Solubilities of Methane, Nitrogen, Carbon Dioxide, and a Natural Gas Mixture in Aqueous Sodium Bicarbonate Solutions under High Pressure and Elevated Temperature

1997 ◽  
Vol 42 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Jun Gao ◽  
Da-Qing Zheng ◽  
Tian-Min Guo
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Elevated Temperature ◽  
Natural Gas ◽  
Sodium Bicarbonate ◽  
Gas Mixture ◽  
Aqueous Sodium ◽  
Aqueous Sodium Bicarbonate ◽  
Bicarbonate Solutions

Comprehensive study of the toothpaste containing fluoride and 67% aqueous sodium bicarbonate solution

2021 ◽  
Vol 26 (2) ◽  
pp. 137-143
Author(s):  
S. N. Gromova ◽  
N. A. Guzhavina ◽  
E. A. Falaleeva ◽  
E. P. Kolevatykh ◽  
А. V. Elikov ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Oral Care ◽  
Sodium Bicarbonate Solution ◽  
Comprehensive Treatment ◽  
Aqueous Sodium ◽  
Aqueous Sodium Bicarbonate ◽  
Periodontal Inflammation ◽  
Aqueous Sodium Bicarbonate Solution ◽  
Inflammatory Effect

Relevance. A wide variety of oral care products is available nowadays. Sometimes aggressive advertising rather than doctor’s advice determines our patients’ choice. In our research, we provide evidence of the clinical use of toothpaste containing fluoride and sodium bicarbonate.Materials and methods. During four weeks, we followed up a group of students who used the toothpaste containing 1400 ppm fluoride and 67% aqueous sodium bicarbonate solution. The clinical, biochemical and microbiological tests and saliva crystallization score assessed the characteristics stated by the manufacturer.Results. The statistically significant correlation between all studied criteria is evidence of the effectiveness of the toothpaste. In addition to the significant remineralization and antiplaque effect, biochemical and microbiological tests confirmed the anti-inflammatory effect of the toothpaste. An immediate cleaning effect was observed after the first brushing as well as in long-term use.Conclusion. Improvement of oral hygiene indices and reduction of periodontal inflammation confirmed the successful result of the comprehensive treatment of chronic gingivitis.

Investigations of Gaseous Alternative Fuels at Atmospheric and Elevated Temperature and Pressure Conditions

2010 ◽  
Author(s):  
Audrius Bagdanavicius ◽  
Nasser Shelil ◽  
Philip J. Bowen ◽  
Nick Syred ◽  
Andrew P. Crayford
Keyword(s):  
Carbon Dioxide ◽  
Elevated Temperature ◽  
Turbulence Intensity ◽  
Alternative Fuels ◽  
Burning Velocity ◽  
Gas Mixture ◽  
Bunsen Burner ◽  
Swirl Burner ◽  
Temperature And Pressure ◽  
Methane Carbon

Increasing interest in alternative fuels for gas turbines stimulates research in gaseous fuels other than natural gas. Various gas mixtures, based on methane as the main component, are considered as possible fuels in the future. In particular, methane enrichment with hydrogen or dilution with carbon dioxide is of considerable interest. Some experiments and numerical calculations have been undertaken to investigate methane-hydrogen and methane-carbon dioxide gas flames, however most of these investigations are limited by particular pressure or temperature conditions. This paper presents the investigation of the combustion of methane–carbon dioxide mixtures at atmospheric and elevated temperature and pressure conditions. Two experimental rigs were used, a Bunsen burner and swirl burner. Bunsen burner experiments were performed in the High Pressure Optical Chamber, which is located within the Gas Turbine Research Centre of Cardiff University — at 3 bara and 7 bara pressure, and 473 K, 573 K and 673 K temperature conditions for lean and rich mixtures. Planar Laser Tomography (PLT) was applied to investigate turbulent burning velocity. Burning velocity of the gas mixture was calculated using two different image processing techniques and the difference in the results obtained using these two techniques is presented and discussed. Laser Doppler anemometry (LDA) was utilised to define turbulence characteristics such as turbulence intensity and integral length scale. Due to the variability of the velocity flow field and turbulence intensity across Bunsen burners, the importance of measuring position and conditions is discussed. The sensitivity of this variance on the flame regime as defined in the Borghi diagram is evaluated. In the second part of the study, a generic swirl burner was used to define the flame flashback limits for methane–carbon dioxide mixtures at atmospheric conditions. The gas mixture stability graphs are plotted, and the effect of CO2 addition are discussed.

High Pressure Supercritical Carbon Dioxide Separation from its Mixture with Nitrogen at Different Temperatures

2020 ◽  
Vol 1008 ◽  
pp. 1-14
Author(s):  
Rehab M. El-Maghraby ◽  
Mahmoud Ramzy ◽  
Ahmed K. Aboul-Gheit
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Membrane Separation ◽  
Point Sources ◽  
Gas Mixture ◽  
Carbon Dioxide Separation ◽  
Different Temperatures ◽  
Supercritical Phase ◽  
High Concentrations ◽  
Set Up

Carbon dioxide (CO2) capturing from point sources is currently being proposed as a way to minimize CO2 emissions to the atmosphere. Carbon dioxide is considered one of the greenhouse gases that affects our environment. Legislations are being enforced in many countries to limit CO2 emissions to the atmosphere. Two methods are mostly used for CO2 capturing from flue gases and natural gases; the first method is absorption using amine-based solvents, while the second is membrane separation. The first method is effective for CO2 separation from gas mixtures with low CO2 concentration in the range of 10 to 20%, while the other can handle gas mixture with intermediate CO2 concentration but there is a limit on the CO2 purity. Hence, such methods cannot be used in pre-combustion and oxy fuel technologies where a more concentrated CO2 gas stream is produced. Throughout this work, a new method is introduced to separate carbon dioxide from its mixture with nitrogen (N2) at high concentrations, 90 mol.% CO2 and 10 mol.% N2 gas mixture. A customized high-pressure experimental set-up was built. Three temperature were tested: 15 °C, 25 °C and 38 °C at 150 bar. At such condition CO2 will be in the liquid and the supercritical phase respectively. The composition of the top and bottom streams where analyzed. The amount of CO2 in the top stream was the smallest at the supercritical condition. In addition, the purity of CO2 in the bottom stream was the highest at 38 °C and 150 bars, when CO2 is at the supercritical phase.

THE EVOLUTION OF CARBON DIOXIDE IN THE A.-C. ELECTROLYSIS OF SODIUM CARBONATE AND BICARBONATE SOLUTIONS, AND THE DISCHARGE POTENTIALS OF CARBONATE AND BICARBONATE IONS

1934 ◽  
Vol 11 (4) ◽  
pp. 539-546
Author(s):  
J. W. Shipley
Keyword(s):  
Carbon Dioxide ◽  
Sodium Bicarbonate ◽  
Sodium Carbonate ◽  
Current Flow ◽  
Platinum Electrodes ◽  
Sodium Salts ◽  
Bicarbonate Ions ◽  
Carbonate Solutions ◽  
Bicarbonate Solutions ◽  
Discharge Potential

The a.-c. electrolysis of sodium carbonate solutions at voltages as high as 110, even when arcing occurs on the electrodes, does not cause the evolution of carbon dioxide. In the a.-c. electrolysis of aqueous bicarbonate solutions with platinum electrodes, hydrogen, oxygen and carbon dioxide are evolved freely until all the bicarbonate has been transformed to carbonate, after which the evolution of carbon dioxide ceases and only hydrogen and oxygen are given off. In a.-c. electrolysis of sodium bicarbonate solutions and solutions of the sodium salts of aliphatic acids, a deposit of finely divided platinum is formed on the electrodes. This deposit inhibits the evolution of carbon dioxide, hydrogen and oxygen, but does not affect the current flow. The decomposition potential of bicarbonate solutions in respect to the evolution of carbon dioxide on smooth platinum and with d.c. was found to be 2.2 volts, and of carbonate solutions, 3.5 volts. The anodic discharge potential of HCO3− is − 1.45 to − 1.50 volts, and of CO3−−, − 1.90 to − 1.95 volts. The evolution of carbon dioxide does not appear to cause any polarizing effect on the anode.

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