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Acrylamide, a probable human carcinogen present in heat-processed foods and environmental contaminants, requires sample extraction and preconcentration before chromatographic analysis. The method developed in this study employed derivatization with xanthydrol and dispersive liquid–liquid microextraction utilizing low-density anisole. Durian or potato chips were combined with deionized water, defatted with hexane, and subjected to precipitation of soluble carbohydrates and proteins using clarification reagents. Water samples were filtered through a membrane filter. Acrylamide was derivatized by introducing an acidic methanolic solution of xanthydrol at 50 °C. The derivatized acrylamide was extracted with 70 µL of anisole and vortexed, with the methanol from the xanthydrol solution serving as the disperser solvent. The anisole layer was analyzed using gas chromatography with both flame ionization and mass spectrometric detection. Linear calibration plots exhibited coefficients of determination >0.9997. The precision was measured at <10% RSD, and recoveries ranged from 84% to 107%. The quantitation limit varied from 2 to 10 µg kg−1 for processed chips and from 0.05 to 0.10 µg L−1 for water samples. Acrylamide was detected in all processed chip samples, with some concentrations exceeding the benchmark value of 750 μg kg−1. However, no acrylamide was identified in any of the water samples. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions is one of the largest energy and environmental challenges currently faced globally. To achieve carbon neutrality, the development of new technologies and simultaneous improvement of conventional technologies are required. Catalysis, which determines the success or failure and efficiency of the process, is at the center of addressing these problems. Innovative advancements in catalysis have been accomplished through the extensive research on catalytic materials. Oxygen storage materials with oxygen storage capacity (OSC) have been widely applied in supports and active cocatalysts for energy and environmental catalytic applications. This review provides knowledge on the extended applications (reforming, water-gas shift reaction, and partial oxidation of methane (POM) for high-value-added chemicals, including hydrogen production, deoxygenation of fatty acids for second-generation biofuel production, selective catalytic reduction of NOx with NH3, hydrocarbon (HCs) oxidation for emission control, CO oxidation for vehicle exhaust control and purification of gaseous product fuel, and soot oxidation for the removal of motor-type pollutants) of these materials, which are mainly used as three-way catalysts (TWC) in automotive catalysis, to the carbon-neutral field. In particular, this study focuses on the physico-chemical properties that are closely synergistic with OSC, such as reducibility, dispersion, surface acid/base properties, and physical properties, such as surface structure or morphology. [ABSTRACT FROM AUTHOR]

Modification reaction of lignite in subcritical H2O–CO system can significantly increase its caking index to more than 90. Separating and extracting the caking components from modified lignite, exploring the formation path of caking components, and establishing a kinetic model for the generation of these components are of significant importance for lignite hydrogenation reaction control. The lignite modified reaction was carried out in subcritical D2O–CO systems using the isotope tracer method. The formation path of caking components was defined by solvent extraction–IRMS–GPC combination technology. The results show that the soluble substances of tetrahydrofuran (TS) and benzene (BS) are the main caking components causing the structural transformation of lignite (A). The separation of n-hexane soluble (NS) also has an effect on the caking index of the modified coal. In the hydrogenation caking component formation stage, the lignite pyrolysis fragments combine with active hydrogen generated by water gas shift reaction to form caking substances, that is, A → TS + BS + NS. The formation activation energy of caking components is in the range of 0.39–58.24 kJ/mol. In the polycondensation caking component conversion stage, three soluble substances are converted in the order of TS → BS → NS, and the activation energy for the formation of caking components is 31.710–57.616 kJ/mol. [ABSTRACT FROM AUTHOR]

This novel research presents an investigation on petroleum products dehydration using the adsorption method by low-cost adsorbents. To investigate the performance of proposed process intended to separate emulsified water, synthetic stabilized water emulsions in different petroleum products (Gasoline, Kerosene, and Gas oil) which equal 300, 600, and 800 ppm were prepared. Afterwards, under batch conditions, natural zeolite and activated carbon as economic adsorbents were utilized for the dehydration process. The characteristics of adsorbent was examined using SEM and XRD analysis. The obtained results from BET analysis also depicted that the specific surface area of activated carbon was considerably more than that of zeolite. Results showed that both zeolites and activated carbon can effectively purify petroleum products from undesirable emulsified water. The comparison of the adsorbents' efficiency indicated that activated carbon has a higher affinity than zeolite for water in gasoline and gas oil, however, they had almost the same adsorption capacity in kerosene dehydration. The maximum water removal percentage of gas oil, kerosene and gasoline using zeolite was 84.84, 92.17, and 88.64, respectively. Dehydration by activated carbon also led to 86.44, 93.43 and 90.2 per cent water removal from gas oil, kerosene and gasoline, respectively. [ABSTRACT FROM AUTHOR]

The article presents the results of theoretical studies of the ignition process of a water-coal fuel particle under conditions of high-temperature heating at high pressures of the external environment. The authors have developed a new mathematical model of the water-coal fuel particles ignition under stress (pressure – Pg = 1–200 bar, and temperature Tg = 873–1273 K) heating conditions. The mathematical model differs from the known ones by a detailed description of the physicochemical processes occurring during the induction period of time, as well as the processes of phase transitions under high pressure conditions. Based on the results of numerical simulation of the ignition process, it was found that the pressure of the external environment (Pg) has a significant effect on the characteristics and conditions of ignition of water-coal fuel particles. It was shown that the tign(Pg) dependence is essentially nonmonotonic. The authors have established that when Pg changes in the range from 1 to 30 bar (for oxidizer temperatures (Tg = 873–1273 K), an increase in the ambient pressure leads to a nonmonotonic increase in tign. In this way such a dependence tign(Pg) is due to the joint influence of two significant parameters of the factor space, which significantly affects the dynamics of the thermal treatment of fuel. With an increase in the pressure of the mixture of oxidizer and combustible gases, the saturation temperature (the temperature of intense evaporation of water) increases, at the same time, the heat of the phase transition (QL) decreases and the rate of release of pyrolysis gases into the oxidizing environment decreases. Based on the results of the theoretical studies, it has been shown that for efficient combustion of water-coal fuel under the conditions of the combustion chambers of a GT at oxidizer temperatures Tg≥1073K, the pressure in the combustion chamber of the GT must be at least 50 bar. [ABSTRACT FROM AUTHOR]

The evaluation of gas content plays a key role in determining the efficient development of shale reservoirs. To better understand the gas–water miscible competitive adsorption mechanism in the pore-fracture system of water-bearing shale, the water vapor adsorption experiment of dry shale and the methane gas adsorption experiment of water-bearing shale were carried out to compare and analyze the competitive adsorption laws of formation water and methane gas on the shale surface under different temperatures, pressures, and water saturation conditions. Moreover, based on the molecular layer adsorption theory, the gas–liquid–solid interface competitive adsorption model considering the coupling of temperature, pressure, and water saturation was established to predict the actual gas content of water-bearing shale reservoirs. The results show that the main controlling factors affecting the adsorbed gas content of water-bearing shale are specific surface area, temperature, and water content in turn according to weight coefficients; Compared with the gas–solid adsorption model, the gas–liquid–solid competitive adsorption model has higher accuracy in calculation results, which are much closer to the desorption data of shale cores in Jiaoshiba area, Fuling, China. Hence, the competitive adsorption model provides a theoretical foundation for reasonably evaluating the exploitation potential of shale gas reservoirs. [ABSTRACT FROM AUTHOR]

The effect of phosphorus on the catalytic performance of molybdenum carbide for the reverse water-gas shift (RWGS) reaction was studied for the first time. It was found that the catalytic activity and selectivity of the P-doped molybdenum carbide catalysts were greatly related to their P/Mo molar ratios within a narrow range (0–0.1). It was obvious that increasing P/Mo molar ratio led to a decreased activity, but can effectively enhance selectivity. The P-doped molybdenum carbide with a P/Mo molar ratio of 0.05 was proposed to be more excellent than other P-doped molybdenum carbides in terms of both activity and selectivity, which was attributed to its higher oxophilicity and weaker affinity toward CO. [ABSTRACT FROM AUTHOR]

We report on a novel modus operandi in the gas-chromatographic determination of ultra small contents (from 20 ng/l) of acetylene dissolved in water by employing a flame-ionisation detector with hydrogen as a carrier gas. The method bases on the gas extraction of acetylene with a frontal variant of liquid-gas chromatography in a tube with fluro-plastic carrier and simultaneous catalytic hydrogenation of acetylene to produce ethane in the presence of platinum deposited on the sorbent surface. The method in view gives way to a 20-fold decrease in the detection limit of acetylene against extraction with no hydrogenation. A plausible application of the method is the assessment of anthropogenic impact on the environmental hydrosphere embarking from the concentration of dissolved acetylene. [ABSTRACT FROM AUTHOR]

Conventional control strategies usually employed in tankless gas water heaters present difficulty in controlling the hot water temperature when subjected to sudden changes in water flow rate. Inadequate control leads to temperature overshoots and undershoots with long settling times that severely affect the user comfort, increasing water and energy wastage and associated gas emissions. A strategy based on model predictive control is presented to reduce the impact of changes in hot water demand. A semi-empirical model, parameterized with experimental data and compatible with real-time simulation, is used for the heat cell. A tailored state observer is proposed, considering time-varying delays characterizing this thermal process. An automatic code generation software tool was developed for the embedded implementation of gas water heater predictive controllers. Numerical simulations and hardware-in-the-loop experiments were established to evaluate conventional and predictive control strategies. It was demonstrated that embedded model predictive control could be successfully implemented on computationally limited microcontrollers, even for thermal systems with extensive varying time delays. Predictive control has shown significant performance improvements, with decreased temperature fluctuations, a gain in comfort index from 36% to 75% and a reduction of up to 32 s in the settling time. [ABSTRACT FROM AUTHOR]

A procedure is reported for the efficient extraction and determination of phenolics from aqueous media. The approach is based on the dispersive micro-solid phase extraction using synthesized Co3O4 nanocube-functionalized nitrogen-doped melamine foam. The adsorption and desorption conditions were optimized by response surface methodology and one-variable-at-a-time approaches. The proposed method was fully validated. Under the optimized conditions, the limits of detection were lower than 0.5 ng mL−1. Calibration curves were linear in the range from 1.0 to 250.0 ng mL−1, 0.7 to 200.0 ng mL−1, 0.2 to 250.0 ng mL−1, and 1.0 to 250.0 ng mL−1 for phenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol, respectively. Enrichment factors and absolute recoveries from 17.5 to 20.7 and 70% to 83% were achieved. The method was successfully applied for trace monitoring of the analytes in environmental and industrial water samples with gas chromatography—flame ionization detection analysis. Satisfactory relative recoveries between 89.0% and 105.8% were obtained along with acceptable precision below 8.1%. This method is a simple, rapid, sensitive, and reliable protocol for efficient screening of the phenolics. [ABSTRACT FROM AUTHOR]

In this work, a host-guest system was designed to explore the adsorption and sensitivity of the Al - and Ga-doped BNNT to the Cytarabine (CYT) and gemcitabine (GEM) drugs at Grimme-corrected M06-2X/6-31+G(d) level of theory in the gas phase and water solvent. Both CYT and GEM drugs are chemisorbed on doped BNNTs with dispersion-corrected adsorption energies of - 35.0 (-14.0) to - 66.0 (-50) kcal/mol for CYT and - 27.0 (-17.0) to - 68.0 (-40.0) kcal/mol for GEM in the gas (water) media. Our population analysis reveals that charge transfer occurs from drugs to doped-BNNTs. An increase in CT values on going from CYT2(GEM2) based complexes to CYT1(GEM1) based ones is in good agreement with the increase in adsorption energies. Despite the long recovery time for drug desorption, some CYT2(GEM2) based complexes show small recovery times, indicating the potential use of doped BNNTs as nano-carriers. Furthermore, the decrease in H-L gap by 25% to 43% in Al- BNNT-based complexes and 32% to 49% in Ga-BNNT ones suggests that Al(Ga)-BNNTs can be utilized for sensing CYT and GEM drugs. [ABSTRACT FROM AUTHOR]

The mercaptopurine (MP) molecule's interaction with the pristine covalent triazine-based framework (CTF) was evaluated in the gas and the water medium. The S1 structure is the most stable form of MP/CTF complexes, with the Eads of −0.532 and −0.385 eV in the gas and water medium, respectively. The adsorption behaviour of the MP/CTF nanostructures is further discussed using band structure and partial density of state analyses. The MP drug adsorption reduced the band gap energy of the desired monolayer in the range of 47 to 71% for the studied complexes. The adsorbed drug on the surface of the CTF substrate can be released in the adjacency of tumour cells, and the therapeutic operation is carried out on the target cells. The recovery time indicates the suitability of the desired CTF as a carrier of the MP drug in drug delivery applications. [ABSTRACT FROM AUTHOR]

This study presents a multiscale model to simulate oxygen diffusivity in partially saturated concrete accounting for multiscale nature of concrete and water-gas distribution in its pore structure. At microscale, 3 D microstructure of cement paste ITZ is simulated, based on which the water-gas equilibrium distribution in capillary pore structure and oxygen diffusivity at different degrees of water saturation (DWSs) are mimicked using lattice Boltzmann models. Afterwards, a (n + 1)-phase model based on effective media theory is used to predict oxygen diffusivity in non-saturated concrete at mesoscale. Results indicate that the evolution of oxygen diffusivity with the increasing DWS follows an initial drop, a plateau, a slight decrease and a sharp decrease, which correspond to the decreasing gas-filled gel pores, depercolation of gas-filled gel pores, and decreasing gas-filled capillary pores until their depercolation. The role of ITZ in oxygen diffusion in non-saturated concrete becomes more remarkable with the increasing DWS. [ABSTRACT FROM AUTHOR]

The natural gas treatment plant is one source of CO2 emissions into the atmosphere. To tackle this issue, it is probable to inject CO2 into the wells and it can be used for enhanced oil recovery (EOR) application. However, the main setback is the high content of water in acid gas that could be converted to hydrate at high pressure in the pipelines. In this article, two different processes (solvent extraction, stripping gas) with two different solvents mono ethylene glycol (MEG), Tri ethylene glycol (TEG), are simulated in Aspen HYSYS. The stripping gas method is more efficient in terms of energy consumption, consuming 31.8% and 56.8% less energy than solvent extraction method for MEG and TEG solvents, respectively. Hydrate formation analyses showed that applying MEG as a solvent in the stripping gas method leads to a safer operation region. Economic evaluation depicts that the stripping gas method saves the total annual cost by 22.2% compared to solvent extraction. [ABSTRACT FROM AUTHOR]

Anecdotal evidence suggested heat stress in grapevines can be reduced if vines are fully irrigated during a heat stress but only a few cultivars have been evaluated. Accordingly, Vitis vinifera L. cv. Semillon vines were grown in controlled environments and treated to a four-day 40°C heat event with and without water stress. Berry size, sugar content, gas exchange and water potentials were measured. Results indicated water stress was relatively mild, but berry growth was reversed when exposed to the heat event and water stress added to this effect whereas control berries continued growing. Similar results occurred with the sugar accumulation process, except sugar immediately stopped accumulating but heat plus water stress reduced the amount of berry sugar further. The stress treatments also impaired photosynthesis and more so when combined with water stress. While reductions in photosynthesis were mostly a result of stomatal closure, but perhaps also non-stomatal limitations, the reduced photoassimilates, especially of the heat plus water stressed vines, contributed to the lowered sugar amounts in the berries. These data strongly supported the conclusion that water stress exacerbated the effects of heat stress. The corollary is heat stress effects on vines will be ameliorated if no water stress is present. [ABSTRACT FROM AUTHOR]

The barrier discharge ionization detector (BID) is one of the latest detection technologies used in gas chromatography (GC). 306 papers from 2012 to 2021 with GC-BID analyses were considered. An overview of the main applications with the BID, considering the trends for the most common analyses, explored compounds, extraction methods, and comparative studies with other detectors is shown. Interest in BID applications has grown, and the number of publications reflects this. Despite having the potential to analyze different compounds, gases are more explored, mainly H2, CH4, and CO. The BID should be further explored for water analysis, as studies show its good performance in larger quantities and at the level of traces. Most of the determinations of these compounds were applied in studies focused on CO2 reduction (by photocatalysis or electro-reduction) and biogas (for CH4). BID is effective for determinations on the order of mmol to µmol. Headspace extraction (HS) is most often applied BID analysis. Reduced dynamic range and nonlinear response to carbon mass are some disadvantages to BID. On the other hand, the BID has a signal-to-noise ratio (S/N) 100 times higher than thermal conductivity detector (TCD) (for inorganic gases and water), a high linear sensitivity for dodecane (LOD less than 1.0 pgC/sec) and other compounds (being able to reach µg/L). Combined with simple extraction methods such as HS, the BID allows quick and simple analysis with great sensitivity, in addition, it is a good alternative for the analysis of inorganic gases and water compared to usual detectors. [ABSTRACT FROM AUTHOR]

To quantitatively characterize the preservation conditions of shale gas in different wells, the formation water and gas composition characteristics of five wells (YC1, YY6, YY1, YK1, and QQ1) in southeastern Chongqing were analyzed. The formation water type of QQ1 and YK1 is CaCl2, and CY1 includes CaCl2 and NaHCO3 types. The CNa/Cl and Cd are low, while CCa/Mg and CCl/Mg are high, indicating that the retention degree of formation water is high. The formation water of YY6 and YY1 is NaHCO3 type, the CNa/Cl and Cd are high, while the CCa/Mg and CCl/Mg are low, indicating the strong connectivity of formation water. The N2 content of wells QQ1 and YK1 is below 32%, and 15N is between −7.33‰ and −1.98‰, the source of nitrogen is ammoniated in the process of organic matter pyrolysis and hydrocarbon generation, and the preservation conditions are relatively good. Therefore, the preservation conditions combined with the metamorphic degree of formation water and gas composition can be judged. [ABSTRACT FROM AUTHOR]

Water control is an effective method to enhance the oil recovery in the high water-cut reservoir. It is proved that the water production can be reduced by the entrapped gas in the oil field. But the mechanism is not well studied. In this paper, the mechanism of enhanced oil recovery by entrapped gas is studied by experiments and numerical simulation. Based on the core flooding tests and simulation study, the increments of oil recovery caused by entrapped gas are 8% and 2%, respectively. After the gas is entrapped in the core sample, the water relative permeability is decreased by 10.5% and the oil relative permeability is only decreased by 3.5%, which proved that the entrapped gas has a dramatic effect on blocking water phase. The more gas is entrapped, the more oil is produced. Different methods to achieve entrapped gas are also discussed, simultaneous water, and gas injection is a preferred entrapped gas formation method than gas injection method and water alternating gas injection method. Under the immiscible condition, the entrapped methane has a better performance on enhancing oil recovery than the entrapped nitrogen. [ABSTRACT FROM AUTHOR]

Nanoporous graphene, a unique graphene nanostructure, has been frequently used to form nanocomposites. A very important application of polymer/nanoporous graphene nanocomposite has been observed in membrane sector. This state-of-the-art review highpoints design, features, and advanced functions of polymer/nanoporous graphene nanocomposite membranes. The nanoporous graphene derived nanocomposites brought about numerous revolutions in high-performance gas purification membranes as well as water permeation membranes. The structural diversity of polymer/nanoporous graphene nanocomposites has facilitated membrane separation processes especially in separation of anticipated gaseous molecules, ions, and water contaminants. Future research on innovative nanoporous graphene-based membrane may overcome design/performance related challenging factors for technical usages. [ABSTRACT FROM AUTHOR]

Horizontal drilling and multi-stage hydraulic fracturing are the two key technologies for the successful development of shale gas reservoirs. However, there exist large uncertainties in optimizing hydraulic fracturing which affects water retention into shale matrix and gas productivity. In this work, a basic reservoir model with six-stage hydraulic-fracturing treatment was constructed to understand water retention and gas production in shale gas reservoirs. Gas diffusion, gas desorption, Darcy flow as well as non-Darcy flow were considered in this model. Then, a sensitivity study was performed to investigate the effects of hydraulic fractures on water retention and gas conductivity. The results indicate that only 34% of the fracturing water could be recovered back to the surface, and most of them remain in shale formations to interfere with gas production. The increase of fracture half-length, fracture width, fracture permeability, and fracture conductivity will reduce water retention while water retention in shale matrix will increase with the increasing of fracture spacing and fracture number. This work can provide a better understanding of the effects of hydraulic fractures on gas and water flow so as to optimize the hydraulic-fracturing treatment in shale gas reservoirs. [ABSTRACT FROM AUTHOR]

During lean gas reinjection after depletion in high-pressure and low-permeability reservoirs, the fluid composition in the formation changes greatly, the microscopic interaction process among fluids is complex, and the microscopic mechanism of lean gas flooding is not clear to us. In this article, the microscopic experiments were carried out in high-temperature and high-pressure micro-visualization experiment apparatus of independent research and development. The microscopic interaction process between lean gas and formation fluid before and after depletion was studied on the porous models made of glass by etching. The flow law of lean gas after depletion and the mechanism of microscopic oil displacement were discussed. The results from experiments conclude that lean gas flooding should alleviate the Jamin effect caused by gas separated from oil during depleted production. Under the reservoir conditions, the oil is produced by lean gas displacement force primarily, by lean gas extraction for auxiliary. The water barrier prevents the contact between lean gas and residual oil. In unswept areas of lean gas, the residual oil is difficult to be produced as the poor diffusion of lean gas through water barrier into residual oil. While in swept area, lean gas can peel off water film gradually, then contact with residual oil directly, and then drive out oil by dissolving and extracting. Lean gas flooding in high-pressure and low-permeability reservoirs can enhance oil recovery further after depleted production. [ABSTRACT FROM AUTHOR]

Based on the long-term exposure test of fly ash concrete under natural tidal environment, the gas permeability coefficient, water permeability coefficient, chloride concentration and microstructure parameters of fly ash concrete were tracked and tested. Relationships between permeability and exposure time as well as fly ash content were analysed. Time dependent models for permeability of concrete were established, and time dependent relationships among water/gas permeability, and chloride diffusivity were discussed. Based on the results of mercury intrusion porosimetry (MIP), the influence of fly ash content on time dependent porosity and pore size distribution (PSD) of concrete were analysed. Results show that fly ash can significantly reduce the porosity, instantaneous chloride diffusion coefficients, water and intrinsic gas permeability coefficients after the same exposure time. A time dependent chloride diffusivity model is established based on the time dependent intrinsic gas permeability coefficients. With the increasing exposure time and fly ash content, the proportions and contributive porosity (100 nm < d < 1000 nm) decrease gradually. Water and intrinsic gas permeability as well as chloride diffusivity of concrete are more closely related to the contributive porosity of large capillary pores (100-1000 nm). [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are commonly used in commercial products as flame retardants. In the present study, a simple method was established for the simultaneous determination of 10 OPEs in aquacultural water and sediments. The targets were extracted using dichloromethane or ethyl acetate, cleaned up by solid-phase extraction, and determined by gas chromatography – tandem mass spectrometry. The matrix effects were lower than 20% for all OPEs except for tris(2-chloroethyl) phosphate in sediments (matrix effect: 29.4%). In spiked water samples, the recoveries of the OPEs were from 72.3% to 108% with relative standard deviations ≤10.2% and the limits of detection from 0.17 to 1.13 ng·L−1. In spiked sediments, the recoveries of the OPEs were from 101% to 121% with relative standard deviations ≤11.2% with limits of detection from 0.02 to 0.32 ng·g−1, dry weight (dw). The developed method was applied to the analysis of aquaculture samples from Kaozhouyang Bay, China. The total concentration ranges of the 10 OPEs in the water and sediments were from 121 to 159 ng·L−1 and 7.54 to 13.3 ng·g−1, dw, respectively. [ABSTRACT FROM AUTHOR]

Mole fraction solubilities have been measured for anthracene, benzoic acid, 4-tert-butylbenzoic acid, 3-chlorobenzoic acid, 2-hydroxybenzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid, 3-nitrobenzoic acid and pyrene dissolved in cyclopentanone at 298.15 K using either spectrophotometric or acid-base titrimetric methods. Results of our experimental measurements, combined with published solubility data for several inorganic and organic gases, solubility data for several important crystalline pharmaceutical intermediates and activity coefficient data taken from the published literature, were used to derive Abraham model correlations for solute transfer into anhydrous cyclopentanone solvent from both water and from the gas phase. The derived Abraham model correlations back-calculate the observed experimental data to within 0.10 log units (or less). Reported for the first time are solute descriptor values for several important pharmaceutical intermediates. [ABSTRACT FROM AUTHOR]

In this study, an oxygen self-doped carbon aerogel (ODCA), synthesized via ambient pressure drying and carbonization, was employed as solid-phase microextraction (SPME) coating material for phthalate esters (PAEs) detection in water samples by gas chromatography (GC) coupled with a flame ionization detector (FID). The materials were obtained by incomplete carbonization of the phenolic aerogel at a controlled temperature of 950°C, which leads to a certain amount of oxygen self-doping in the carbon aerogel. The ODCA-coated fiber exhibited fascinating extraction properties for PAEs mainly due to its oxygen active sites, π-π interaction, high surface area, and porosity of carbon aerogel. This as-proposed fiber showed wide linearity ranges (0.5–500, 1.0–500, 1.0–1000, 2.0–500 μg L−1, respectively), and provided low limits of detection (LOD, 0.17–0.83 μg L−1) for PAEs analysis under the optimal conditions. The single fiber and fiber-to-fiber relative standard deviations at 100 μg L−1 were observed in the range of 5.31%–10.37% and 9.17%–16.65%, respectively. Moreover, this method was also used for the determination of five PAEs in real water samples. [ABSTRACT FROM AUTHOR]

A self-developed superheated water vapor pyrolysis system was used to conduct superheated water vapor pyrolysis experiments on Tashan and Madaotou long-flame coals at 350–534 °C. The gas phase products were analyzed by gas chromatography. The yield and composition of gas phase pyrolysis products from two different long-flame coals were determined, and the role of superheated water vapor in the pyrolysis process was elucidated. The optimal temperature of the long-flame coal injection superheated water vapor mining technology was obtained through heat value analysis. The results showed that when the temperature of the superheated water vapor exceeded 400 °C, the yield and combustible components of the gas phase products rapidly increased. As such, the release rate reached 10–15 times that observed below 400 °C, and the components of the combustible gases, such as hydrocarbon gas and hydrogen, exceeded 80%. Superheated water vapor not only is an excellent heat and mass transfer medium, but also provides a reactant for the re-formation reaction of hydrocarbon gas. The pyrolysis of long-flame coal under superheated water vapor at 500 °C yielded the best economic benefits. The low calorific value of gas phase products produced via pyrolysis per ton of coal per unit time could reach 715 MJ/(t·h). [ABSTRACT FROM AUTHOR]

Iron is a favored catalyst for Fischer-Tropsch (FT) synthesis, the production of hydrocarbons from synthesis gas. Zeolites are common catalysts for hydrocarbon processing. Here we review iron-based catalysts for FT, both alone and in combination with zeolites. The importance of the related water-gas-shift reaction (WGS) in specifying a FT catalyst is studied. For the iron-based catalyst, the effects of different catalyst supports are explained. The performance of such a catalyst when various metal promoters (Cu, K, Mo, and others) are added to it are compared. Several metal promoters on a Fe-based catalyst increase FT and WGS water-gas shift reaction activity, and also improve the stability of the catalyst. For the zeolite catalyst, changes in the final product profile with change in zeolite type are described. Zeolites are used to convert long-chain hydrocarbons produced by the FT process into gasoline- and diesel-range hydrocarbons. Zeolite use in optimization of olefin, aromatic, and branched products and conversion of oxygenates to hydrocarbons is explained based on several studies. Deactivation and the overall reaction sequence on zeolite catalysts are described. [ABSTRACT FROM AUTHOR]

The objectives of this article it to present a water alternating gas (WAG) process evaluation methodology for a giant middle eastern carbonate reservoir. The methodology involves enhanced oil recovery through an immiscible hydrocarbon water alternating gas (WAG) injection method. Although water alternating gas injection is a proven enhance oil recovery technique and has been around for some time now, only a limited published literature is available on complete evaluation of immiscible WAG process in field application. This article aims to bridge the gap by presenting a detailed study of immiscible water alternating gas evaluation process. In this article a complete methodology for evaluating a water alternating gas injection recovery technique is presented. It includes optimization of WAG cycle length, WAG ratio, production constraints, injected gas compositions, WAG duration, and WAG slug size. The work presented in this article could aid oil field operators to understand the impact of different parameters on immiscible WAG injection process and potentially help them to optimize production from their fields. [ABSTRACT FROM AUTHOR]

Water-alternating-gas (WAG) is one of the enhanced oil recovery (EOR) methods in which both water and gas are injected into the reservoir. Among different WAG processes, CO2-WAG is one the most environmental-friendly and efficient methods. The low minimum miscibility pressure (MMP) of CO2 turns this gas to a special candidate for EOR applications. In this study, impact of anisotropy coefficient and operating parameters including injection rate, pattern size and slug size on performance of this process was investigated through 360 different cases of numerical simulation. Also, a modification to the currently used dimensionless aspect ratio was proposed to enhance the accuracy of predicting oil recovery factor during WAG process. Generally, it was concluded that regardless of anisotropy coefficient, oil recovery factor increases as the ratio of well distance to reservoir thickness increases. For instance, for anisotropy coefficient of 0.1, the average recovery factor for well distance to reservoir thickness of 10 and 100 was 68% and 74%, respectively. In addition, it was concluded that the performance of WAG process is logarithmically correlated with anisotropy coefficient and well distance to reservoir thickness. Finally, it was concluded that the proposed modification for the dimensionless aspect ratio considerably increases its accuracy. [ABSTRACT FROM AUTHOR]

Mole fraction solubilities are reported for anthracene, pyrene, salicylamide, benzoin, benzil, thioxanthen-9-one, 1-chloroanthraquinone, and 4-methyl-3-nitrobenzoic acid dissolved in neat anisole at 298.15 K based on spectrophotometric measurements. Results of the experimental measurements, combined with published infinite dilution activity coefficient and solubility data gathered from the published chemical literature, are used to derive Abraham model expressions for describing solute transfer into anisole from both water and the gas phase. The derived mathematical equations describe the observed solute transfer coefficients to within the overall standard deviations of 0.14 log units (or less). [ABSTRACT FROM AUTHOR]

Experimental mole fraction solubilities are reported for acenaphthene, benzoin, salicylamide, o-acetoacetanisidide, benzoic acid, 4-chlorobenzoic acid, 3,4-dichlorobenzoic acid, 4-methoxybenzoic acid, 3,4-dimethoxybenzoic acid, 2-hydroxybenzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid and 4-nitrobenzoic acid dissolved in cyclopentanol at 298.15 K. Results of experimental measurements, combined with published solubility data and activity coefficient data taken from the published literature, were used to derive Abraham model correlations for solute transfer into anhydrous cyclopentanol solvent from both water and from the gas phase. The derived Abraham model correlations back-calculate the observed experimental data to within 0.11 log units (or less). [ABSTRACT FROM AUTHOR]

Coal and gas outburst (CGO) is one of the most devastating disasters in underground coal mines, and it always triggers substantial casualties and property losses. Therein, the coal seam permeability and gas extraction rate are usually low in tectonic coal reservoirs, threatening safe coal production activities. In this work, water-gas combined methane control technology was proposed, based on the merits of hydraulic fracturing (HF) and liquid CO2 phase change fracturing (LCPCF), to improve the permeability of tectonic coal reservoirs. A field experiment was then conducted in a coal seam near a fault to verify its technical practicality, and the tectonic coal seam gas governance effect was accordingly evaluated. The research results suggested that the maximal concentration and average concentration of a single drill hole after HF increased by 13 times and 3 times, respectively, while the maximal flow and average flow increased by 23.4 times and 24.7 times, respectively. On the other hand, the peak concentration and mean concentration of a single hole after LCPCF increase by 2.7 times and 3 times, respectively, and the peak flow and mean flow increase by 6 times and 6.6 times, respectively. Additionally, the destructive degree triggered by LCPCF can be intuitively quantified through grayscale analysis. Furthermore, through the application of water-gas combined methane control technology in engineering practice, the gross quantity of extracted gas is 11 times larger than when LCPCF or HF is individually conducted, and the mean concentration and flow are 1.9 times greater and 2.1 times greater, respectively, than when LCPCF or HF is separately performed, indicating that this technology is practical and has a superior tectonic coal seam permeability improvement effect. This study has profound implications for enhancing coalbed methane (CBM) recovery and for eliminating CGO disasters in tectonic coal reservoirs or complex geologic structure areas. [ABSTRACT FROM AUTHOR]

Reservoirs with gas cap and edge water grow rapidly in the early stage of development, the oil well has no water, the recovery period is short, the three phases of oil, gas, and water are easy to cross each other, the production decreases rapidly, and the development is difficult. Therefore, it is necessary to clarify the migration law of oil, gas, and water three-phase interface, find out the distribution law of remaining oil, and put forward the direction of EOR. In order to study the migration law of oil, gas, and water three-phase interface in the development of this kind of reservoir, taking JZ25-1S gas cap edge water reservoir as an example, a three-dimensional physical model is established based on the similarity criterion. The characteristics of fluid interface migration and the distribution of remaining oil under depletion development and barrier waterflood development are studied through experiments. The research results show that gas channeling occurs after 30 minutes of depletion development, and the migration speed of the oil-gas interface is faster than that of the oil-water interface, and the migration speed of the high-permeability layer is faster. The remaining oil in the low-permeability layer is mainly distributed on both sides of the oil and gas and oil-water channels, and the remaining oil in the high-permeability layer is mainly composed of rock particles, pore walls, and surfaces of interstitial materials. The ultimate recovery rate of depletion development is 25%. At the barrier waterflooding development for 60 minutes, gas began to appear, the migration rate of oil-gas and oil-water interface was stable, and the shape of fluid interface was gentle. A small amount of remaining oil in each permeability layer is distributed in the oil ring and gas cap area, and the distribution of remaining oil is mainly affected by injection timing and injection-production ratio. The final recovery rate of barrier waterflooding development is 51%, which is 26% higher than that of depletion development. The findings of this study can help for better understanding of great significance to the formulation of production parameters for depleted development of gas cap and edge water reservoirs and the implementation of later production stimulation measures. [ABSTRACT FROM AUTHOR]

Two-dimensional gas chromatography (2D GC)–quadrupole time-of-flight mass spectrometry (QTOFMS) combined with derivatization was applied to determine naphthenic acids (NAs) in oil sand processed water (OSPW). Using the excellent resolution of 2D GC and mass resolution of QTOFMS with derivatization, 8 cyclohexane carboxylic acid isomers, 18 methylcyclohexyl carboxylic acid isomers, and 18 methylcyclohexyl acetic acid isomers were identified. Linear relationships across wide concentration ranges were established with correlation coefficients (R2) of 0.9995, 0.9992, and 0.9990, for cyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, and 4-methylcyclohexane acetic acid. The precision, expressed as the relative standard deviation (RSD, n = 5), was from 7. 7–9.5% with recoveries between 72.0% and 84.9%. This method was applied to analyze sewage and showed high concentrations of naphthenic acids in untreated samples. [ABSTRACT FROM AUTHOR]

Aqueous phase trapping (APT) is a kind of mechanical formation damage, which occurs in tight sandstone gas reservoirs. The occurrence of APT has a dramatically adverse effect on the productivity of gas wells due to the decrease of water saturation and gas permeability near wellbore. In this research, a spontaneous imbibition experiment was carried out. The Lucas–Washburn model was used to describe the imbibition behavior. Then, a mathematical model of release judgment conditions was established based on the imbibition model, taking the threshold pressure gradient into consideration. Finally, combined with the two-phase flow mechanism of gas and water, the release time of APT was deduced. This model was used to calculate the releasing time of APT in actual producing wells, and the difference between the actual release time and predicted release time is only 0.1%, which indicates that the model established in this paper can be applied to predicting release judgment condition and release time in tight sandstone gas reservoirs precisely. The proposed model along with the findings of this research can pave the way for the continuous development of water breakthrough wells in tight sandstone gas reservoirs. [ABSTRACT FROM AUTHOR]

In flats where there are gas water heaters, there is waste of water at the beginning of a shower due to the large lengths of pipes between the showerheads and heater. This paper analyses the financial feasibility of implementing an automated system that saves such water. This paper also shows how the system prevents such waste. In six flats, by collecting cold water at the beginning of a hot shower, it was observed that 9.28 litres of water are wasted until the water temperature reaches 30°C. A financial analysis was performed based on costs and the amount of water that would be saved. It was considered the installation of the system in one or two showerheads per flat for multi-family buildings of different heights. The installation of one or two systems per flat would lead to savings of, respectively, at least 2.13 litres and 4.14 litres of water per shower. [ABSTRACT FROM AUTHOR]

In this study, we numerically investigated the effects of CO2 gas in geothermal water and the scale deposition formed in the wellbore on the flow characteristics. Geothermal water that contains CO2 gas has the potential to produce calcite scale deposits in the wellbore. To prevent scale formation, scale inhibitor is injected below the flash point in the wellbore, which is a challenging job. Therefore, using a wellbore simulator to predict the depth of flash commencement and the effects of scale deposition above the flash point on flow characteristics is important. In our numerical simulations, we changed the values of the CO2 gas concentration to study its effect on the flow characteristics. The simulation results show that the presence of CO2 increases the flash pressure relative to that of pure water. A higher CO2 gas concentration in the water will initiate flashing at a lower depth than a lower CO2 concentration. However, when the presence of scale deposits in the wellbore is taken into account, the calculated wellhead pressure is lower than that in a wellbore without scale deposition. [ABSTRACT FROM AUTHOR]

Reducing the ship's drag is an effective technique for reducing emissions, operating expenses, and improving EEDI. For slow-moving vessels, frictional resistance has been reported to contribute up to 80% of total resistance, demanding a thorough investigation in reducing it. Air or the gas has been used as a lubricant, to reduce the frictional resistance known as Micro Bubble Drag Reduction, which is the need of a present era. In this paper, the current research scenario on the technique is presented, which suggests a plausible reduction in frictional resistance of 80% for ships. The review suggests that reduction in drag depends on void fraction, coalescence and breaking of injected bubbles, the salinity of water and type of gas used, depth of water in which the bubbles are injected, and of course, on the location of injection points. In the end, recommendations have been provided to improve the drag reduction. [ABSTRACT FROM AUTHOR]

Owing to their high intrinsic properties, limestone fines (LF) seems to be a good replacement material of cement and/or sand, elaborating thus a new concrete without affecting its performances and properties. The present work aims at using, however, this natural material as an alternative cement or sand replacement, and investigating its influence on self-compacting concrete (SCC) properties at fresh and hardened states. Achieving this, several parameters have been examined, in terms of compressive strength, water permeability, chloride-ion penetration, gas permeability, water porosity and sorptivity. A total of 11 SCC mixes samples have been produced in two series, each one with different rate substitution (0%, 5%, 10%, 15%, 20% and 25%) of sand and cement. Our experimental data revealed the incorporation of LF up to 20% in SCC as partial replacement of sand and cement at fresh state, led to appreciable properties results. Nevertheless, at hardened state, at 15% for sand replacement an increase in compressive strength and a decrease in the water and chloride-ion diffusion, while an increase in the gas diffusion has been registered. And for cement replacement at 5%, an improvement in compressive strength and chloride ions diffusion was noted, whereas the water permeability and the gas diffusion decreased at 15% of LF substitution, where these results are widely discussed and explained in this paper. [ABSTRACT FROM AUTHOR]

This study aimed to compare the antibacterial effect of ozonated water and ozonated gas at different concentrations and exposure times. Staphylococcus aureus and Enterococcus faecalis were exposed to ozonated water or ozonated gas at concentrations of 20, 40 and 60 μg/mL for 1 and 2 minutes. A positive control with bacteria and a chlorhexidine 2% negative control were used. The number of colony-forming units (CFU/mL) was evaluated. The concentrations of 40 and 60 μg/mL were significantly more effective. For the E. faecalis, ozonated gas was significantly more effective than ozonated water. When compared to controls, all ozone concentrations were effective in reducing bacteria. [ABSTRACT FROM AUTHOR]

Drought and salinity are the two major abiotic stresses limiting barley growth and productivity. In order to understand the physiological and biochemical traits associated with deficit irrigation using saline water in barley at heading stage, this study was performed under field conditions to treat two barley landraces, "Karkeni" (origin: irrigated) and "Bengardeni" (origin: rainfed in arid area), with three irrigation treatments as a function of cultural evapotranspiration ETc (T0: 100% ETc, T1: 75% ETc and T2: 50% ETc). In both barley landraces, deficit irrigation with saline water (T1 and T2 treatments) significantly decreased net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), K+ content, K+/Na+ ratio and grain yield (GY); by contrast, DPPH and ABTS scavenging capacities as well as Na+ content were increased, concomitant with a landrace-dependent variation in phenolic compounds composition. Interestingly, under T1 and T2 treatments, "Karkeni" had the lowest A, E, gs and K+/Na+ ratio, and the highest Na+ content and GY. Overall, at heading stage, salt accumulation in deficit irrigated soils with saline water significantly reduces GY of barley by influencing gas exchange, phytochemical profiles and antioxidant activities, in a landrace-dependent manner. [ABSTRACT FROM AUTHOR]

Domestic hot water production is responsible for a significant part of domestic energy consumption; instantaneous gas heating devices are widely used because they don't require reservoirs, therefore have a competitive use/consumption ratio compared to other technologies. However, users' perception of comfort is severely affected by sudden changes in temperature outside the desired temperature. The instability of the water temperature with overshoots and undershoots is the most common disadvantage, which occurs mainly due to sudden changes in the water flow requested by users and the response delays inherent to the heating system. Traditional heat cell power controllers have difficulties in responding to these problems in a timely manner, as they don't have the capacity to anticipate the effects of sudden variations in water flowrate. In this work, predictive control strategies were developed which, due to its predictive nature, allows anticipating and correcting the negative effects of sudden variations of water flowrate in the temperature. A comparative analysis of model based predictive controllers (MPCs), with and without adaptive function, with traditional controllers used in the tankless gas water heaters (TGWHs) was carried out. Tests in a simulated environment demonstrated better performances in the stabilization of temperature during sudden changes in water flowrates. [ABSTRACT FROM AUTHOR]

Two objectives are targeted with this experimental study carried out on a granite heated up to 600 °C. The first one is to evaluate the coupled effects, on permeability and poromechanical properties, of the thermal treatment followed by three kinds of cooling (slow process in the oven or in the air and quick process in cold water). The second objective was to analyse the efficiency of the experimental procedure carried out to make the measurements, i.e. the use of inert gas or water to control the pore pressure. The use of gas clearly leads to more accurate observations than with water. It is especially true on the effects of confining pressure on permeability. A micro-cracking process goes along with the heating and is amplified by the thermal shock. This leads to high increase in permeability, which becomes more and more sensitive to the confining pressure. This is confirmed by the decrease in the drained bulk modulus Kb, in the expansion coefficient H and the increase in the Biot's coefficient. [ABSTRACT FROM AUTHOR]

It is of great significance to develop water-gas shift (WGS) catalyst with high catalytic activity in low-temperature operational regime. In this paper, we have prepared Cu confined in TiO2 nanotubes (TiO2NT, Cu-in-TiO2NT) catalyst via a vacuum-assisted impregnation method and subsequent calcination. The confined Cu-in-TiO2NT catalyst exhibits the higher CO conversion and H2 production rate than that of the Cu loaded on TiO2NT catalyst throughout the entire reaction temperature range. At the reaction temperature of 250°C and 300°C, the CO conversion of the confined catalyst is twofold and fourfold, respectively, higher than that of the supported catalyst, demonstrating superior catalytic activity toward WGS reaction. Due to the confinement effect of TiO2NT, the confined Cu-in-TiO2NT catalyst can enhance the concentration of the oxygen vacancies for H2O activation, contributing to the higher WGS activity. [ABSTRACT FROM AUTHOR]

CO2 injection and water-alternating-gas injection are EOR methods for improving oil recovery. This paper shows Water alternating gas (WAG) and continuous gas injection experiments with CO2 in secondary recovery. Experiments were performed in sand-packed-model. The continuous gas injection experiments were conducted at 3800, 4200, 4600 and 5000 psi, then two WAG experiments was completed at 3800 psi. Also temperature was 190 °F (the reservoir temperature) in all experiments. Six tests were conducted to investigate continuous CO2 and WAG injection under the reservoir condition. In the first test, 1.2 PV (pore volume) of CO2 was injected into sand-packed-model at pressure of 3800 psi and temperature of 190 °F. Amount 1.2 PV of CO2 was injected into sand-packed-model at 4200 psi in the test 2. In third one, 1.2 PV of CO2 was injected at 4600 psi and 1.2 of PV CO2 was injected at 5000 psi in forth one. Water alternating gas injection experiments with CO2 were including two tests. In the first one, 0.3 PV of CO2 and 0.9 PV of brine were injected consecutively into model. In the second one, 0.3 PV of CO2 and 0.3 PV of brine were injected respectively into model and this test was completed in two cycles. The results indicate that increase of injection pressure enhances oil recovery in continuous CO2 injection and increase of injected CO2 increases oil recovery in WAG process. Also WAG injection increases oil recovery more than CO2 continuous injection. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) are widely used in products related to human health. Thus, providing an optimum storage condition to preserve their quality and stability is very important. The effects of various duration and storage conditions on lavandin (Lavandula × intermedia L.) EO was investigated as used the raw material of aromatherapy and health products. The watery and dehydrated samples were stored in laboratory temperature (24±2°C), refrigerator (+4°C) and freezer (-18°C) for 100 and 200 days. Also, a sample of watery and a sample of dehydrated EO were exposed to air at laboratory temperature. GC/FID-MS analyses were performed to determine the variations in the components of the stored EOs. Linalool (39.49-45.81 %) was the major component in all samples. The other main components were camphor (9.95-14.68 %), borneol (8.77-12.45 %), 4-terpineol (6.12-9.51 %), 1,8-cineole (1.27-6.79 %), linalyl acetate (3.45-4.02 %), cis-linalool oxide (0.30-4.39 %) and trans-linalool oxide (0.19-4.03 %). Due to the evaporation and conversion processes, most of the components had a decreasing or increasing tendency during the storage period. Also, components such as α-pinene, camphene, β-myrcene, γ-terpinene, α-terpinolene, trans-sabinene hydrate and D-carvone disappeared during the oxidation process. Based on observations, storage time and temperature, water presence, atmospheric gases and possibly light had destructive effects on the concentration of lavandin EO components. It can be estimated that the molecular weight, molecular structure and boiling point caused the oscillation of lavandin EO constituents under various storage conditions. According to the findings, the best storage conditions for lavandin EO were low temperature and the absence of atmospheric gases and water. [ABSTRACT FROM AUTHOR]

The paper essentially deals with the stratospheric distribution of methane (CH4) over the Indian region, based on satellite-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) data as observed during 2003–2012 period. The inter-dependence of CH4 and other trace gases such as Water vapour (H2O), Ozone (O3), and Nitric oxide (NO), variation of the equivalent water and long-term trends in CH4 and H2O is also presented. The CH4 mixing ratio exhibits significant latitudinal and altitudinal dependence. The mixing ration of CH4 varies in the range that goes from [1.8, 2.1] Part per Million by Volume (ppmv) to [1.2, 1.4] ppmv in the upper troposphere to the lower stratosphere. An out of phase relationship is observed between CH4 and H2O in the stratosphere in all the three-latitude regions (0° to 10° N, 10° to 25° N, and 25° to 40° N) addressed in this analysis. It is estimated that about 2.7 molecules of H2O are produced as a result of oxidation of CH4 and the excess in H2O molecules is attributed to other production photochemical process, most important one being the oxidation of H2. The dependence of CH4 to O3 and NO is altitude dependent, exhibiting an exponential decrease in the lower stratosphere and linear relation in the upper stratosphere. The analysis of the equivalent water in the mid-stratosphere shows an irregular variation in the altitude of 23–35 km and a gradual increase as the height increases. The overall change in equivalent water in the stratospheric region is [1, 2] ppmv. No consistent trend is observed in stratospheric CH4. On the other hand, H2O depicts an overall increase. [ABSTRACT FROM AUTHOR]

Deep-sea hydrothermal source investigation utilising water and gas samples to characterise ocean resources requires water sampler, both large and small volume. How to preserve the original captured samples in the sampler during its lifting process to the surface remains challenging. Our research develops a piston type deep-sea pressure equaliser installed in the sampling bottle to solve the pressure problems using pressure self-adaptive principle. This paper describes a new mathematic analysis of the pressure equaliser and carries out its numerical computation accordingly. Two different scenarios i.e. sampling water only and sampling water as well as gas, are selected to evaluate the performance of this pressure equaliser. The result shows that this pressure equaliser is capable of adjusting the pressure properly in the lifting process of the deep-sea water sampling bottle and thus helps to secure the sampling quality. Therefore, the design of pressure equaliser is acceptable. [ABSTRACT FROM AUTHOR]

In this work, the efficiency of CO2-foam injection for enhanced oil recovery (EOR) is investigated. Six floods were performed on sand pack columns. Pure water injection, WAG injection and simultaneous injection of CO2 and surfactant solution with various concentrations were conducted. Notable difference was observed between oil production in secondary surfactant assisted WAG and other injection scenarios. The experimental work in this research shows that increase in concentration of surfactant in the injection process results in mobilization of more oil that may not have been achievable by using water flooding and WAG flooding methods individually. [ABSTRACT FROM AUTHOR]

Experimental solubilities have been measured at 298.15 K for benzil, biphenyl, pyrene, fluoranthene, acenaphthene, xanthene, fluorene, 1,2,4,5-tetramethylbenzene, 4-tert-butylbenzoic acid, benzoic acid, 4-chloro-3-nitrobenzoic acid, 4-methoxybenzoic acid, 3,4,5-trimethoxybenzoic acid, 3-methyl-4-nitrobenzoic acid, 4-aminobenzoic acid, diphenyl sulphone, 2-ethylanthraquinone, thioxanthen-9-one, thianthrene, o-acetoacetanisidide, sorbic acid, 1,4-dichloro-2-nitrobenzene, 1,4-dibromobenzene, salicylamide, benzoin and trans-stilbene. Results of experimental measurements were combined with published solubility data taken from the published literature to derive Abraham model correlations for transfer of solutes into 2-methyl-1-butanol. The reported Abraham model correlations describe the observed solute transfer coefficients to within an overall average standard deviation of approximately 0.08 log units. [ABSTRACT FROM AUTHOR]