Influence of Gas Supply Mode on CO2 Hydrate Formation in Water Spraying Reactor

2011 ◽  
Vol 236-238 ◽  
pp. 556-561 ◽  
Author(s):  
Ying Ming Xie ◽  
Dao Ping Liu ◽  
Ni Liu ◽  
Ying Xia Qi
Keyword(s):  
Heat Transfer ◽  
Driving Force ◽  
Initial Temperature ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Water Spray ◽  
Gas Hydrate Formation ◽  
Gas Consumption ◽  
Supply Mode ◽  
Gas Supply

In order to study the influence of gas supply modes on CO2 hydrate formation characteristics, a specific water spray gas hydrate formation apparatus was designed. The gas consumption and temperature variation in the process of CO2 hydrate formation under continuous and oscillating gas supply modes were researched. The experimental results showed that hydrate formation rate in the oscillating gas supply mode was greater than in the continuous gas supply mode, which indicates mass transfer driving force caused by disturbance in oscillating gas supply mode is larger than that of continuous gas supply mode. Additionally, under the same initial pressures and the same gas supplying mode, the lower the initial temperature, the larger the heat transfer drive force, and the faster the hydrate formation rate.

scholarly journals Investigation on Gas Hydrates Formation and Dissociation in Multiphase Gas Dominant Transmission Pipelines

2020 ◽  
Vol 10 (15) ◽  
pp. 5052 ◽  
Author(s):  
Sayani Jai Krishna Sahith ◽  
Srinivasa Rao Pedapati ◽  
Bhajan Lal
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Rate ◽  
Water System ◽  
Hydrate Formation ◽  
Multiphase System ◽  
Gas Hydrate Formation ◽  
Water Cut

In this work, a gas hydrate formation and dissociation study was performed on two multiphase pipeline systems containing gasoline, CO2, water, and crude oil, CO2, water, in the pressure range of 2.5–3.5 MPa with fixed water cut as 15% using gas hydrate rocking cell equipment. The system has 10, 15 and 20 wt.% concentrations of gasoline and crude oil, respectively. From the obtained hydrate-liquid-vapor-equilibrium (HLVE) data, the phase diagrams for the system are constructed and analyzed to represent the phase behavior in the multiphase pipelines. Similarly, induction time and rate of gas hydrate formation studies were performed for gasoline, CO2, and water, and crude oil, CO2, water system. From the evaluation of phase behavior based on the HLVE curve, the multiphase system with gasoline exhibits an inhibition in gas hydrates formation, as the HLVE curve shifts towards the lower temperature and higher-pressure region. The multiphase system containing the crude oil system shows a promotion of gas hydrates formation, as the HLVE curve shifted towards the higher temperature and lower pressure. Similarly, the kinetics of hydrate formation of gas hydrates in the gasoline system is slow. At the same time, crude oil has a rapid gas hydrate formation rate.

scholarly journals Thermodynamic Features of the Intensive Formation of Hydrocarbon Hydrates

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3396
Author(s):  
Anatoliy M. Pavlenko
Keyword(s):  
Gas Hydrate ◽  
Formation Rate ◽  
Phase Interface ◽  
Boundary Surface ◽  
Hydrate Formation ◽  
Water Medium ◽  
Gas Temperature ◽  
Mixing Processes ◽  
Gas Hydrate Formation ◽  
Bubble Sizes

This paper presents the results of a study on the influence of pressure and temperature of the gas–water medium on the process of hydrocarbon gas hydrate formation occurring at the phase interface. Herein, a mathematical model is proposed to determine the optimum ratios of pressure, gas temperatures, water, and gas bubble sizes in the bubbling, gas ejection, or mixing processes. As a result of our work, we determined that gas hydrate in these processes is formed at the gas–water interface, that is, on the boundary surface of gas bubbles. Moreover, there is a gas temperature range where the hydrate formation rate reaches its maximum. These study findings can be used to optimize various technological processes associated with the production of gas hydrates in the industry.

Research Progress on the Driving Force of Gas Hydrate Formation

2012 ◽  
Vol 616-618 ◽  
pp. 902-906 ◽  
Author(s):  
Chun Long Wang ◽  
Xue Min Zhang ◽  
Jin Ping Li ◽  
Lin Jun Wang ◽  
Liang Jiao
Keyword(s):  
Growth Rate ◽  
Gas Hydrate ◽  
Induction Time ◽  
Driving Force ◽  
Hydrate Formation ◽  
Research Direction ◽  
Research Progress ◽  
Force Model ◽  
Hydration Reaction ◽  
Gas Hydrate Formation

Predicting the driving force accurately is the key process to hydrate nucleating and growing of hydration reaction. The nucleating and growing process of hydrate is relevant to temperature, pressure and component of reactant, and the property of reaction tank and intermiscibility of reactant have notable effect on the formation process of hydrate with its nucleating position, the induction time, growth rate and hydration rate. However, the present driving force model of hydrate cannot predict nucleating area, induction time, growth rate and the reaction limit, and also can't explain the influence of some factors such as cooling rate, temperature disturbance and inlet way on the hydration reaction, it is uncertain of the process to gas hydrate nucleation. We introduced some driving force models, analyzed their merits and demerits, and looked into the distance of research direction to driving force in the future.

scholarly journals Separation Process of Nonpolar Gas Hydrate in Food Solution under High Pressure Apparatus

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yohanes Aris Purwanto ◽  
Seiichi Oshita ◽  
Yasuhisa Seo ◽  
Yoshinori Kawagoe
Keyword(s):  
High Pressure ◽  
Gas Hydrate ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Separation Process ◽  
Liquid Food ◽  
Screen Size ◽  
Solubility In Water ◽  
Gas Hydrate Formation ◽  
Inner Diameter

Separation process of nonpolar gas hydrate formation in liquid food was experimentally studied under high pressure container. Xenon (Xe) gas was selected as hydrate forming gas and coffee solution was used as a sample of liquid food. The high-pressure stainless steel container having the inner diameter of 60 mm and the volume of 700 mL with a U-shaped stirrer was designed to carry out this experiment. A temperature of 9.0°C and Xe partial pressure of 0.9 MPa were set as a given condition. The experiment was designed to examine the effect of steel screen size, formation rate, temperature condition, and amount of Xe gas dissolving in the solution on the separation process which was indicated by concentration efficiency. Screen size of 200 and 280 mesh resulted in higher concentration efficiency than that of 100 mesh. The higher stirring rate caused the higher formation rate of Xe hydrate and created the smaller Xe hydrate crystals. At the condition giving the same solubility in water, temperature of 14.8°C resulted in lower concentration efficiency than 9.0°C. The increase in the amount of Xe gas dissolving in coffee solution caused the concentration efficiency to decrease; however, the concentration ratio between the final and initial concentration of the solution increased.

Thermal Shock Experiment and Simulation of Ceramic/Metal Gradient Thermal Barrier Coating

2007 ◽  
Vol 336-338 ◽  
pp. 1818-1822
Author(s):  
Jin Sheng Xiao ◽  
Kun Liu ◽  
Wen Hua Zhao ◽  
Wei Biao Fu
Keyword(s):  
Heat Transfer ◽  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Thermal Stresses ◽  
Initial Temperature ◽  
Thermal Barrier ◽  
Water Spray ◽  
Barrier Coating ◽  
Shock Experiment ◽  
Two Stages

A thermal shock experiment is designed to explore the thermal shock properties of ceramic/metal gradient thermal barrier coating. The specimens are heated up by oxygen-acetylene flame and cooled by water spray. The experiment procedure includes two stages, heating the specimen from the initial temperature 30°C for 40s, and then cooling for 20s. The heat transfer and the associated thermal stresses produced during the thermal shock procedure are simulated by finite element method. Experimental results indicated that the specimen of gradient coating behaves better in thermal shock experiments, which agree with the results of simulation.

Simulation of Gas-Hydrate Slurry Stratified Flow With Inward and Outward Hydrate Growth Model

2016 ◽  
Author(s):  
Bohui Shi ◽  
Yang Liu ◽  
Lin Ding ◽  
Xiaofang Lv ◽  
Jing Gong
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Shell Model ◽  
Gas Hydrate ◽  
Hydrodynamic Model ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Phase Flow ◽  
Two Phase

The topic of hydrate formation and blocking in offshore petroleum industry has attracted more and more attentions, which is known as one of the flow assurance issues. A new technology has been proposed to avoid the occurrence of hydrate blockage in multiphase transportation system, which is hydrate slurry flow technology, also named as cold flow technology. The low dosage hydrate inhibitor of anti-agglomerate was added into the flow systems to allow hydrate formation in the liquid phase while it prevented the aggregation of hydrate particles. Thus these particles were evacuated with the liquid phase as pseudo-fluid like slurry. In this work, an inward and outward hydrate growth shell model coupled with two phase flow hydrodynamic model was applied to investigate the characteristics of gas-hydrate slurry stratified flow. The inward and outward hydrate growth shell model considered the kinetics, mass transfer and heat transfer process of hydrate formation, which could predict the hydrate formation rate and the released heat. The two phase flow hydrodynamic model included mass, momentum and energy equations. A case for an inclined pipeline was simulated using the combined models. The results showed that once the kinetic requirements for hydrate crystallization was satisfied, hydrates would form quickly at the initial stage and then hydrate formation rate would decrease obviously due to the limitation of mass transfer and heat transfer. Meanwhile, the flow characteristics, such as the liquid holdup and pressure drop, were predicted by the model, which also provided an acceptable results about the state of hydrates (onset time of formation, formation rate, volume fraction, etc.) in multiphase system for the operation engineers in the field. The key parameters of the inward and outward hydrate growth shell model were determined by referring to the literatures. To investigate the reliability and influence of these set values on the results, a sensitivity analysis of the key parameters of the shell model was implemented. Further works should be done, such as the flow mechanism in other flow regimes as well as the influence of particle aggregation.

Formation Kinetics and Self-Preservation of CO2 Hydrates in the Presence of Carboxylated Multiwall Carbon Nanotubes

2021 ◽  
Author(s):  
Khalik Mohamad Sabil ◽  
Omar Nashed ◽  
Bhajan Lal ◽  
Khor Siak Foo
Keyword(s):  
Gas Hydrate ◽  
Induction Time ◽  
Completion Time ◽  
Formation Rate ◽  
Sodium Dodecyl ◽  
Hydrate Formation ◽  
Significant Finding ◽  
Formation Kinetic ◽  
Gas Hydrate Formation ◽  
The Impact

Abstract Nanofluids are known of having the capability to increase heat and mass transfer and their suitability to be used as kinetic gas hydrate promoters have been recently investigated. They have favorable properties such as high thermal conductivity, large surface area, recyclable, ecofriendly, and relatively cheap that are favorable for kinetic gas hydrate promoters. However, the nanomaterials face challenges related to their stability in the base fluid. Therefore, it is crucial to investigate the impact of surfactant free nanofluid on hydrate formation and dissociation kinetics. In this work, COOH-MWCNT suspended in water is used to study the effect of surfactant free nanofluid on CO2 hydrates formation kinetic and stability. Kinetic study on CO2 hydrates formation as well as self-preservation are conducted in a stirred tank reactor. The kinetic experiments are carried out at 2.7 MPa and 274.15 K. The induction time, initial gas consumption rate, half-completion time t50, semi completion time t95 are measured to evaluate the effect of COOH-MWCNT. Furthermore, the dissociation rate was calculated to assess the impact of COOH-MWCNT on self-preservation at 271.15 K and atmospheric pressure. The results are compared with that of sodium dodecyl sulphate (SDS). The study of CO2 hydrates formation kinetic shows that the induction time is not affected by COOH-MWCNT. The impact of nanofluid is more pronounced during the hydrate growth. The initial formation rate is the highest at 0.01 wt% of COOH-MWCNT whereas 0.01 and 0.03 wt% shows the same and shortest t50. However, t95 found to be decreased with increasing the concentration. The effect of COOH-MWCNT is attributed to the strong functional group. Self-preservation results shows CO2 hydrates are less stable in the presence of COOH-MWCNT. The result of this work may provide significant finding that can be used to developed kinetic gas hydrate promoter based on nanofluid that work better than SDS to eliminate gas hydrate formation in oil and gas pipeline.

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