scholarly journals Influence of parameters of gas mixture on the size of forming carbon dioxide crystalls

2016 ◽  
pp. 1-5
Author(s):  
M.M. Danilov ◽  
A.S. Nazarova
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture

Preservation of freshness of yellowtail fillet packaged using carbon dioxide-nitrogen gas mixture

1989 ◽  
Vol 2 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Matsui Yasuda ◽  
Hajime Nishino ◽  
Tokiko Chiba ◽  
Hisako Nakano ◽  
Michio Yokoyama
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture ◽  
Nitrogen Gas

scholarly journals Molecular Simulations of CO2/CH4, CO2/N2 and N2/CH4 Binary Mixed Hydrates

2021 ◽  
Vol 83 (3) ◽  
pp. 372-378
Author(s):  
A. A. Sizova ◽  
S. A. Grintsevich ◽  
M. A. Kochurin ◽  
V. V. Sizov ◽  
E. N. Brodskaya
Keyword(s):  
Carbon Dioxide ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Gas Hydrates ◽  
Molecular Simulations ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Grand Canonical Monte Carlo ◽  
Multicomponent Gas ◽  
Grand Canonical

Abstract Grand canonical Monte Carlo simulations were performed to study the occupancy of structure I multicomponent gas hydrates by CO2/CH4, CO2/N2, and N2/CH4 binary gas mixtures with various compositions at a temperature of 270 K and pressures up to 70 atm. The presence of nitrogen in the gas mixture allows for an increase of both the hydrate framework selectivity to CO2 and the amount of carbon dioxide encapsulated in hydrate cages, as compared to the CO2/CH4 hydrate. Despite the selectivity to CH4 molecules demonstrated by N2/CH4 hydrate, nitrogen can compete with methane if the gas mixture contains at least 70% of N2.

A Comprehensive Review on CO2/N2 Mixture Injection for Methane Gas Recovery in Hydrate Reservoirs

2021 ◽  
Author(s):  
Azeez Gbenga Aregbe ◽  
Ayoola Idris Fadeyi
Keyword(s):  
Carbon Dioxide ◽  
Gas Production ◽  
Gas Mixture ◽  
Methane Gas ◽  
Gas Recovery ◽  
Oceanic Sediments ◽  
Replacement Process ◽  
The World ◽  
Gas Molecules ◽  
Hydrate Reservoirs

Abstract Clathrate hydrates are non-stoichiometric compounds of water and gas molecules coexisting at relatively low temperatures and high pressures. The gas molecules are trapped in cage-like structures of the water molecules by hydrogen bonds. There are several hydrate deposits in permafrost and oceanic sediments with an enormous amount of energy. The energy content of methane in hydrate reservoirs is considered to be up to 50 times that of conventional petroleum resources, with about 2,500 to 20,000 trillion m3 of methane gas. More than 220 hydrate deposits in permafrost and oceanic sediments have been identified to date. The exploration and production of these deposits to recover the trapped methane gas could overcome the world energy challenges and create a sustainable energy future. Furthermore, global warming is a major issue facing the world at large and it is caused by greenhouse gas emissions such as carbon dioxide. As a result, researchers and organizations have proposed various methods of reducing the emission of carbon dioxide gas. One of the proposed methods is the geological storage of carbon dioxide in depleted oil and gas reservoirs, oceanic sediments, deep saline aquifers, and depleted hydrate deposits. Studies have shown that there is the possibility of methane gas production and carbon dioxide storage in hydrate reservoirs using the injection of carbon dioxide and nitrogen gas mixture. However, the conventional hydrocarbon production methods cannot be used for the hydrate reservoirs due to the nature of these reservoirs. In addition, thermal stimulation and depressurization are not effective methods for methane gas production and carbon sequestration in hydrate-bearing sediments. Therefore, the gas replacement method for methane production and carbon dioxide storage in clathrate hydrate is investigated in this paper. The research studies (experiments, modeling/simulation, and field tests) on CO2/N2 gas mixture injection for the optimization of methane gas recovery in hydrate reservoirs are reviewed. It was discovered that the injection of the gas mixture enhanced the recovery process by replacing methane gas in the small and large cages of the hydrate. Also, the presence of N2 molecules significantly increased fluid injectivity and methane recovery rate. In addition, a significant amount of free water was not released and the hydrate phase was stable during the replacement process. It is an effective method for permanent storage of carbon dioxide in the hydrate layer. However, further research studies on the effects of gas composition, particle size, and gas transport on the replacement process and swapping rate are required.

scholarly journals Experimental Affective Symptoms in Panic Disorder Patients

2005 ◽  
Vol 50 (3) ◽  
pp. 175-178 ◽  
Author(s):  
Thea Overbeek ◽  
Koen Schruers ◽  
Ine Docters van Leeuwen ◽  
Tineke Klaassen ◽  
Eric Griez
Keyword(s):  
Carbon Dioxide ◽  
Panic Disorder ◽  
Outcome Measure ◽  
Gas Mixture ◽  
Comorbid Depression ◽  
Major Depressive ◽  
Symptoms Of Depression ◽  
Affective Symptoms ◽  
Challenge Tests ◽  
Panic Symptoms

Objective: To date, carbon dioxide (CO2) challenge tests in panic disorder (PD) patients have focused on anxiety as the sole outcome measure. This study assesses a broader range of symptoms in patients with PD. Method: We administered a gas mixture of 35% CO2 and 65% oxygen (O2) to 25 patients with PD. Nine patients met the criteria for a comorbid major depressive disorder (MDD), and 16 did not. We assessed not only subjects' symptoms of anxiety but also their symptoms of depression and aggression. Results: Baseline ratings did not differ across the 2 subgroups. Postchallenge ratings were higher for PD and MDD patients on all the assessed affective symptoms, except for specific panic symptoms. Conclusion: These findings suggest that, in addition to anxiety, CO2 challenge induces depressive and aggressive symptoms, specifically in PD patients with comorbid depression.

Removal of carbon dioxide from pressurized CO2–CH4 gas mixture using hollow fiber membrane contactors

2010 ◽  
Vol 351 (1-2) ◽  
pp. 21-27 ◽  
Author(s):  
Sayed A.M. Marzouk ◽  
Mohamed H. Al-Marzouqi ◽  
Muftah H. El-Naas ◽  
Nadia Abdullatif ◽  
Zahoor M. Ismail
Keyword(s):  
Carbon Dioxide ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Gas Mixture ◽  
Fiber Membrane ◽  
Membrane Contactors

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.

Carbon dioxide capture in the presence of water by an amine-based crosslinked porous polymer

2018 ◽  
Vol 6 (15) ◽  
pp. 6455-6462 ◽  
Author(s):  
Mahmoud M. Abdelnaby ◽  
Ahmed M. Alloush ◽  
Naef A. A. Qasem ◽  
Bassem A. Al-Maythalony ◽  
Rached B. Mansour ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Capture ◽  
Organic Materials ◽  
Carbon Dioxide Capture ◽  
Porous Polymer ◽  
Gas Mixture

A new cross-linked porous polymer was synthesized and its performance in the capture of carbon dioxide from a ternary gas mixture was demonstrated, and properties retained for over 45 cycles. This report represents one of the top performing porous organic materials for carbon capture.

Ultraviolet Spectral Analysis and Quantitative Detection of Heptafluoroisobutyronitrile (C4F7N) in a C4F7N–Carbon Dioxide (CO2) Gas Mixture

2019 ◽  
Vol 73 (8) ◽  
pp. 917-926 ◽  
Author(s):  
Yin Zhang ◽  
Xiaoxing Zhang ◽  
Chang Liu ◽  
Yi Li ◽  
Zhaolun Cui ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Sulfur Hexafluoride ◽  
Detection System ◽  
Spectral Characteristics ◽  
Uv Absorption ◽  
Quantitative Detection ◽  
Gas Mixture ◽  
Uv Absorption Spectroscopy

As an alternative to sulfur hexafluoride (SF6) with great potential for application, heptafluoroisobutyronitrile–carbon dioxide (C4F7N–CO2) gas mixture has been applied in various gas-insulated equipment. The insulation performance of the gas mixture is closely related to the mixing ratio. Therefore, accurate quantification of C4F7N in the C4F7N–CO2 gas mixture has very important engineering significance. At present, there are few reports on the rapid quantitative detection of the concentration of C4F7N in the gas mixture. In this paper, a rapid analytical method for C4F7N concentration based on ultraviolet (UV) absorption spectroscopy is constructed. The UV spectral characteristics of C4F7N molecules are calculated by density functional theory. The appropriate bands that can be detected are determined by analyzing the calculated results. A concentration detection system of C4F7N based on UV absorption spectroscopy is built. Through analysis of the calculated results and experimental results, a quantitative detection method of C4F7N in the C4F7N/CO2 gas mixture is determined. The method can achieve accurate detection of the concentration of the gas mixture in the conventional application range (including 4–10% C4F7N). The coefficient of the determination R2 of the concentration inversion curve reaches 0.999 and the inversion error ratio does not exceed 5%. The related research results provide an important reference for the engineering application of the gas mixture.

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