling study of a plug flow reactor (PFR)-type combustor, and a thermodynamic equilibrium analysis of a system consisting of a mix of carbonized CER and halogenation gas. The results of this study present detailed design of a novel multifunctional reactor and operating conditions of a bench-scale carbonization and halogenation process. Basic performance tests using CER doped with nonradioactive Co and Cs, indicated as Cs-137/134 and Co-60/58, were conducted under the optimized conditions. The results of these tests showed that the novel thermochemical process proposed in this study is a viable process that effectively removes radioactive elements from spent CER.

scholarly journals Characterization and Beneficiation of an Egyptian Nepheline Syenite Ore

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Abdel-Zaher M. Abouzeid ◽  
Abdel-Tawab A. Negm
Keyword(s):  
Magnetic Separation ◽  
Nepheline Syenite ◽  
Eastern Desert ◽  
Operating Conditions ◽  
Raw Material ◽  
Optimum Operating ◽  
Oxide Content ◽  
Radioactive Elements ◽  
Original Rock ◽  
Alumina Recovery

Nepheline syenite ore is an essential constituent in ceramics and glass raw material meals, as a flux and as a source of alumina. The natural nepheline syenite rocks contain some undesired minerals, which are usually eliminated or reduced to the allowable limits by beneficiation. The present paper is concerned with characterization and beneficiation of an Egyptian nepheline syenite rock, at Abu Khruq locality, Eastern Desert, Egypt. The ore is exceptionally hard, with high crushing strength of 875 kg/cm2, and iron oxide content of about 6.5%. The grain size of the constituents is relatively large. In some samples, the iron oxides are disseminated within the feldspars and nepheline syenite crystals, or in cracks and fissures within the feldspars crystals. The rock contains some environmental hazardous elements such as uranium, thorium, and radon. Magnetic separation and flotation techniques were applied, separately or in combination. Under optimum operating conditions, magnetic separation followed by reverse anionic flotation gave a concentrate assaying 0.2% Fe2O3 and about 24% Al2O3 at alumina recovery of about 80%. The radioactive elements were reduced in the concentrate to lower levels than their levels in the original rock.

Assessing the Catalytic Potential of 12-tungstophosphoric Acid Supported on MCM-41 for the Gas Phase Etherification of Alcohols

2017 ◽  
Vol 68 (7) ◽  
pp. 1442-1448
Author(s):  
Song Il Kong ◽  
Anca Borcea ◽  
Vasile Matei ◽  
Dragos Ciuparu
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Space Velocity ◽  
Butyl Alcohol ◽  
Tungstophosphoric Acid ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Fuel Additive ◽  
Weight Hourly Space Velocity ◽  
Mcm 41

The gas-phase etherification reaction of ethanol with tert-butyl alcohol (TBA) was investigated for the production of an oxygenated fuel additive. The reaction was carried out in a continuous flow reactor, in the presence of 12-tungstophosphoric acid (HPW) dispersed on MCM-41 as catalyst. We have studied the influence of temperature, ethanol:TBA mole ratio, and weight hourly space velocity (WHSV) on the TBA conversion and ETBE selectivity. The optimum operating conditions were found at 110oC temperature, 8:1 ethanol:TBA mole ratio in the feed, and 30% HPW loading on the catalyst. The highest ETBE yield values were obtained at 110 �C and WHSV of 46 h-1 and 42 h-1. The HPW/MCM-41 catalyst showed good activity and on-stream stability for the gas-phase synthesis of ETBE at 110oC, thus it is a promising catalyst for etherification reactions and, potentially, for other gas phase acid-catalyzed reactions.

Study on Operating Conditions of Membrane-Aerated Bioreactor

2012 ◽  
Vol 581-582 ◽  
pp. 1193-1196
Author(s):  
Xue Jing Liu ◽  
Shi Chang Xu ◽  
Cheng Cheng Qiang ◽  
Baoan Li
Keyword(s):  
Water Treatment ◽  
Research And Development ◽  
Treatment Process ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Technical Feasibility ◽  
Technology Program ◽  
Main Operating

A membrane-aerated bioreactor (MABR) has the technical feasibility of water treatment. This paper systematically studies the main operating conditions impact on the MABR process of dealing with wastewater to determine the optimum operating conditions, and made the possible implementation of the technology program. The results lay a good foundation for further research and development of MABR treatment process and technology.

Influence of the operating conditions of the intermediate thermal hydrolysis on the energetic efficiency of the sludge treatment process

2021 ◽  
Vol 333 ◽  
pp. 125114
Author(s):  
Israel Díaz ◽  
Alina Díaz-Curbelo ◽  
Kevin Ignacio Matute ◽  
María Fdz-Polanco ◽  
Sara Isabel Pérez-Elvira
Keyword(s):  
Treatment Process ◽  
Operating Conditions ◽  
Energetic Efficiency ◽  
Thermal Hydrolysis ◽  
Sludge Treatment

Finite element method estimation of temperature distribution of automotive tire using one-way-coupled method

2021 ◽  
pp. 095440702110087
Author(s):  
Zumrat Usmanova ◽  
Emin Sunbuloglu
Keyword(s):  
Thermal Analysis ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Complex Geometry ◽  
Rolling Resistance ◽  
Operating Conditions ◽  
Deformation Analysis ◽  
Coupled Method ◽  
Experimental Values ◽  
Hysteretic Loss

Numerical simulation of automotive tires is still a challenging problem due to their complex geometry and structures, as well as the non-uniform loading and operating conditions. Hysteretic loss and rolling resistance are the most crucial features of tire design for engineers. A decoupled numerical model was proposed to predict hysteretic loss and temperature distribution in a tire, however temperature dependent material properties being utilized only during the heat generation analysis stage. Cyclic change of strain energy values was extracted from 3-D deformation analysis, which was further used in a thermal analysis as input to predict temperature distribution and thermal heat generation due to hysteretic loss. This method was compared with the decoupled model where temperature dependence was ignored in both deformation and thermal analysis stages. Deformation analysis results were compared with experimental data available. The proposed method of numerical modeling was quite accurate and results were found to be close to the actual tire behavior. It was shown that one-way-coupled method provides rolling resistance and peak temperature values that are in agreement with experimental values as well.

Study on the Alkoxylation of Dihydromyrcene over Cation Exchange Resins

2019 ◽  
Vol 58 (27) ◽  
pp. 11871-11877 ◽  
Author(s):  
Si Chen ◽  
Su Wang ◽  
Zheng Zhou ◽  
Gaodong Yang ◽  
Zhibing Zhang
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Resins ◽  
Exchange Resins
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