scholarly journals Thermodynamic Modeling Of Electrolytic Solutions of Ionic Liquids for Gas Hydrates Inhibition Applications

Author(s):  
Ali Qasim ◽  
Jeremy Heurtas ◽  
Muhammad Saad Khan ◽  
Bhajan Lal ◽  
Azmi Mohammad Shariff ◽  
...  

The formation of hydrates in oil and gas transmission pipelines can cause blockage inside them and disrupt the normal flow. It may cause safety problems along with economic loss. To avoid these problems, it is necessary to have knowledge about gas hydrate formation. In this regard, hydrate liquid vapor equilibrium (HLVE) modeling can prove to be of significance as it predicts the phenomenon accurately. Dickens and Quinby-Hunt model is used to predict HLVE points. The experimental data has been obtained from open literature concerning inhibition of gas hydrates. The electrolytic binary solution mixtures of ionic liquids and quaternary ammonium salts (QAS) with commercial hydrate inhibitors have been taken into consideration. Methanol and mono ethylene glycol (MEG) are commercially used inhibitors. The gases forming hydrates include CO2, CH4 and mixed gas (CO2/CH4/N2). The experimental results are compared with the results obtained through modeling. The results show the applicability of the model as in case of QAS+MEG solution mixture hydrates with CO2, it shows a good fit. The HLVE findings by model for CH4 hydrates with EMIM-Cl+MEG solution mixture showed an average absolute error of less than 1% which is acceptable. The binary solution mixtures of NaCl+MEG, NaCl+MeOH and CaCl2+MeOH with tertiary gas mixture rich in CO2 were also modeled to find and compare the HLVE points from literature. It is found that the selected model is more suitable to be used in low pressure conditions and at high pressure, average absolute error (AAE) between experimental and modeling values is also high. It shows the suitability of the model and it can be further used in case of ionic compounds to predict hydrate inhibition behavior.

Author(s):  
Ajay Mandal ◽  
Sukumar Laik

Gas hydrates are now gaining importance in oil and gas industries because they are considered a future source of energy and a means for the transport of natural gas. On the other hand gas hydrates create problems by plugging the pipelines during transportation. Obviously, predicting the conditions in which hydrates are formed would be valuable. In the present study, experiments were performed to observe the conditions, which favor the formation of an ethane gas hydrate. The results of the hydrate formation are elucidated with the help of a conceptual kinetic model. An empirical correlation is developed to predict the rate of formation of the hydrate in terms of the operating and geometric variables of the system. A simple kinetic model based on the dissolved ethane gas is also developed which shows that the hydrate formation follows the first order rate equation.


Author(s):  
Catalin Teodoriu ◽  
Gioia Falcone ◽  
Amodu Afolabi

Gas hydrates are ice-like crystalline systems made of water and methane that are stable under high pressure and low temperature conditions. Gas hydrates have been identified as strategic resources and may surpass all known oil and gas reserves combined. However, these resources will become reserves only if the gas contained therein can be produced economically. In the oil and gas industry, gas hydrates may be encountered while drilling sediments of the subsea continental slopes and in the subsurface of permafrost regions. They also represent a flow assurance issue, as they may form in the well and in the flowlines, causing blockages. Deepwater drilling programmes have experienced problems when encountering gas hydrate formations. A major issue is that of phase transition, where gas hydrate goes from a solid state to dissociated gas and water, as there are rapid changes in fluid volumes and pressure. This can cause drilling equipment failure, borehole instability and formation collapse. After dissociation of water and gas, hydrates may be prevented from forming in the well by using appropriate inhibitors in the drilling mud. There is a need to develop fluids specifically for drilling through gas hydrate formations, either to unlock the unconventional reserves trapped in the crystalline gas hydrate structures or to safely reach underlying conventional reserves. To drill wells in a gas hydrate formation, a conductor casing is needed to allow close loop circulation of the mud, if different from seawater. The search for the ideal mud for drilling through gas hydrate formations must start with a review of past experiences worldwide and of the lessons learned. This paper presents a review of the problems encountered while drilling through gas hydrate formations. It identifies the key requirements for drilling fluids, based on the interaction between the drill bit, the drilling fluid and the formation. An evaluation of the environmental risk associated with drilling through gas hydrate formations is also presented.


2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>


2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>


2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3615
Author(s):  
Florian Filarsky ◽  
Julian Wieser ◽  
Heyko Juergen Schultz

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.


2021 ◽  
Vol 3 (144) ◽  
pp. 22-31
Author(s):  
Viktor S. Grigor’yev ◽  
◽  
Il’ya V. Romanov

The ability of gas hydrates to concentrate gas into a solid chelate structure and the properties of self-preservation of gas hydrates at negative temperatures allows us to consider the possibility of developing a method for the utilization of biogas, environmentally safe storage and transportation of biomethane. (Research purpose) The research purpose is in substantiation the technological possibilities of obtaining synthetic mixed gas hydrates of biogas components, their storage and transportation based on the analysis of the existing regularities of the formation of gas hydrates in time, temperature and external pressure. (Materials and methods) The article presents the accumulated results of studies of the process of obtaining artificial hydrates of natural gas and methane- containing gas mixtures at various initial static pressures and temperatures. The object of research to substantiate the parameters of artificial creation of gas hydrates is biogas obtained during anaerobic thermophilic fermentation of organic waste at an existing experimental biogas plant. Mixed feed SK-8 with a humidity of 90-92 percent was used as an organic substrate of constant composition. The composition of biogas was studied using the Optima-7 Biogas gas analyzer. (Results and discussion) The article presents a process model and a technical appearance of an installation for producing gas motor fuel from the biogas of anaerobic digestion of organic waste of the agro-industrial complex. The hydrate formation time depends on the increase in the interfacial surface and the movement of gas bubbles relative to the liquid, which can be regulated by acting on the hydrate formation zone (shock wave, electromagnetic, mechanical, chemical, temperature). (Conclusions) The research results can be used in modeling processes in two-phase media during the formation of gas hydrates and the creation of installations for their production.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1107
Author(s):  
Seong-Pil Kang ◽  
Dongwon Lee ◽  
Jong-Won Lee

Kinetic hydrate inhibitors (KHI) and anti-agglomerants (AA) rather than thermodynamic hydrate inhibitors (THI) are often used for flow assurance in pipelines. This is because they require much lower dosages than thermodynamic inhibitors. Although the hydrate-phase equilibria are not affected, KHI and AA prevent the formed hydrate crystals from growing to a bulky state causing pipeline blockage. However, these KHIs might have huge environmental impact due to leakages from the pipelines. In this study, two biodegradable AA candidates from natural sources (that is, lecithin and lanolin) are proposed and their performances are evaluated by comparing them with and without a conventional AA (Span 80, sorbitan monooleate). At 30% and 50% water cut, the addition of AA materials was found to enhance the flow characteristics substantially in pipelines and hardly affected the maximum value of the rotational torque, respectively. Considering the cost-effective and environmental advantages of the suggested AA candidates over a conventional AA such as Span 80, the materials are thought to have potential viability for practical operation of oil and gas pipelines. However, additional investigations will be done to clarify the optimum amounts and the action mechanisms of the suggested AAs.


2020 ◽  
Vol 10 (15) ◽  
pp. 5052 ◽  
Author(s):  
Sayani Jai Krishna Sahith ◽  
Srinivasa Rao Pedapati ◽  
Bhajan Lal

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.


Sign in / Sign up

Export Citation Format

Share Document