Kinetic analysis of dual impellers on methane hydrate formation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sotirios Nik Longinos ◽  
Mahmut Parlaktuna
Keyword(s):  
Power Consumption ◽  
Kinetic Analysis ◽  
Induction Time ◽  
Methane Hydrate ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Mixed Flow ◽  
Pitched Blade Turbine ◽  
Decline Rate

Abstract This study investigates the effects of types of impellers and baffles on methane hydrate formation. Induction time, water conversion to hydrates (hydrate yield), hydrate formation rate and hydrate productivity are components that were estimated. The initial hydrate formation rate is generally higher with the use of Ruston turbine (RT) with higher values 28.93 × 10−8 mol/s in RT/RT with full baffle (FB) experiment, but the decline rate of hydrate formation was also high compared to up-pumping pitched blade turbine (PBTU). Power consumption is higher also in RT/RT and PBT/RT with higher value 392,000 W in PBT/RT with no baffle (NB) experiment compared to PBT/PBT and RT/PBT experiments respectively. Induction time values are higher in RT/RT experiments compared to PBT/PBT ones. Hydrate yield is always smaller when there is no baffle in all four groups of experiments while the higher values exist in experiments with full baffle. It should be noticed that PBT is the same with PBTU, since all experiments with mixed flow have upward trending.

scholarly journals The Effect of Experimental Conditions on Methane (95%)–Propane (5%) Hydrate Formation

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6710
Author(s):  
Sotirios Nik. Longinos ◽  
Mahmut Parlaktuna
Keyword(s):  
Power Consumption ◽  
Separation Factor ◽  
Induction Time ◽  
Hydrate Formation ◽  
Equilibrium Line ◽  
General View ◽  
Experimental Conditions ◽  
Rushton Turbine ◽  
Pitched Blade Turbine

In the present study, the effect of different kinds of impellers with different baffles or no baffle was investigated. Up-pumping pitched blade turbine (PBTU) and Rushton turbine (RT) were the two types of impellers tested. The reactor was equipped with different designs of baffles: full, half and surface baffles or no baffles. Single (PBTU or RT) and dual (PBTU/PBTU or RT/RT) use of impellers with full (FB), half (HB), surface (SB) and no baffle (NB) combinations formed two sets of 16 experiments. There was estimation of rate of hydrate formation, induction time, hydrate productivity, overall power consumption, split fraction and separation factor. In both single and dual impellers, the results showed that RT experiments are better compared to PBTU in rate of hydrate formation. The induction time is almost the same since we are deep in the equilibrium line while hydrate productivity values are higher in PBTU compared to RT experiments. As general view RT experiments consume more energy compared to PBTU experiments.

Effects of Cyclodextrin Solutions on Methane Hydrate Formation

2007 ◽  
Author(s):  
Ryo Nozawa ◽  
Mohammad Ferdows ◽  
Kazuhiko Murakami ◽  
Masahiro Ota
Keyword(s):  
Raman Spectroscopy ◽  
Induction Time ◽  
Methane Hydrate ◽  
Methane Concentration ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Formation Water ◽  
Advanced Method

In this paper, we suggest the advanced method of methane hydrate formation by cyclodextrin solutions. The structures of the methane hydrate were experimentally investigated by Raman spectroscopy. The induction time of the methane hydrate formation becomes by shorter 10–30 times and formation rate become by faster 2–4 times originated in the increased methane concentration of hydrate formation water by adding cyclodextrins. The results by the Raman spectroscopy indicate that the structure I methane hydrate is produced and methane molecules exist in both Large and Small cages.

scholarly journals Examination of behavior of lysine on methane (95%)–propane (5%) hydrate formation by the use of different impellers

2021 ◽  
Vol 11 (4) ◽  
pp. 1823-1831
Author(s):  
Sotirios Nik. Longinos ◽  
Mahmut Parlaktuna
Keyword(s):  
Amino Acid ◽  
Power Consumption ◽  
Induction Time ◽  
Radial Flow ◽  
Pure Water ◽  
Hydrate Formation ◽  
Hydrodynamic Behavior ◽  
Mixed Flow ◽  
Time Rate ◽  
Flow Experiments

AbstractHydrate formation characteristics and hydrodynamic behavior have been investigated for mixture of methane–propane hydrate formation with pure water and with the amino acid of lysine 1.5 wt% at 24.5 bars and 2 °C. There were total 12 experiments with full and no baffle estimating the induction time, rate of hydrate formation, hydrate productivity and power consumption. The outcomes showed that radial flow experiments with radial flow have better behavior compared to mixed flow ones due to better interaction between gas and liquid. Furthermore, lysine experiments formed hydrates more quickly compared to pure water experiments showing that lysine functions as promoter and not as inhibitor. RT experiments consume more energy compared to PBT ones, while induction time is always smaller in RT experiments compared to PBT ones.

scholarly journals Effect of three representative surfactants on methane hydrate formation rate and induction time

2017 ◽  
Vol 26 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Mostafa keshavarz Moraveji ◽  
Ahmadreza Ghaffarkhah ◽  
Arash Sadeghi
Keyword(s):  
Induction Time ◽  
Methane Hydrate ◽  
Formation Rate ◽  
Hydrate Formation

Experimental Investigation of Methane Hydrate Formation in the Carboxmethylcellulose (CMC) Aqueous Solution

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1042-1056 ◽  
Author(s):  
Weiqi Fu ◽  
Zhiyuan Wang ◽  
Litao Chen ◽  
Baojiang Sun
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Gas Hydrates ◽  
Methane Hydrate ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Semiempirical Model ◽  
Stirred Reactor ◽  
Proposed Model ◽  
Wellbore Pressure

Summary In the development of deepwater crude oil, gas, and gas hydrates, hydrate formation during drilling operations becomes a crucial problem for flow assurance and wellbore pressure management. To study the characteristics of methane hydrate formation in the drilling fluid, the experiments of the methane hydrate formation in water with carboxmethylcellulose (CMC) additive are performed in a horizontal flow loop under flow velocity from 1.32 to 1.60 m/s and CMC concentration from 0.2 to 0.5 wt%. The flow pattern is observed as bubbly flow in experiments. The experiments indicate that the increase of CMC concentration impedes the hydrate formation while the increase of liquid velocity enhances formation rates. In the stirred reactor, the hydrate formation rate generally decreases as the subcooling condition decreases. However, in this work, with the subcooling condition continuously decreasing, hydrate formation rate follows a “U” shaped trend—initially decreasing, then leveling out and finally increasing. It is because the hydrate formation rate in this work is influenced by multiple factors, such as hydrate shell formation, fracturing, sloughing, and bubble breaking up, which has more complicated mass transfer procedure than that in the stirred reactor. A semiempirical model that is based on the mass transfer mechanism is developed for current experimental conditions, and can be used to predict the formation rates of gas hydrates in the non-Newtonian fluid by replacing corresponding correlations. The rheological experiments are performed to obtain the rheological model of the CMC aqueous solution for the proposed model. The overall hydrate formation coefficient in the proposed model is correlated with experimental data. The hydrate formation model is verified and the predicted quantity of gas hydrates has a discrepancy less than 10%.

scholarly journals Geomechanical effects of carbon sequestration as CO2 hydrates and CO2-N2 hydrates on host submarine sediments

2020 ◽  
Vol 205 ◽  
pp. 11003
Author(s):  
Shuman Yu ◽  
Shun Uchida
Keyword(s):  
Carbon Sequestration ◽  
Methane Hydrate ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Small Deformation ◽  
Storage Efficiency ◽  
The Past ◽  
Single Well ◽  
And Storage ◽  
Hydrate Formation Process

Over the past 10 years, more than 300 trillion kg of carbon dioxide (CO2) have been emitted into the atmosphere, deemed responsible for climate change. The capture and storage of CO2 has been therefore attracting research interests globally. CO2 injection in submarine sediments can provide a way of CO2 sequestration as solid hydrates in sediments by reacting with pore water. However, CO2 hydrate formation may occur relatively fast, resulting decreasing CO2 injectivity. In response, nitrogen (N2) addition has been suggested to prevent potential blockage through slower CO2-N2 hydrate formation process. Although there have been studies to explore this technique in methane hydrate recovery, little attention is paid to CO2 storage efficiency and geomechanical responses of host marine sediments. To better understand carbon sequestration efficiency via hydrate formation and related sediment geomechanical behaviour, this study presents numerical simulations for single well injection of pure CO2 and CO2-N2 mixture into submarine sediments. The results show that CO2-N2 mixture injection improves the efficiency of CO2 storage while maintaining relatively small deformation, which highlights the importance of injectivity and hydrate formation rate for CO2 storage as solid hydrates in submarine sediments.

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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