Solubility Of Hydrocarbons Research Articles

Bio-electrokinetic remediation of crude oil contaminated soil enhanced by bacterial biosurfactant

The present study evaluating the coupling between bioremediation (BIO) and electrokinetic (EK) remediation of crude oil hydrocarbon by using bio-electrokinetic (BIO-EK) technique. The application of bacterial biosurfactant (BS) may increase the remediation efficiency by increasing the solubility of organic materials. In this work, the potential biosurfactant producing marine bacteria were isolated and identified by 16S rDNA analysis namely Bacillus subtilis AS2, Bacillus licheniformis AS3 and Bacillus velezensis AS4. Biodegradation efficiency of crude oil was found as 88%, 92% and 97% for strain AS2, AS3 and AS4 respectively, with the optimum temperature of 37 °C and pH 7. FTIR confirm the BS belongs to lipopeptide in nature. GCMS reveals that three isolates degraded the lower to higher molecular weight of the crude oil (C8 to C28) effectively. Results showed that use of BS in electokinetic remediation enhance the biodegradation rate of crude oil contaminated soil about 92% than EK (60%) in 2 days operation. BS enhances the solubilization of hydrocarbon and it leads to the faster electromigration of hydrocarbon to the anodic compartment, which was confirmed by the presence of higher total organic content than the EK. This study proven that the BIO-EK combined with BS can be used to enhance in situ bioremediation of petroleum contaminated soils.

The Complexity of Spills: The Fate of the Deepwater Horizon Oil.

The Deepwater Horizon oil spill was the largest, longest-lasting, and deepest oil accident to date in US waters. As oil and natural gas jetted from release points at 1,500-m depth in the northern Gulf of Mexico, entrainment of the surrounding ocean water into a buoyant plume, rich in soluble hydrocarbons and dispersed microdroplets of oil, created a deep (1,000-m) intrusion layer. Larger droplets of liquid oil rose to the surface, forming a slick of mostly insoluble, hydrocarbon-type compounds. A variety of physical, chemical, and biological mechanisms helped to transform, remove, and redisperse the oil and gas that was released. Biodegradation removed up to 60% of the oil in the intrusion layer but was less efficient in the surface slick, due to nutrient limitation. Photochemical processes altered up to 50% (by mass) of the floating oil. The surface oil expression changed daily due to wind and currents, whereas the intrusion layer flowed southwestward. A portion of the weathered surface oil stranded along shorelines. Oil from both surface and intrusion layers were deposited onto the seafloor via sinking marine oil snow. The biodegradation rates of stranded or sedimented oil were low, with resuspension and redistribution transiently increasing biodegradation. The subsequent research efforts increased our understanding of the fate of spilled oil immensely, with novel insights focusing on the importance of photooxidation, the microbial communities driving biodegradation, and the formation of marine oil snow that transports oil to the seafloor.

Experimental Measurement and Thermodynamic Modeling of Methane Solubility in Triethylene Glycol within the Temperature Range of 343.16–444.95 K

Triethylene glycol (TEG) is widely used in the gas dehydration process. While absorbing water from the gas, some hydrocarbons may also be absorbed. Knowledge of hydrocarbon solubility in TEG is nec...

Estimation of Solubility of BTEX, Light Hydrocarbons and Sour Gases in Triethylene Glycol Using the SAFT Equation of State

An accurate prediction of the absorption and desorption of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) is important for the estimation of BTEX emissions from glycol units in natural gas processing plants. This work presents an approach to accurately model the solubilities of BTEX in triethylene glycol (TEG). The absorption of gases studied in this work into TEG is physical in nature, and therefore is treated as physisorption in modeling. The Huang-Radosz version of Statistical Associating Fluid Theory (SAFT-HR) Equation of State (EoS) was utilized to estimate the solubilities of BTEX in TEG. A new set of SAFT parameters for TEG, as well as a new set of binary interaction parameters between TEG and other components were obtained by fitting experimental vapor pressure and liquid density of TEG and available experimental binary VLE data, respectively. Using these parameters, solubility of multicomponent gases in TEG are accurately predicted. To have an estimate of the relative accuracy of SAFT-HR EoS, the results from Perturbed–Chain SAFT (PC–SAFT) and Peng–Robinson (PR) EoS are also reported. The overall average of root–mean–square deviation (RMSD) for binary and ternary systems studied in this work, using SAFT-HR, PC–SAFT, and PR EoS obtained equal to 0.12, 0.20, and 1.56, respectively.

Solubility of propane in N‐formyl morpholine

AbstractN‐formyl morpholine (NFM) is a solvent that has been used to separate acid gases from gas streams. An advantage of NFM is the high solubility of acid gases compared with the low solubility of light hydrocarbons. The solubility of the light hydrocarbons in NFM is important, as the hydrocarbons constitute a loss to the process, and result in hydrocarbon emissions to the atmosphere. However, there are only a few experimental data sets dealing with the solubility of hydrocarbons in NFM. To provide data to be used in the design of plants in the natural gas processing industry, the solubility of propane (C3H8) in NFM was measured at 298.15, 313.15, and 343.15 K at pressures up to 20.15 MPa. The Peng‐Robinson equation of state was employed to correlate the experimental data and to obtain binary interaction parameters. The binary interaction parameters were used to obtain the parameters of the Krichevsky‐Ilinskaya equation and Henry's law constants for propane were calculated. Henry's law constants for propane were compared with those of hydrogen sulphide, carbon dioxide, methane, and ethane in NFM.

A molecular dynamics simulation investigation on the solubility of polycyclic aromatic hydrocarbons in supercritical water

Polycyclic aromatic hydrocarbons (PAHs) are typical chemical pollutants from coal or organic matters. The solubility and conversion of PAHs in water phase are the prerequisite of complete gasification of organic matter or coal and the rate-determining step. This paper is supposed to provide a theoretical basis of restraining coking for ensuring efficient gasification. In this work, molecular dynamics (MD) simulation investigations focused on dissolution of macromolecules including PAHs were summarized and relevant problems were outlined. MD simulations on the solubility of PAH mixtures in supercritical water were carried out for the purpose of illuminating the behaviors of oil droplets containing PAHs under the extreme hydrothermal circumstances. Water densities were ranging from 0.1 g/cm3 to 0.3 g/cm3 in this study. The calculation results indicated that the solubility of light PAHs such as naphthalene was complete and thorough in supercritical water, while heavy PAHs such as benzo[ghi]perylene were sensitive to the thermodynamic state of water solvent. As for PAHs mixtures, light PAHs were inclined to be dissolved, while heavy PAHs were more likely to form PAH aggregates. Furthermore, effects of pressure on solubility were not significant. The increase in temperature and density was primarily beneficial to enhance the solubility of PAH mixtures in supercritical water.

Extreme Learning Machine-Based Model for Solubility Estimation of Hydrocarbon Gases in Electrolyte Solutions

Calculating hydrocarbon components solubility of natural gases is known as one of the important issues for operational works in petroleum and chemical engineering. In this work, a novel solubility estimation tool has been proposed for hydrocarbon gases—including methane, ethane, propane, and butane—in aqueous electrolyte solutions based on extreme learning machine (ELM) algorithm. Comparing the ELM outputs with a comprehensive real databank which has 1175 solubility points yielded R-squared values of 0.985 and 0.987 for training and testing phases respectively. Furthermore, the visual comparison of estimated and actual hydrocarbon solubility led to confirm the ability of proposed solubility model. Additionally, sensitivity analysis has been employed on the input variables of model to identify their impacts on hydrocarbon solubility. Such a comprehensive and reliable study can help engineers and scientists to successfully determine the important thermodynamic properties, which are key factors in optimizing and designing different industrial units such as refineries and petrochemical plants.

Pillared graphene oxide composite as an adsorbent of soluble hydrocarbons in water: pH and organic matter effects

Graphene oxide (GO) is a single-atom-thick sheet of carbon with oxygen-containing functional groups decorating its basal plane and edge sites. Most of its high surface area can be lost due to restacking of individual layers during the synthesis and drying of GO-based bulk sorbents. There is great interest to increase the specific surface area of graphene-based sorbents by introducing organic molecules as “pillaring agents” between GO sheets to hinder the stacking process and create sorbents with elevated surface area. This work synthesizes pillared GO by introducing chitosan (CS), a linear polysaccharide with various molecular weights. A composite of low molecular weight CS at a CS/GO ratio of 0.1 is shown to have the highest specific surface area (up to 70.5 m2/g) in comparison to the medium and high CS molecular weight, pristine GO, and the CS/GO composite materials. The affinity of the optimized GO/CS composites towards benzene, toluene, and naphthalene was evaluated at 19.3 mg/L of organic matter content while altering pH. Sips and Langmuir adsorption isotherm models well described the adsorption behavior, and benzene adsorption performance was reduced at low pH. Related to the presence of dissolved organic matter (DOM) in solution, lower diffusivity constants (k1) in hydrocarbon systems were recorded. Our results demonstrate the feasibility of CS as a potential pillaring agent in CS/GO composites to increase specific surface area and enhance the capture of soluble hydrocarbons from aqueous solutions.

Generalization of solubility of aromatic substances in supercritical fluid media with the use of entropy method of similarity theory

The results of generalization of the solubility of aromatic hydrocarbons in supercritical carbon dioxide using the entropy method of similarity theory are presented. The subject of generalization was the experimental data of various authors on the solubility of 11 substances studied in the temperature range from 300 to 350 K (total 823 experimental points and 57 isotherms).

Developing a new correlation for the aliphatic and aromatic hydrocarbon diffusion coefficients at infinite dilution in ionic liquids

In this work the Taylor dispersion technique has been used to measure the diffusion coefficients of n-heptane and toluene at infinite dilution in four ionic liquids, namely 1-ethyl-3-methylimidazolium thiocyanate ([emim][SCN]), 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][TCM]), 1-butyl-3-methylimidazolium tricyanomethanide ([bmim][TCM]), and 1-butyl-4-methylpyridinium tricyanomethanide ([4bmpy][TCM]), at the range temperatures from (298.2–333.2) K. The hydrocarbon diffusion is faster at higher temperatures because of the lower ionic liquid viscosity, and toluene diffuses faster than n-heptane due to its smaller molecular volume. In addition, it is seen that the values of the n-heptane diffusion coefficients decrease with an increase in the molecular weight and molar volume of the ionic liquid. The same is observed for the diffusion coefficients of toluene in the most viscous ionic liquids ([bmim][TCM], [4bmpy][TCM] and [4empy][Tf2N]), but, conversely, they increase for the least viscous ionic liquids ([emim][SCN], [emim][DCA], and [emim][TCM]). This behavior suggests that the strength of the toluene-ionic liquid chemical interactions have a significant effect on diffusion. A new empirical correlation has been proposed as a variation of the Wilke-Chang equation. Two additional variables have been introduced in this correlation; the molar fraction of the maximum hydrocarbon solubility, to take into account the toluene-ionic liquid interactions, as well as the molar volume of the ionic liquid, because of the huge difference between them and the solute. This new correlation satisfactorily fits the experimental data with an average deviation of 9.6%.

Geochemical characteristics of the organic matter in UPPMRs and the implication for fluid–rock exchange due to the retrograde metamorphism in the Dabie–Sulu orogenic belt, North China

The samples were collected from ultrahigh-pressure para-metamorphic rocks (UPPMRs) around 500–2000 m deep by Chinese Continental Scientific Drilling. The combined method of ultrasonic disintegrator and Soxhlet was strictly conducted to extract the indigenous hydrocarbons from the UPPMRs, to obtain non-contaminated and entire organic matter to reveal the geochemical characteristics and origin of hydrocarbons in the UPPMRs. Through gas chromatography–mass spectrometry analysis, the ratios of Pr/Ph in the soluble hydrocarbon were from 0.04 to 0.87. It was inferred that the precursor of extracts would be deposited in the anoxic setting. Based on the relative content among C27, C28 and C29 steranes, it was found that the main source of organic matter was marine algae. But the isomer ratios of C31 hopane 22S/(22S + 22R) were 0.39–0.69, and the distribution range of C29 sterane 20S/(20S + 20R) was 0.41–0.63, both of which reflected the equivalent maturity of organic matter was no more than 1% (Ro%). Therefore, the immature organic matter derived from algae obviously conflicted with its host rock, which experienced ultrahigh-pressure metamorphism. Therefore, this sort of immature organic matter probably is of secondary origin. Furthermore, the chromatography of n-alkane almost assumes bimodal distribution, and the data of Tmax ranges from 394 to 565°C, as S1/total organic carbon (TOC) ratios systematically increase with the corresponding Tmax. Therefore, it could be further proved that the organic matter in the UPPMRs probably is of mixed origin and is mainly derived from immigrant hydrocarbons during the stages of subduction and retrograde metamorphism. The emergence of Zr-in-rutile also indicates that the geological temperature was lower than that during the peak of metamorphism. Therefore, it could be inferred that the kerogen associated with rutile might go through diagenesis regularly at the stage of retrograde metamorphism. It was also shown that the δ18O value suddenly reduced up to −10‰ corresponding to the highest TOC (1820 μg/g) around the subduction fault. The relationship between the TOC and δ18O value indicated that the fluid–rock exchange reaction was the main reason for the immature organic matter present in the para-metamorphic rock. The returned subduction and retrograde metamorphism resulted in the activity of the formation fluid, which could prominently impact the geochemical characteristics of the para-metamorphic rock and should also be considered in the geodynamics research of the metamorphic orogenic belt.

Macromol. React. Eng. 4/2019

Front Cover: This article demonstrates a method to parameterize predictive models for hydrocarbon solubility in semicrystalline polyethylenes. The method reproduces solubility data at high loading, as well as in the dilute (Henry) regime. Such models are useful in predicting hydrocarbon absorption in polymer granules produced in the Gas Phase Polyethylene process, supporting kinetic modeling and purging processes. This is reported by Bruce J. Savatsky, Joseph A. Moebus, and Brian. R. Greenhalgh in article 1900003.

Computation of the Solubility of Aromatic Hydrocarbons in Supercritical Media Based on the Entropic Method of Similarity Theory

The results of generalizing the solubility of aromatic hydrocarbons in supercritical carbon dioxide using the entropy method of similarity theory are presented. Experimental data from different authors on the solubility of 11 substances studied in a temperature range from 300 to 350 K (728 experimental points and 50 isotherms) are subjected to generalization. It is shown that the dependency makes it possible to compute the solubility of aromatic hydrocarbons subjected to generalization in supercritical carbon dioxide to an acceptable accuracy.

The perfluoropolymer upper bound

AbstractPerfluoropolymers have fundamentally distinct thermodynamic partitioning properties compared to those of their hydrocarbon counterparts. However, current upper bound theory assumes hydrocarbon solubility behavior for all polymers. Herein, the fundamental presupposition of invariance in solubility behavior to upper bound performance is critically assessed for perfluoropolymers and hydrocarbon polymers. By modifying solubility relationships, theoretical perfluoropolymer upper bounds are established, showing a positive shift of the upper bound front as a result of beneficial solubility selectivities for certain gas pairs, including N2/CH4, He/H2, He/N2, He/CH4, and He/CO2. Within the framework of the solution–diffusion model, an analysis is presented to compare two independent approaches often pursued in efforts to surpass the polymer upper bound: (a) achieving solubility selectivity via perfluoropolymers and (b) improving diffusion selectivity via rigid hydrocarbon polymers. This analysis demonstrates the significant benefit that can be achieved by considering both the chemical composition and morphology of solid‐state macromolecules when designing membrane materials.

H2 Solubility in Hydrocarbons Calculated by the COSMO-RS Method

The solubility of H2 in alkylic and aromatic hydrocarbons was quantum-chemical theoretically calculated through the conductor-like screening model for real solvents (COSMO-RS). The results show tha...

Insights into Ionic Liquid/Aromatic Systems from NMR Spectroscopy: How Water Affects Solubility and Intermolecular Interactions.

Hydrocarbon solubility and chemical interactions in ten imidazolium- and pyridinium-based ionic liquids (ILs) with four different anions (thiocyanate [SCN]- , dicyanamide [DCA]- , tricyanomethanide [TCM]- , and bis(trifuoromethylsulfonyl)imide [NTf2 ]- ) have been studied by 1 H and 13 C NMR spectroscopy. The anion structure has the main influence on the anion-aromatic chemical interaction strength; it is directly correlated to the NMR chemical shift deviations but not to the hydrocarbon solubility. The [TCM]- anion shows the largest chemical shift deviations, but the [NTf2 ]- anion has the highest hydrocarbon solubility due to steric effects. Higher water contents decrease the hydrocarbon solubility in ILs. Ion-water solvation mainly occurs until 1 molwater /molIL with the saturation limit at 10 molwater /molIL . Toluene-ion interactions are stronger than water-ion interactions in [DCA]- and [TCM]- -based ILs, but they have a similar or even lower strength in [SCN]- -based ILs.

Microscopic Properties of Hydrogen Peroxide Activated Crumb Rubber and Its Influence on the Rheological Properties of Crumb Rubber Modified Asphalt.

Crumb rubber modified (CRM) asphalt binder has been affirmed to improve resistance to rutting, moisture susceptibility, low-temperature cracking, and asphalt durability. However, CRM has poor compatibility with asphalt since crumb rubber molecules are vulcanized. The objective of this study was to develop a new method to prepare activated crumb rubber using hydrogen peroxide (H2O2) solution and to explore the rheological properties of H2O2 activated CRM (ACRM) asphalt. Three different percentages of H2O2 solution were used to activate crumb rubber. The surface properties of oxidized rubber were analysed using scanning electron microscopy. Moreover, the pore structure in rubber powder was investigated. The rheological properties of bitumen samples obtained from treated and untreated rubber were characterized by conducting dynamic shear rheometer tests. The test results show that the average pore size of the crumb rubber after activation with H2O2 solution is significantly smaller than that of the inactivated crumb rubber, and the volume and surface area of the crumb rubber pores change with H2O2 solution activation in a certain pattern. With the increase in H2O2 solution content, the contact surface between the particles increases, the floccules and pores of the powder increase, and the interface degree between the crumb rubber powder and the asphalt is strengthened. Solubility of the rubber hydrocarbon and the release ability of the carbon black particles from the crumb rubber in the asphalt binder increase, but the mechanical properties of the crumb rubber, including the strength, elasticity, and wear resistance, decrease. As a result, a reduction is observed in the elasticity, viscosity, high-temperature rutting resistance, and elasticity of the ACRM asphalt.

Effects of the water-soluble fraction of a crude oil on estuarine meiofauna: A microcosm approach

Although soluble hydrocarbons persist for only hours to days in aquatic environments, they potentially pose a high toxicity to aquatic biota. Here we investigate effects of the water-soluble fraction (WSF) of crude oil on estuarine meiofauna, with special focus on nematodes. Copepods and amphipods were the most sensitive taxa, disappearing almost completely within 3 weeks after exposure. In nematodes, we observed mostly sublethal short-term effects of WSF, such as changes in feeding-type composition and age structure. In the longer term (months), total nematode density and species composition were significantly affected, whereas different diversity indices did not exhibit significant responses. Deposit-feeding and predatory nematodes were the most affected feeding types. Nevertheless, sensitivity was species-specific, with sometimes opposing responses between even congeneric species. Our results demonstrate the need to assess WSF effects on communities at the species level and over time periods well exceeding the residence time of the WSF in the environment.

Parameterization of Models for Vapor Solubility in Semicrystalline Polyethylene

AbstractThis paper extends the previous article by the authors on the solubility of hydrocarbon vapors in semicrystalline polyethylenes produced in the gas phase process. That work demonstrates a computational model for solubility based on an activity coefficient modification of the Sako–Wu–Prausnitz equation of state. In that work, by fitting a key parameter, one related to the constraint of tie chains on polymer fluid behavior, to a single isopentane solubility isotherm, accurate predictions of hydrocarbon solubility in polymer granules over a range of temperature, pressure, and composition are reported. In the present work, additional experimental solubility data are reported, an error in the authors' previous article is corrected, and a useful parameterization method that improves the predictive capabilities of the model is demonstrated. By using the model to predict much of the authors' own experimental data, as well as that published by others in the field, it is demonstrated how the proposed parameterization method allows for accurate predictions using a limited amount of experimental measurements.

On the prediction of solubility of alkane in carbon dioxide using the LSSVM algorithm

The increasing global energy demand and declination of oil reservoir in recent years cause the researchers attention focus on the enhancement of oil recovery approaches. One of the extensive applicable methods for enhancement of oil recovery, which has great efficiency and environmental benefits, is carbon dioxide injection. The CO2 injection has various effects on the reservoir fluid, which causes enhancement of recovery. One of these effects is extraction of lighter components of crude oil, which straightly depends on solubility of hydrocarbons in carbon dioxide. In order to better understand of this parameter, in this study, Least squares support vector machine (LSSVM) algorithm was developed as a novel predictive tool to estimate solubility of alkane in CO2 as function of carbon number of alkane, carbon dioxide density, pressure, and temperature. The predicting model outputs were compared with the extracted experimental solubility from literature statistically and graphically. The comparison showed the great ability and high accuracy of developed model in prediction of solubility.