Condensable Hydrocarbons Research Articles

On the transition of liquid dispersion states and their physical-thermodynamic nature in the development of gas-condensate reservoirs in depletion mode

While the depletion regime for gas-condensate fields may be more cost-effective, it often results in the loss of hydrocarbon condensate, which is economically more valuable than gas, and leads to the inefficient exploitation of the field in terms of condensate production. Therefore, the development of effective exploitation systems for such fields is essential. Effective exploitation of gas-condensate fields involves achieving maximum hydrocarbon condensate production in addition to maximum gas production. From this aspect, managing the condensate factor of reservoir system during the depletion regime is a critical issue. The article experimentally and theoretically investigates the phase transitions or mutual dispersion occurrences between hydrocarbon liquid and gas mixtures that occur with a decrease in pressure at reservoir temperature during the natural depletion of gas-condensate fields. During the exploitation of gas-condensate fields, it has been observed that even at pressures higher than retrograde condensation pressure, the hydrocarbon system undergoes complex phase transitions, resulting in distinct transition points due to the mutual dispersion of hydrocarbon liquid and gas. Additionally, pVT studies conducted in the laboratory have made it possible to determine the transition points of the reservoir fluid in the “liquid in gas” and vice versa dispersion states. The research has demonstrated that dependance of gas condensate factor on pressure under given isothermal natural conditions more clearly reflects the retrograde and maximum condensation, also dispersion points of the liquid components. It was found that proportionality coefficient between condensate ratio and pressure of gas-condensate system is unique for each production facility under isothermal conditions and characterizes the stability of fluid’s dispersion state. The importance of considering such transition points when designing gas-condensate field development projects has been highlighted.

Mapping of hydrocarbon condensation onset temperature and its sensitivity analysis for Exhaust Gas Recirculation (EGR) cooler

Exhaust Gas Recirculation (EGR) cooling technology is one of the key technologies of the engine to meet the Euro 7 emission standard. Nevertheless, the hydrocarbon (HC) condensation in the cooler leads to uncontrolled thermal-hydraulic performance, and the onset temperature of HC condensation is still debated, which is one of the obstacles to implementing the Euro 7 standard. Here, we first established a database of key parameters (carbon number, concentration, and pressure); then theoretically calculated the onset temperatures of various condensation types (wall condensation, heterogeneous nucleation, and homogeneous nucleation), plotted the entire map and verified its veracity; and finally, elucidated the contribution of each parameter through sensitivity analysis. The results show that (i) HC species are C12 to C25, from 25 to 1717 ppm concentrations, and pressures are from 1 to 4 bar. (ii) The map diagrams for the onset temperature of HC condensation have broad applicability and strong practicality. (iii) The temperature ranges of the onset of wall condensation, heterogeneous nucleation, and homogeneous nucleation are from 4 to 218 °C, from 1 to 209 °C, and from −6 to 195 °C, respectively. (iv) Carbon number has the most significant contribution, followed by HC concentration and pressure. The results can provide a valuable reference for more accurate EGR cooler design and management.

Parameterization of H2SO4 and organic contributions to volatile PM in aircraft plumes at ground idle

ABSTRACT Volatile Particulate Matter (vPM) emissions are challenging to measure and quantify, since they are not present in the condensed form at the engine exit plane and they evolve to first form in the aircraft plume and then continue to grow and change as they mix and dilute in the ambient atmosphere. To better understand the issues associated with the initial formation and growth of vPM, a modeling study has been undertaken to examine several key parameters that affect the formation and properties of the vPM that is created in the initial cooling and dilution of the aircraft exhaust. A modeling tool (Aerosol Dynamic Simulation Code, ADSC) that was developed and enhanced over a series of past research projects supported by NASA, DoD’s SERDP/ESTCP, and FAA was used to perform a parametric analysis of vPM. The parameters of fuel sulfur content (FSC), emitted condensable hydrocarbon (HC) concentrations, and the species profile of the HCs were used to construct a computational matrix that framed a wide range of expected parameter values. This computational matrix was executed for two representative commercial aircraft engines at ground idle and results were obtained for distances of 250 m and 1000 m downstream. From prior results, the most significant vPM emissions occur at the lowest power settings, so an engine power condition of 7% rated thrust was used. A primary goal of the parametric study is to develop an updated vPM modeling methodology and also to help interpret data collected in experimental campaigns. The parameterization proposed here allows the vPM emission composition and particle numbers to be estimated in greater detail than current methods. The aim is to provide additional understanding on how the vPM properties vary with fuel and engine parameters to increase the utility of vPM predictions. Implications: Volatile Particulate Matter (vPM) is an important contribution to the total PM emitted by aviation engines. While vPM is not currently a part of engine emissions certification regulations, vPM is used in aviation environmental impact assessments and for air quality modeling in and around airports. Current methods in use, such as FOA, were developed before many recent advances in experimental data acquisition and in understanding of vPM processes. The parameterization proposed here allows the vPM emission composition and particle numbers to be estimated in greater detail than current methods. These estimates can be used to develop inventories and provide a better estimate of total emission for most aviation engines. Its use in international regulatory tools can inform possible future regulatory actions regarding vPM.

Product characterization and pore structure evolution of a tar-rich coal following pyrolysis under nitrogen, steam/nitrogen, and oxygen/nitrogen atmospheres

Steam and an oxidative medium could be the most promising atmosphere for the in-situ pyrolysis of tar-rich coal. This study investigated the influence of these two atmospheres by comparing product yields, tar properties, and pore evolution characteristics of a tar-rich coal following pyrolysis under nitrogen (N2), steam/nitrogen (steam/N2), and oxygen/nitrogen (O2/N2). Compared with N2 pyrolysis, steam/N2 pyrolysis increased the tar yield by 0.54–1.33 wt% at 350–600 °C; further, O2/N2 pyrolysis increased the tar yield from 0.57 wt% to 3.53 wt% at 350 °C while decreasing this value by 0.31–1.83 wt% at 400–600 °C. At 450 °C and 500 °C, steam addition suppressed the formation of oxygenated compounds, thereby decreasing the O/C ratio of tar from 0.099 and 0.088 to 0.073 and 0.074, respectively. Conversely, O2 introduction presented the oxygen addition of tar by oxidation reactions. Meanwhile, steam inhibited the aromatization of alkanes and the condensation of monocyclic aromatic hydrocarbons (MAHs). By contrast, O2 was able to promote the condensation of phenols and MAHs. At 450 °C, steam/N2 was thought to assist in the cracking of the plastic mass by providing a H2-rich atmosphere, which decreased the pitch content of tar and increased the contents of light fractions. O2/N2 was also beneficial for the formation of light fractions by intensifying the thermal cracking effect. Micro-CT and SEM analysis showed that H2O could promote the formation of micro-sized pores within the coal matrix, decreasing the average pore diameter (APD) from 150.95 μm to 102.67 μm and increasing the average coordination number (ACN) of pores from 6.27 to 8.59. O2 was inclined to enlarge the pyrolysis-induced pore network, which imposed a contrasting effect on APD and ACN parameters. Steam is recommended as the preferred atmosphere for the in-situ pyrolysis of tar-rich coal.

Efficiency of Volatile Corrosion Inhibitors in the Presence of n-Heptane: An Experimental and Molecular Simulation Study

Volatile corrosion inhibitors (VCIs), specifically formulations based on thiols and amines, can be used to mitigate top-of-the-line corrosion (TLC) that arises during the transportation of wet gas through transmission pipelines. Nevertheless, the VCI inhibition efficiency (IE) can be compromised by the presence of condensable hydrocarbon phases. In this research, the IE of two thiol compounds (decanethiol and hexanethiol) and three combinations of VCIs for TLC scenarios, both in the presence and absence of n-heptane, representing a condensing hydrocarbon phase were studied. The results proved the IE of thiols in a water-only condensing environment, with effectiveness increasing with the alkyl tail length. Conversely, in a water/n-heptane co-condensing environment, a reversed trend was observed, where hexanethiol exhibited higher corrosion IE compared to decanethiol. Molecular simulation results indicated a synergistic adsorption behavior when the alkane was of a similar length as the alkyl tails of the inhibitors, leading to the incorporation of alkane molecules with the inhibitor molecules. A mixture of thiols (decanethiol and hexanethiol) and two mixtures of thiol and amines (decanethiol and diethylamine/t-butylamine) were also considered in both water-only and water/n-heptane co-condensing environments. In the presence of n-heptane, only the thiol mixture, featuring molecules with different tail lengths, demonstrated high IE. This behavior was attributed to the superior IE provided by thiol-based molecules with a shorter alkyl tail (hexanethiol) in the presence of n-heptane. Additionally, the results revealed that the mixtures of decanethiol and amines did not enhance corrosion inhibition in the presence of n-heptane within the system.

Molecular Insights of Excessive Water Cut during Cyclic Gas Injection in Liquid-Rich Shale Reservoirs: Contributions of Hydrocarbon Condensation and Water Trapping

Summary In a recent pilot test of cyclic gas injection (huff ‘n’ puff) in a Permian shale reservoir, excessive water product was observed, the reason for which remains unclear. In this work, we analyze the mechanisms of gas huff ‘n’ puff processes using molecular dynamics (MD) simulations and explain the reason for the high water-cut phenomenon. We aim to investigate the hydrocarbon-water-rock interactions during the gas injection as well as production within a shale rock in the pore scale. To mimic the heterogeneous pore structure of the shale rock, we have designed a pore system, including a bulk pore, a pore throat, and a dead-end pore. We simulate the distribution of different fluids during the initial equilibrium stage, the primary depletion stage, and the huff ’n’ puff stage. The results show that an excessive amount of water is trapped by the condensation mechanism in the larger pores during the primary depletion stage. The water is then recovered with the injection of working (lean) gases. Moreover, we have analyzed the effect of different injection gases (IGs) and found that carbon dioxide (CO2) yields a higher water cut compared with methane (C1). Moreover, our findings have revealed the trapping mechanisms of hydrocarbon-water mixtures in shale rocks and have highlighted the impacts of pore structures on the recovery of shale reservoirs. As such, we have provided a potential explanation of the observed phenomenon.

Preliminary purification of the gas-liquid stream from hydrocarbon condensate, water and mechanical impurities

The paper discusses the process plan of the piston compressor package as well as the design of the gas separator. A technical proposal has been developed to improve the preliminary purification of the gas-liquid stream from hydrocarbon condensate, water and mechanical impurities. With the help of modern computer technologies, the design of the inlet device in the separator has been developed. The operation of the gas separator was simulated after the application developed by the devices. With the help of the program, the results of the study of the gas separator operation are presented.

METHODS FOR INCREASING THE CONDENSATE RECOVERY COEFFICIENT WHEN DEVELOPING GAS CONDENSATE FIELDS

This article will discuss methods for increasing the condensate recovery coefficient and the concept of condensate recovery. Gas condensate is a cold hydrocarbon reservoir that includes natural gas as well as liquid hydrocarbons, often in the form of liquid condensate. During reservoir extraction, liquids are mixed from mixtures of light hydrocarbons (eg methane, ethane, propane) and denser liquid hydrocarbons (known as condensates). Gas condensates are found in underground reservoirs, where temperature and pressure conditions allow the gas to condense into liquid form as it moves from the formation to the surface. Such situations are often observed in tanks where there is a combination of increased pressure, high temperatures and a specific gas composition. The condensate production indicator from the reservoir describes the level of gas condensate extraction from gas condensate and oil and gas condensate fields. A distinction is made between instantaneous condensate production (determined at a certain point in time) and final production (at the end of commercial exploitation of the field). To quantify condensate production, the condensate production indicator is used - this is the ratio between the given definition of condensate and the reserves taken from the reserves of the field based on its study (expressed as a percentage or fraction of units). This indicator is used to extract recoverable condensate reserves. In addition, it is taken into account when developing a project for a gas condensate or oil and gas condensate field, taking into account the efficiency of the technology used. The completeness of condensate removal in some cases determines the reasonableness of developing the selected system. The main features of the behavior of gas condensate systems are associated with the corresponding phenomena reflected in the phase diagrams of reverse condensation and evaporation. These features lead to the fact that when the pressure in the gas condensate system decreases to a level below the saturation pressure, condensation of heavier hydrocarbons (condensate) occurs. If the pressure in the gas condensate formation during development is maintained at the initial level (or the pressure at the beginning of condensation), then phase transitions occur only in the formation zones adjacent to the well. This requires taking into account changes over time, such as changes in filtration characteristics in the bottomhole zones of wells. When developing a gas condensate field to the point of depletion, condensate begins to fall out everywhere in the reservoir. However, the condensate that falls often has little effect on the gas saturation coefficient of the entire formation. Consequently, when developing a gas condensate field until depletion (with a low condensate content in the gas), filtration flows can be considered as single-phase, since the precipitated condensate remains motionless. Low condensate saturation of the formation leads to slight changes in its capacitive and filtration characteristics. In the zone of the bottomhole space of the formation, two-phase filtration occurs. Keywords: gas, gas condensate, heavier hydrocarbons, dew point, the condensate recovery coefficient.

Heavy hydrocarbon recovery with integration of turboexpander and JT valve from highly CO2-containing natural gas for gas transmission pipeline

Demand of natural gas is predicted to increase since many valuable products can be produced. Water and heavy hydrocarbon content are the key for gas pipeline facility. To meet requirement of natural gas transportation, dehydration unit (DHU) and hydrocarbon dew point control unit (DPCU) are necessary to avoid water and hydrocarbon condensation during transmission. The conventional dehydration technology, TEG contactor, can lower water content from 1,304 mg/m3 to 80.35 mg/m3 where the maximum limit of water content in natural gas is 97 mg/m3 to prevent hydrate formation. DPCU is installed to remove heavy hydrocarbon, especially C5+. Integration of JT valve and turboexpander was employed to obtain the low gas dew point. The hot gas stream that entered the JT valve was observed. The lower hot bypass gas was applied, the lower hydrocarbon dew point and the more condensate flowrate was achieved. The highest power generation can be gained at low hot gas flow ratio which also influenced the exit pressure and temperature of compressor. In pipeline simulation, the pressure and temperature drop occurred at the high hot gas rate. To examine the arrival condition, dew point curves were generated and showed that the limitation of hot gas flow ratio has to be below 0.6 to prevent heavy hydrocarbon condensation in pipeline.

Evaluation of the Fischer‐Tropsch synthesis product selectivity over iron‐based silica‐supported catalyst under mild temperatures

AbstractThe circular economy is considered a keystone of sustainable development, and its implementation requires analyzing both product and by‐products, as well as process waste. In this study Fischer‐Tropsch synthesis product selectivity over Fe/SiO2 catalyst was investigated in the reaction temperature range of 240 to 300°C. The composition of the gas, liquid hydrocarbon, and wax products is discussed alongside the aqueous phase, which is rarely addressed. It was found that 280°C is the optimal temperature for condensable hydrocarbon production over Fe/SiO2 catalyst. The increase in reaction temperature led to a decrease in the selectivity of 1‐olefins and alcohols in the liquid hydrocarbon phase and waxes, but at the same time contributed to an increase in the content of alcohols in the aqueous phase products.

Эффективность трубчатой печи в процессе стабилизации углеводородного конденсата на Астраханском газоперерабатывающем заводе

One of the most important and promising areas of Russia's development for the coming decades is the in-troduction of energy-efficient and energy-saving technologies. designated by the President of the Russian Federation. Currently, in Russia, various types of technological tubular furnaces with natural thrust are widely used at many gas processing plants and refineries. The bulk of tubular furnaces are operated by personnel without any automation systems and regulation of the supply of both fuel and air. The article discusses the issues of efficient operation of a tubular furnace during stabilization of hydrocarbon condensate with acidic components at the Astrakhan Gas Processing Plant. When designing a tubular furnace, various options for efficient operation with the utilization of the thermal energy of exhaust flue gases are considered. It is established that the maximum efficiency of a tubular furnace is obtained not only when the flue gas temperature at the outlet of the chimney is minimal, but depends on a number of factors that are discussed in more detail in this article.

Investigating the synergistic driving action of microwave and char-based multi-catalysts on biomass catalytic pyrolysis into value-added bio-products

A method for preparing value-added bio-products dominated by aromatic hydrocarbon bio-oil with high selectivity by fast pyrolysis of biomass under the synergistic effect of microwave and char-based multi-catalysts (CMCs) was proposed. Various CMCs were prepared, and their structural characteristics were compared in detail. Microwave pyrolysis (MWP) experiment shows that the synergistic of microwave and biochar (hot spot effect) activates the active sites of molecular sieve catalysts, which can improve the diffusion of heavy components, thus regulating the pyrolytic products. Two non-noble metal active sites were introduced into CMCs, and their pyrolysis characteristics were compared. The Zn-modified CMCs showed good selectivity to monocyclic aromatic hydrocarbons. The yield of monocyclic aromatic hydrocarbons (MAHs) increased to 28.49 %, and the content of C6 ∼ C8 aromatic hydrocarbons was obviously increased, especially in the decarbonylation reaction. The Zr-modified CMCs could inhibit the transition condensation and cyclization of aromatic hydrocarbons. The ratio of MAHs to polycyclic aromatic hydrocarbons (PAHs) reached 1.31–1.42, which optimized the distribution of liquid products, and the yield of MAHs was between 22.99–28.61 %. CMCs have the characteristics of microwave absorption and catalytic conversion of aromatic hydrocarbons with high activity.

Effects of oxygen addition to the fuel stream on the soot formation in an ethylene coflow partially premixed flame based on the orthogonal decoupling method

In this work, an orthogonal decoupling method based on the orthogonal design and decoupling method was used to simulate the effects of adding oxygen (O2) to the fuel stream on the soot formation characteristics in an ethylene (C2H4) coflow partially premixed flame. The dilution effect, thermal effect and chemical effect of the added O2, as well as the interaction between these effects were decoupled and analyzed. Results show that the peak soot volume fraction (SVF) in the flame decreases first and then increases as the O2 mole fraction gradually increases to 30%, and is lowest at an addition of 20%. The orthogonal decoupling calculations were performed for two O2 concentration ranges of 5%–10% and 25%–30%, and the differences on soot formation at these two ranges were found to be dominated by the chemical effects of O2 through the extremum difference analysis of the calculated peak SVF, number density of primary particle and particle aggregation degree. The chemical effect of O2 inhibits the formation of soot at an O2 addition of 5%–10%, while promotes the formation of soot at an O2 addition of 25%–30%, by affecting the inception, hydrogen-abstraction-carbon-addition (HACA) reaction, and polycyclic aromatic hydrocarbon (PAH) condensation rates of soot formation. When the O2 concentration is 25%–30%, the chemical effect of O2 promotes the soot surface growth rate and therefore increases the soot particle size, which in turn retards the complete oxidation process, leading to an increase in SVF.

Hydrothermal Carbonisation as Treatment for Effective Moisture Removal from Digestate—Mechanical Dewatering, Flashing-Off, and Condensates’ Processing

One of the processes that can serve to valorise low-quality biomass and organic waste is hydrothermal carbonization (HTC). It is a thermochemical process that transpires in the presence of water and uses heat to convert wet feedstocks into hydrochar (the solid product of hydrothermal carbonization). In the present experimental study, an improvement consisting of an increased hydrophobic character of HTC-treated biomass is demonstrated through the presentation of enhanced mechanical dewatering at different pressures due to HTC valorisation. As part of this work’s scope, flashing-off of low-quality steam is additionally explored, allowing for the recovery of the physical enthalpy of hot hydrochar slurry. The flashing-off vapours, apart from steam, contain condensable hydrocarbons. Accordingly, a membrane system that purifies such effluent and the subsequent recovery of chemical energy from the retentate are taken into account. Moreover, the biomethane potential is calculated for the condensates, presenting the possibility for the chemical energy recovery of the condensates.

H2/NH3 Addition Effects on Flame Characteristics and Soot Formation in Ethylene Inverse Diffusion Flame

Zero-carbon alternative fuels such as hydrogen and ammonia are gaining popularity. Blending these fuels with hydrocarbons is an intermediate approach to mitigate soot and carbon dioxide production. Recent studies have concentrated their attention to the effects of ammonia and hydrogen on the soot production of hydrocarbon fuels. It is still necessary to completely comprehend how this influence is dependent on the type of fuel and flame configuration. In this work, the effect of hydrogen and ammonia addition on soot production in ethylene laminar inverse diffusion flames (IDF) was numerically examined for the first time. The thermal, chemical, and combined effects of hydrogen and ammonia were assessed by fictitious species. The experimental results from the literature were used to validate the temperature and soot volume fraction profiles. Results indicated that the flame temperature and the production of radicals are promoted chemically by hydrogen addition but inhibited under the thermal effect of ammonia. The principal source of the reduction in OH-represented flame height, soot volume fraction, average diameter, and primary particle number density in the IDF is the thermal effect of additives, and hydrogen addition performs better than ammonia. The major and intermediate species, the aromatic hydrocarbons, and the soot formation or oxidation reaction rates are decreased mainly by the hydrogen and ammonia thermal effect while increased moderately by the chemical effect. Therein, the reduction in soot generation is mainly due to the polycyclic aromatic hydrocarbon condensation rate being slowed down by additives. The inhibition is attributed to the thermal effect of additions, and hydrogen behaves better than ammonia.

Steam reforming of tar using biomass gasification char in a Pilot-scale gasifier

Gasification char is a residual material produced during the biomass gasification process. Considered as industrial waste, it is typically disposed of through incineration or landfilling, thereby incurring significant economic costs. Nonetheless, gasification char is characterized by its high carbon content and surface area making it an economical alternative to common catalysts and catalyst support materials. In this study, char from a pilot-scale downdraft gasifier was used to reform the tar generated from the same gasifier. Reforming was performed both in the presence and absence of steam. The aim is to convert condensable hydrocarbon derivatives (tars) into non-condensable lower molecular weight products such as H2 and CO. Reforming test conducted with 0.18 kg/h steam for 2 h at 750 °C and char bed weighing 600 g resulted in a reduction of tar concentration from 2407 mg/Nm3 to 20 mg/Nm3. The same test conditions were also responsible for an increase in H2 production from 15 to 26 vol%. The combined effect of steam and char bed suggests that both upgrading the producer gas as well as cleaning it can be made possible in a single process.

Analysis of the local growth and density evolution of soot deposits generated under hydrocarbon condensation: 3D simulation and detailed experimental validation

The utilization of the Exhaust Gas Recirculation (EGR) system during atypical engine operating conditions in order to meet future type-approval criteria exposes the internal surfaces of the devices to exhaust gas with elevated concentrations of particulate matter and greater amounts of hydrocarbon species, leading to the formation of dense and wet sludge deposits. To broaden the understanding of this phenomenon and contribute to the development of advanced EGR devices, this study presents an extended Computational Fluid Dynamics (CFD) model that, in addition to simulating the growth of fouling deposits caused by the accumulation of soot particles, also takes into account the condensation of hydrocarbons. Two scenarios with varying hydrocarbon concentrations in the exhaust flow are analysed, and the evolution of the deposit's thickness and density is determined. A sequential validation process is carried out by comparing the numerical results to actual deposit profiles at different stages of the fouling process. Additionally, hyperspectral images of the fouling layer have been acquired and analysed to validate the regions where hydrocarbon condensation is predicted to play a crucial role, enabling the verification of the hydrocarbon condensation phenomenon predicted by the numerical model. The results obtained under the studied conditions indicate that, on average, 77.4% of the analysed area exhibits a low level of relative error, demonstrating that the proposed model and the methodology used serve as a valuable tool for examining the propensity for deposit formation in devices subjected to fouling exacerbated by hydrocarbon condensation.

Numerical simulation of condensation from isobutane vapour – air mixture

Hydrocarbon condensation has been a topic of interest in recent years due to its applications in refrigeration, chemical processing and air conditioning. The condensation of friendly fluids reduces the Global Warming Potential and Ozone Depletion Potential, which can be used as an alternative to many hydrofluorocarbon (HFC) refrigerants. The main objective of this study is to investigate the combined heat and mass transfer of laminar film condensation from isobutane vapour in the presence of a small percentage of non-condensable gas (air) inside a vertical tube. The external tube wall is subjected to a constant temperature. To achieve our goal, a mathematical model based on mass conservation, momentum, and energy in both gas and liquid phases is established. The discretization of equations in each region with the boundary conditions is realised using an implicit finite difference scheme. The validity of the numerical model developed is verified in comparison with the results of the literature. The obtained results show that the condensation process is enhanced by increasing the inlet velocity and the inlet-to-wall temperature difference. Moreover, the results indicate that the presence of non-condensable gas reduces the efficiency of heat and mass exchanges.

Кинетические особенности термолиза газойлей каталитического крекинга

The high-temperature macrokinetics of the process of thermolysis of low-sulphur catalytic cracking gas oil with the formation of needle coke was studied. The experiments were carried out on a laboratory setup with a quartz microreactor at temperatures of 450-500 °C and a process duration of up to 300 min. It was established that the process is two-stage and its kinetics obeysthe Avrami-Erofeev equation, the rate constant of the process at both stages has a diffusion character. The second stage includes thermal condensation of polycyclic hydrocarbons with the formation of mesophase and needle coke. The results of the study are confirmed by optical microscopy in polarized light, data of electron paramagnetic resonance and electron spectroscopy.

State Primary Standard of Relative Humidity of Gases, Molar (Volume) Fraction of Moisture, Dew/Frost Point Temperature, Hydrocarbon Condensation Temperature Units Get 151-2020

State Primary Standard of Relative Humidity of Gases, Molar (Volume) Fraction of Moisture, Dew/Frost Point Temperature, Hydrocarbon Condensation Temperature Units Get 151-2020