Stability Of Condensate Research Articles

Исследование влияния узких фракций дисульфидного масла на степень растворения асфальтосмолопарафиновых отложений на теплообменном оборудовании Оренбургского газоперерабатывающего завода

Currently, there are a number of unsolved problems in oil and gas processing, one of which is the search for an effective and relatively cheap solvent for asphalt-resin-paraffin deposits. This article discusses the features of asphalt-resin-paraffin deposits, which are a complex structured system with a pronounced core of asphaltenes and a sorption-solvation layer of oil resins (CCE), and features of the asphalt-resinous substances (DIA), which are heterocyclic compounds of complex hybrid structure, in which includes nitrogen, sulfur, oxygen and metals. In the course of the study, the choice of optimal methods for controlling asphalt-resin-paraffin deposits was carried out and the effectiveness of various methods depends on many factors, in particular, on the properties of oil or gas condensate, the mode of operation of the installation, surface roughness and equipment design. The article describes the process of removing already deposited asphalt-resin-paraffin deposits using the most promising chemical method. Both individual solvents and multicomponent compositions are used as remover reagents. In some cases, to increase the efficiency of the solvent is heated or it is served together with the steam. In the process of selecting the solvent, you need to consider that each type of oil will be suitable for a certain type of reagent, there are no universal solvents. This article describes the process of removing asphalt-resin-paraffin deposits, where the supply of reagents occurs through special devices. Various solvents were selected, in the process of research their properties, features, characteristics were studied and a practical study of its declared characteristics and determination of its effectiveness were carried out. As part of this study, the fractionation of disulfide oil was studied according to GOST 2177-99 «Oil products. Methods for determining the fractional composition» and studied the effect of individual fractions on the sediments taken from the walls and tube bundles of heat exchange equipment of the condensate stabilization plants of the Orenburg Gas Processing Plant. The results of the experiments helped to calculate the effectiveness of the solvents taken.

Energy efficiency to increase production and quality of products in industrial processes: case study oil and gas processing center

The emphasis of this paper is to show the existence of some non-energy benefits that can be taken into account in an energy efficiency investment aimed to reduce energy consumption and increase production and product quality in an oil and gas processing center (OGPC) in Mexico. The function of OGPC is to separate crude oil, gas, and saltwater coming from marine and terrestrial oil fields. Traditionally, application of process energy integration techniques has been aimed to reduce energy consumption associated with heating and cooling services. In this paper, the process energy integration (standard pinch analysis) of an OGPC shows the possibility of reducing natural gas and electricity consumption by 75 % and 98 %, respectively. However, the novel aspect of this work is the identifications and use of some waste heat streams available in processes to reduce energy consumption, and more importantly couple them with some non-energy-related benefits to produce massive economical savings. For example, by allowing an improvement in the quality of heavy crude oil for exportation (reduction in salt content), an increased sale price of 0.6 USD/barrel is achieved, rising profit to 156.88 MMUSD/year. Additional economic benefits came from the restauration of the production of 3,711 barrel of naphtha per day (33.86 MMUSD/year), by solving security issues related to the use of direct-fire heaters in the condensate stabilization plant.

Quantum Vacuum: The Structure of Empty Space–Time and Quintessence with Gauge Symmetry Group SU(2) ⊗ U(1)

We consider the formation of structured and massless particles with spin 1, by using the Yang–Mills-like stochastic equations system for the group symmetry S U ( 2 ) ⊗ U ( 1 ) without taking into account the nonlinear term characterizing self-action. We prove that, in the first phase of relaxation, as a result of multi-scale random fluctuations of quantum fields, massless particles with spin 1, further referred as hions, are generated in the form of statistically stable quantized structures, which are localized on 2D topological manifolds. We also study the wave state and the geometrical structure of the hion when as a free particle and, accordingly, while it interacts with a random environment becoming a quasi-particle with a finite lifetime. In the second phase of relaxation, the vector boson makes spontaneous transitions to other massless and mass states. The problem of entanglement of two hions with opposite projections of the spins + 1 and − 1 and the formation of a scalar zero-spin boson are also thoroughly studied. We analyze the properties of the scalar field and show that it corresponds to the Bose–Einstein (BE) condensate. The scalar boson decay problems, as well as a number of features characterizing the stability of BE condensate, are also discussed. Then, we report on the structure of empty space–time in the context of new properties of the quantum vacuum, implying on the existence of a natural quantum computer with complicated logic, which manifests in the form of dark energy. The possibilities of space–time engineering are also discussed.

Non-isobaric Thermal Instability

Abstract Multiphase media have very complex structure and evolution. Accurate numerical simulations are necessary to make advances in our understanding of this rich physics. Because simulations can capture both the linear and nonlinear evolution of perturbations with a relatively wide range of sizes, it is important to thoroughly understand the stability of condensation and acoustic modes between the two extreme wavelength limits of isobaric and isochoric instability as identified by Field. Partially motivated by a recent suggestion that large non-isobaric clouds can “shatter” into tiny cloudlets, we revisit the linear theory to survey all possible regimes of thermal instability. We uncover seven regimes in total, one of which allows three unstable condensation modes. Using the code Athena++, we determine the numerical requirements to properly evolve small amplitude perturbations of the entropy mode into the nonlinear regime. Our 1D numerical simulations demonstrate that for a typical AGN cooling function, the nonlinear evolution of a single eigenmode in an isobarically unstable plasma involves increasingly larger amplitude oscillations in cloud size, temperature, and density as the wavelength increases. Such oscillations are the hallmark behavior of non-isobaric multiphase gas dynamics and may be observable as correlations between changes in brightness and the associated periodic redshifts and blueshifts in systems that can be spatially resolved. Intriguingly, we discuss regimes and derive characteristic cloud sizes for which the saturation process giving rise to these oscillations can be so energetic that the cloud may indeed break apart. However, we dub this process “splattering” instead of “shattering,” as it is a different fragmentation mechanism that is triggered when the cloud suddenly “lands” on the stable cold branch of the equilibrium curve.

Energy and exergy analysis of intensified condensate stabilization unit with water draw pan

An industrial condensate stabilizer unit is simulated with HYSYS 3.1 software when the excessive water is present on the trays. Effects of reboiler temperature, excess water flow rate, and incoming stream temperature on the Reid vapor pressure (RVP), temperature distribution along the column and impurity concentrations along the stabilization column, as well as, energy usage are studied. In addition, the optimal location for the water draw tray for the condensate stabilizer column is found. It is observed that the presence of water draw pan in the column leads to about 15% and 28% reduction, respectively, in the reboiler and the compressor duties compared to the industrial case without water draw pan. For the optimal case, 73% of excess water is recovered from the water draw pan. The presence of the water draw pan in the column also results in lower amount of impurities and higher heating value in the off-gas stream. Finally, the column with the water draw pan shows higher exergy efficiency of about 81% in comparison with the column without water draw pan (with exergy efficiency of about 72%).

Risk assessment of naturally occurring radioactive materials (NORM) in the hydrocarbon sludge extracted from the south pars gas field in Iran

Natural radionuclides are always present in soil, water, and in particular in materials extracted from the depths of the earth. The accumulation of natural radionuclides and the increase in their radioactivity to excessive levels will lead to health hazards and environmental damages. Therefore, carrying out studies, evaluations and risk assessments in industries with the possibility of excessive accumulation of these materials in their various processes is inevitable to protect occupational health of employees and stakeholders and prevent the pollution of environmental resources including soil, water and air. Oil and gas fields are among the most prepared areas in this regard. Iran is one of the largest owners and producers of huge oil and gas resources in the world. The great concentration of hydrocarbon reservoir extraction and production facilities in some parts of the country, and the presence of a large number of oil & gas organizations employees in these areas, necessitate such studies. For this reason, one of the South Pars gas field refineries located in Pars special economic energy zone, Assaluyeh, Iran, was selected to investigate the concentration of radioactivity of hydrocarbon sludge and soil and the related hazards indices (potential hazards). The obtained results showed that the concentrated sludge in the condensate pre-flash drum of the condensate stabilization unit and some of heat exchangers had higher than normal radioactivity levels. Furthermore, health and environmental risks were assessed and the results indicate that there are high risks in some activities and environmental aspects that it is necessary to consider controls to reduce them to acceptable levels.

Controlling stability of Bose-Einstein condensation of interacting magnons in an antiferromagnet by an external magnetic field

We propose a mechanism for destabilizing or stabilizing Bose-Einstein condensation (BEC) of interacting magnons in an antiferromagnet. We study how the interaction between magnons affects the magnon BEC in a two-sublattice antiferromagnet without and with an external magnetic field. We show that in the absence of the magnetic field the magnon BEC is destabilized by the attractive interband interaction, which is larger than the repulsive intraband interaction. We also show that in the presence of the magnetic field the magnon BEC is stabilized only if the magnetic field is large enough to make the intraband interaction larger than the interband interaction. Our results provide the first step for understanding the interaction effects on the magnon BEC in antiferromagnets and may open interaction physics of multicomponent BEC of magnons in magnets.

Localization Study of a Cold Atom BEC in Two-Dimensional Bessel Optical Lattices

In order to investigate the stability and dynamics properties of a cold atom Bose-Einstein Condensate (BEC) in two-dimensional Bessel optical lattices, the stability condition of the system is analyzed and the corresponding Gross-pitaevskii equation (GPE) is solved in this paper by time-dependent variational method and numerical simulation. Firstly, the Euler-Lagrange equation containing the parameters describing the system stability and the effective potential energy needed by the variational analysis method to analyze the system stability is obtained by using the adjustable exponent Gaussian trial wave function. Secondly, according to the analytical solution of Euler-Lagrange equation and the local minimum value of potential energy, the stability condition of the system is further illuminated. Finally, the influence mechanism of these parameters on the local dynamics is revealed by solving the corresponding GPE with numerical method.

Stabilization of trapless dipolar Bose-Einstein condensates by temporal modulation of the contact interaction

We theoretically study the stability of a trapless dipolar Bose-Einstein condensate (BEC) with temporal modulation of short-range contact interaction. For this aim, through both analytical and numerical methods, we solve a Gross-Pitaevskii equation with both constant and oscillatory form of short-range contact interaction along with long-range, nonlocal, dipole-dipole (DD) interaction terms. Using variational method, we discuss the stability of the trapless dipolar BEC with presence and absence of both constant and oscillatory contact interactions. We show that the oscillatory contact interaction prevents the collapse of the trapless dipolar BEC. We confirm the analytical prediction through numerical simulations. We have also studied the collective excitations in the system induced by the effective potential due to oscillating interaction.

Decay of ultralight axion condensates

Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses m ∼ 10−22 eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

THE ELECTROMAGNETIC FIELDS EFFECT ON CHAOTIC DYNAMICS OF CARDIOVASCULAR SYSTEM PARAMETERS OF WORKERS OF OIL AND GAS INDUSTRY

The motion of state vector of cardiovascular system in females working on Surgut condensate stabilization plant was studied in five-dimensional phase space of states. The parameters xi of cardiovascular system in four groups of women varied within the range of VG - bounding volumes of the phase space of states, which was defined as quasi-attractor. The volumes VG were measured and compared in women of different age, affected and not affected by human-made electromagnetic fields of industrial frequency, which allowed establishing the principal differences in the dynamics of VG. In particular, women, both younger and older age groups underwent stress effect of electromagnetic fields of industrial frequency. This led to breakdown in volume of quasi-attractors in phase plane of vector (x1, x2)T where x1 - duration of cardiointervals, and x2 = dx1/dt - rate of change of x1. In fact, electromagnetic fields became stress agents for human's cardiovascular system in the North of Russian. This is shown in the framework of quasi-attractors for cardio of two groups of women. Comparison of these four groups according to the parameters of quasi-attractors showed differences though statistical differences were not significant on a number of xi parameters of whole the body state vector x (f) of person's organism living in the special northern conditions.

Optimal dynamic logistic planning of the supply chain of a gas condensate stabilization plant

The management of the economy and the mathematical formulation of the problem of optimal dynamic (multiperiod) logistic planning of the initial and modified supply chain of a gas condensate stabilization plant has been suggested in the form of a multidimensional mixed-integer linear programming problem. An interactive procedure for solving this problem has been developed using the Oracle Strategic Network Optimization software suite. Optimal logistic planning parameters have been calculated for the new modified supply chain with the commissioning of a new plant for processing a wide fraction of light hydrocarbons.

Inflaton condensate fragmentation: Analytical conditions and application to α -attractor models

We study the stability of an inflaton condensate in the presence of attractive inflaton self-interactions, in order to determine analytical conditions on the self-interaction couplings under which the condensate undergoes fragmentation. As an application of our results, we consider the stability of the inflaton condensate in $\alpha$-attractor inflation. We show that the stability of the condensate depends upon the value of $\alpha$. For the T-model with $n = 1$, we find that it is unstable for $\alpha \lesssim 10^{-4}$. In this case it is expected that inflation will be followed by an oscillon-dominated era.

Stability and Metastability of Trapless Bose-Einstein Condensates and Quantum Liquids

AbstractVarious kinds of Bose-Einstein condensates are considered, which evolve without any geometric constraints or external trap potentials including gravitational. For studies of their collective oscillations and stability, including the metastability and macroscopic tunneling phenomena, both the variational approach and the Vakhitov-Kolokolov (VK) criterion are employed; calculations are done for condensates of an arbitrary spatial dimension. It is determined that that the trapless condensate described by the logarithmic wave equation is essentially stable, regardless of its dimensionality, while the trapless condensates described by wave equations of a polynomial type with respect to the wavefunction, such as the Gross-Pitaevskii (cubic), cubic-quintic, and so on, are at best metastable. This means that trapless “polynomial” condensates are unstable against spontaneous delocalization caused by fluctuations of their width, density and energy, leading to a finite lifetime.

Spin superfluidity and spin waves in YIG films

Recently it was suggested that stationary spin supercurrents (spin superfluidity) are possible in the magnon condensate observed in yttrium-iron-garnet (YIG) magnetic films under strong external pumping. Here we analyze this suggestion. From topology of the equilibrium order parameter in YIG one must not expect energetic barriers making spin supercurrents metastable. However some small barriers of dynamical origin are possible nevertheless. The critical phase gradient (analog of the Landau critical velocity in superfluids) is proportional to intensity of the coherent spin wave (number of condensed magnons). The conclusion is that although spin superfluidity in YIG films is possible in principle, the published claim of its observation is not justified. The analysis revealed that the widely accepted spin-wave spectrum in YIG films with magnetostatic and exchange interaction required revision. This led to revision of non-linear corrections, which determine stability of the magnon condensate with and without spin supercurrents.

Simulation and optimization of an industrial gas condensate stabilization unit to modify LPG and NGL production with minimizing CO2 emission to the environment

In the present study, a great effort was made to improve the performance of an industrial liquefied petroleum gas (LPG) and natural gas liquid (NGL) production unit in one of the major gas refinery located at Pars special economic zone in Iran. To demonstrate and obtain the optimal condition, the unit was simulated by using a steady-state flowsheet simulator, i.e. Aspen Plus, under different operational conditions. According to the simulation results, the unit was not operational under its optimal conditions due to some defects in the cooling system at top stage of the debutanizer tower (DBT) during hot and humid seasons. Additionally, the vapor pressure of produced LPG and accordingly the amount of its flaring were decreased by reducing the temperature of debutanizer tower at top stages. In the optimization section, the DBT condenser and reboiler heat duty, temperature, and pressure were regulated as adjustable parameters. The simulation results demonstrated that by applying the optimum suggestion in the hot months, the reflux stream temperature was reached about 55°C which caused an efficient increment in LPG production (about 4%) with adjusting the propane component in LPG, based on the standard range as the plant criteria. Moreover, after applying modifications, about 750t of LPG product was saved from flaring during five hot months of the year, which resulted in 360000USD extra annual income for the company. Finally, from environmental point of view, this optimization caused to reduce 81t of CO2 emission to the environment. Therefore, the current investigation must be introduced as a friendly environmentally process.

Attraction-induced dynamical stability of a Bose-Einstein condensate in a nonlinear lattice

We study multiple-period Bloch states of a Bose-Einstein condensate with spatially periodic interactomic interaction. Solving the Gross-Pitaevskii equation for the continuum model, and also using a simplified discrete version of it, we investigate the energy-band structures and the corresponding stability properties. We observe a new "attraction-induced dynamical stability" mechanism caused by the localization of the density distribution in the attractive domains of the system and the isolation of these higher-density regions. This makes the superfluid stable near the zone boundary, and also enhances the stability of higher-periodic states if the nonlinear interaction strength is sufficiently high.

Lattice distortion inducing electron-hole pair condensation in two dimensional systems

A stability of the electron-hole pair condensation at low temperature has been addressed by involving the coupling of exciton to vibrational degrees of freedom in two-dimensional two-band f – c electron system. By mean of the unrestricted Hartree-Fock approximation, we find a formation of the insulating state typifying an excitonic condensate accompanied by a finite lattice distortion if the exciton-phonon coupling is large enough. As functions of temperature both excitonic condensation order parameter and lattice distortion behave in a same way which manifests the continuous transition in analogy to the superconductivity in the BCS theory. Inspecting to the microscopic properties in momentum space we strongly specify the BCS type of the excitonic condensation driven by the exciton-phonon interaction at low temperature.

Simulation analysis of stripping fractionation process of gas condensate treatment and practical application

Stripping fractionation is posed an advancing and promising process for gas condensate stabilization and desulfurization. Most of H2S, light mercaptan and part of organic sulfur are removed while the condensate is stabilized in same column, reducing the capital investment for conventional condensate treatment process. In terms of this newly designed process, two approaches for raw liquid inlet to a stabilizer were considered, i.e. split-flow and straight-through for comparison purpose between them and their respective scope of application. The whole process was simulated by ASPEN HYSYS software. According to the simulation results in conjunction with the running experience in a natural gas processing plant in Mary, Turkmenistan, the priority of this new process in the field of condensate treatment has been demonstrated, meeting the requirement of Reid Vapour Pressure (RVP) and sulfur concentration restriction. Finally, the spilt-flow approach with the optimal split ratio range from 10% to 30%, was inherently beneficial related to economic aspects in large processing scale case. Also, the economical analysis of split-flow method was involved in detail.

Temperature effects in excitonic condensation driven by the lattice distortion

AbstractThe stability of the excitonic condensation at low temperature driven by a coupling of electrons to vibrational degrees of freedom in a semimetal two‐dimensional electronic system is discussed. In the framework of the unrestricted Hartree–Fock approximation, we derive a set of equations to determine both the excitonic condensate order parameter and lattice displacement self‐consistently. By lowering the temperature, we find a semimetal–insulator transition in the system if the coupling is large enough. The insulating state typifies an excitonic condensation accompanied by a finite lattice distortion. On increasing temperature, both excitonic condensate order parameter and the lattice distortion decrease and then disappear in the same manner. Microscopic analysis in momentum space strongly specifies that the excitonic condensate driven by the lattice distortion favors the BCS type.