Gasoline Hydrocarbons Research Articles

Reduction of losses of the initial n-hexane reactant with commercial isomerizate

The isomerization processes of paraffin hydrocarbons ensure a reduction in the content of aromatic and low-octane hydrocarbons in gasoline. The octane number of the commercial isomerizate used in compounding in gasoline depends on the clarity of separation of the components of the isomerization reaction mass, in particular, the presence of non-converted reactants in it leads to a decrease in the octane number and loss of these raw material components. The commercial isomerization unit of a typical low-temperature isomerization unit of the light gasoline fraction PGI-DIG, together with the target products, contains low-branched and raw normal hydrocarbons, in particular, n-hexane is present, which degrades the quality of the commercial isomerization due to its low octane number (OCI= 25). One of the flows of the technological scheme forming the commercial isomerizate from the installation is the cubic product of the deisohexanizer column, the content of n-hexane in which is up to 3.5% by weight. Therefore, in industrial conditions it is advisable to extract it from the cubic product of the deisohexanizer with subsequent recycling into the raw material stream. The paper proposes a change in the technological scheme of the low-temperature isomerization installation in order to reduce the loss of raw hydrocarbons with commercial isomerization by including an additional Kdop distillation column in it. The research was carried out using the Unisim Design modeling program. The calculations performed have obtained appropriate technological modes of operation and structural parameters of the Kdop column: the number of single-flow valve plates is 30, the pressure in the Rniz column = 160kPa and Rvc = 110kPa, the temperature in the reboiler and condenser is 102.4 and 81.3 ℃, respectively, the phlegm number R = 2.5. The inclusion of an additional Kdop distillation column in a typical technological scheme ensures a reduction in losses of n-hexane with commercial isomerizate by 1.78% while simultaneously increasing its octane number by up to 2.4 points.

Effects of several typical plastic combustion residues on gasoline

Abstract In order to solve the interference caused by polymer materials on gasoline accelerants in arson cases, the characteristics of residues after combustion of some typical plastics are studied. Comparing it to the combustion residue of gasoline, we discussed the interference in gasoline detection. The results show that the combustion products of these plastics mainly interfere with the alkanes and aromatic hydrocarbons in gasoline. Polyethylene, polystyrene, and polyvinyl chloride mainly produce C9-C16 branched-chain and straight-chain alkanes. Polystyrene and ABS resin generated C5 and C6 alkanes, also generated C1-benzene, C2 - benzene, and styrene. It mainly affects the identification of aromatic hydrocarbons in gasoline combustion residues. Understanding the types and characteristics of products in the combustion residues of these plastics can provide powerful evidence for fire investigators and criminal technicians in physical evidence identification.

Improvement of the technological scheme of the installation of low-temperature isomerization of light gasoline fraction

The isomerization processes of paraffin hydrocarbons ensure a reduction in the content of aromatic and low-octane hydrocarbons in gasoline. The octane number of a commercial isomerizate largely depends on the clarity of separation of the components of the isomerization reaction mass and the degree of recirculation of non-converted paraffin hydrocarbons of normal structure. The reaction mass of the technological installation for low-temperature isomerization of the light gasoline fraction PGI-DIH, together with the target products, contains low-branched and normal hydrocarbons, in particular, up to 12% by weight of n-pentane is present in the industrial isomerizate, which degrades the quality of the commercial isomerizate due to its low octane number (RON=61.7). One of the flows of the technological scheme forming the isomerizate flow from the installation is the distillate of the deisohexanizer column, the content of n-pentane in which is up to 14.6% by weight therefore, in industrial conditions, it is advisable to extract it from the distillate of the deisohexanizer with subsequent recycling into the raw material stream. The paper proposes a change in the technological scheme of a low-temperature isomerization installation in order to maximize the extraction of raw hydrocarbons from a stable isomerizate by including a system of two additional distillation columns Cadd and DP. The research was carried out using the Honeywell Unisim Design modeling program. The calculations performed show the appropriate technological modes of operation and structural parameters of the columns: the Cadd column contains 61 three-flow valve plates, the pressure in the column Pbot = 245kPa and Ptop = 196kPa, the temperature Treb = 81.7 °С and Tcond = 47.9 °С; the DP column has 60 two-flow valve plates, the pressure Pbot = 400kPa and Ptop = 200kPa, temperature Treb = 83.4 °С and Tcond = 45.5 °С. The proposed technological scheme provides almost complete extraction of n-pentane (99.9% by weight) from a stable isomerizate with a simultaneous increase in its octane number by 2 points.

Study of electrochemical remediation of clay spiked with C12-C18 alkanes

To date, the management of polluted soils and sediments is challenging because they can be characterized by heterogeneous conditions, miscellaneous contaminants (organic and inorganic ones), fine grains and low-hydraulic permeability. In these cases, the current treatment methods are poorly effective. ElectroChemical Remediation Technologies (ECRTs) are considered some of the main appealing strategies for the remediation of such complex sites. The ECRTs are based on the application of a relatively low cell potential value, between two or more electrodes, inducing an electric field (E) through the polluted media, which prompts the remediation of the contaminated site. This work was focused on the study of the electrochemical remediation of kaolin artificially spiked with a miscellaneous of five alkanes (C12H26, C13H28, C14H30, C16H34, C18H38), namely C12-C18. Kaolin was selected as a model reproducible, low-buffering, and low-permeability clay and the mixture C12-C18 as a hazardous model of petrol hydrocarbon compounds. The effect of several operative conditions, including the E intensity, type of technology, presence of supporting electrolyte, was investigated. It was found that adopted low E values can simultaneously mobilize and degrade in situ the C12-C18 mixture and that the shorten the chain compound, the easier the remediation efficiency, R. It was shown that the usage of E of approximately 0.50 V cm−1 allows to reach a total C12-C18 removal (R(C12-C18)) of ∼70% after 96 h. Finally, it was demonstrated that the usage of sodium chloride improves the performances of the process: R(C12-C18) increased from 61 to 83% when NaCl was added.

Systematic construction of combustion reaction model for large hydrocarbon fuels based on a two-step reaction scheme

Understanding the combustion chemistry of large hydrocarbons in practical gasoline, diesel and jet fuels is critical for the reduction of pollutant emissions and increase of fuel and engine efficiencies. The primary objective of the present study is to illustrate the methodology and application of a simplified modeling approach based on a two-step reaction scheme (TSRS) for describing the combustion chemistry of large hydrocarbon fuels under engine-relevant high-temperature conditions. Under such conditions, the combustion process of large hydrocarbons consists of two distinct subsequent reaction steps: the first step is the prompt fuel decomposition, converting the parent fuel to critical intermediate products; the second step is the oxidation reactions of the intermediates. Particularly, the second step is slower, thus rate-limiting, controlling the heat release and formation of final combustion products of the entire combustion reaction process. A systematic analysis by mathematical methods was performed to obtain a unified treatment for hydrocarbons with different molecular sizes. Based on the analysis of characteristic time scale of elementary reaction and steady-state assumption, TSRS used a fuel decomposition submodel to describe the fuel molecule decompose into critical intermediate species, including ethene, propene, butenes and methane for n-alkanes, and used a detailed foundational fuel chemistry mechanism to describe the oxidation reaction of the intermediates. The entire TSRS reaction model for large hydrocarbons is compact, consisting ∼110 species and ∼800 reactions, which can be further reduced. It was shown in the present study that, by revealing the relationship between the functional group composition of linear alkanes and the distribution of intermediates, and in combination with the rate criterion, the fuel decomposition submodel can be systematically generated to facilitate the automatic construction of compact kinetic models. One unified TSRS combustion reaction model was created and demonstrated for several large hydrocarbons ranging from C8 to C16, which was validated by comprehensive datasets, including speciation, ignition delay times and laminar flame speeds.

Enhanced methanol to gasoline performance using nanosheet-like SAPO-11 catalyst

Herein, spherical and nanosheet-like SAPO-11s were successfully synthesized hydrothermally and utilized to catalyze the methanol-to-gasoline (MTG) process. The nanosheet-like SAPO-11 (SAPO-11-A) had a thickness of about 10 nm, while the spherical SAPO-11 (SAPO-11-B) had a particle size of around 11 μm. Compared to SAPO-11-B, the property of SAPO-11-A was enhanced by 42.9% in specific surface area (SSA), 38.1% in mesopore volume (Vme) and 20.2% in acid amounts, respectively. In terms of catalytic performance during the MTG reaction, SAPO-11-A demonstrated superior results not only in the methanol conversion (95.82%), gasoline-range hydrocarbons selectivity (58.76%) and iso/nparaffin ratio (8.17) but also in suppressed coke deposition (2.56%) compared with those (90.63%, 50.95%, 4.75 and 5.73%, respectively) of SAPO-11-B. Additionally, the optimal MTG process conditions were identified utilizing SAPO-11-A, demonstrating a methanol conversion rate of 98.34%, a gasoline hydrocarbon selectivity of 67.61%, an isoparaffin selectivity of 36.01% and an iso/nparaffin ratio of 10.94 at 380 °C, weight hourly space velocity (WHSV) of 2 h−1 and 1 MPa. These results highlight the potential of nanosheet SAPO-11 to produce gasoline-range hydrocarbons rich in isoparaffins.

Enhanced conversion of syngas to high-quality gasoline hydrocarbons over ZnZrOx coupled SAPO-11 nanosheets bifunctional catalyst

Syngas is a key precursor for synthesizing gasoline (C5-C11) hydrocarbons, offering an efficient route for utilizing non-petroleum carbon sources. However, the conventional Fischer-Tropsch synthesis (FTS) process faces a constraint with a maximum 45% selectivity for C5-C11, attributed to the Anderson-Schultz-Flory (ASF) distribution. Herein, bifunctional catalysts comprising ZnZrOx with different Zr/Zn ratios along with SAPO-11 zeolite sieves featuring varied morphologies like nanosheets (SA-A), petals (SA-B), and spheres (SA-C) have been effectively formulated and employed for the syngas-to-gasoline hydrocarbons (STG) reaction. Notably, the selectivity toward C5-C11 far exceeded the ASF limits. Under identical reaction parameters, the Zn1Zr4Ox/SA-A catalyst demonstrated notable enhancements of 6.6% and 26.2% in CO conversion, along with 4.6% and 7.6% increases in C5-C11 selectivity, as compared to that of Zn1Zr4Ox/SA-B and Zn1Zr4Ox/SA-C catalysts, respectively. Furthermore, under the ideal conditions (380 °C, 4.5 MPa and gas hourly space velocity (GHSV) of 2400 mL min−1 g−1), Zn1Zr4Ox/SA-A exhibited an exceptional C5-C11 selectivity of 69.8% (CO2-free) alongside a single-pass CO conversion of 30.4%. Impressively, isoparaffin constituted 39.2% of the total composition, with the iso/n-paraffin ratio reaching 11.8. Even after 100 h, the catalyst maintained its remarkable catalytic activity, with the CO conversion and C5-C11 selectivity maintaining levels of 27.5% and 66.85%, respectively.

Reactive adsorption desulfurization of FCC gasoline over self-sulfidation adsorbent

NiSO4/ZnO-Al2O3-SiO2 adsorbent, as a novel reactive adsorption desulfurization (RADS)adsorbent, has self-sulfidation ability and high desulfurization performance when treating model fuel. However, the RADS performance of the adsorbent under FCC gasoline feedstock is not well understood. Here, we compare the performance of the adsorbent under FCC gasoline with model fuel to test the effect of the hydrocarbon composition of the feedstock. The complex composition of FCC gasoline makes it sensitive to the nickel loading amount of the adsorbent. Under the influence of specific surface area and pore structure, the adsorbent loaded with 3 wt% nickel shows better desulfurization activity when treating FCC gasoline. As hydrocarbons in FCC gasoline compete with sulfur compounds for active Ni sites, the reaction conditions have been tested and optimized to achieve deep desulfurization while maintaining low olefin loss to ensure the octane number of the product. By experimental tests and characterization, it has been proved that NiSx and NiO acted as active Ni sites of the adsorbent. Based on these observations, the mechanism of RADS of FCC gasoline over NiSO4/ZnO-Al2O3-SiO2 adsorbent has been proposed, which provides theoretical support for the development of new adsorbents and the optimization of RADS process.

Dolomite catalyst for fast pyrolysis of waste cooking oil into hydrocarbon fuel

Dolomite as the catalyst for pyrolysis of waste cooking oil (WCO) was investigated to produce hydrocarbon fuels. Optimization of pyrolysis parameters i.e. time, temperature and catalysts loading, achieved high selectivity of WCO to diesel hydrocarbon, compared to thermal pyrolysis that produced mainly carboxylic acids. Dolomite catalysed deoxygenation of fatty acid in WCO into hydrocarbon, consequently accelerating the pyrolysis time to 75 min. Bio-oil at 68.06% yield with 57.27% selectivity towards diesel and gasoline hydrocarbons was obtained at 450 °C while using 6% of dolomite. Dolomite exhibited partial phase separation into dolomite/CaCO3 mixtures within 15 min of pyrolysis, initiated by the generated CO2 during pyrolisis of WCO. The catalyst is stable for up to three reaction cycles suggesting the activity was achieved from the synergy between the dolomite/CaCO3 phases.

STUDY OF THE INFLUENCE OF HEAVY OIL RESIDUES ON THE YIELDS OF CATALYTIC CRACKING PRODUCTS

The results of the study of the process of catalytic cracking of fuel oil on a microspherical zeolite-containing catalyst showed that the cracking of a mixture consisting of hydrotreated vacuum gas oil (85% by weight) and sulfurous fuel oil (15% by weight) leads to an increase in the yield of catalytic distillate by 5.4 – 7.7% by weight, for a mass feed rate of 2 and 4 hours 1, respectively. At the same time, there is a change in the output of all distillate components compared to their output from pure vacuum gas oil. A decrease in coke deposition on the catalyst by 1.9 – 2.6% by weight and an improvement in the quality of the products obtained were found. The content of sulfur and unsaturated hydrocarbons in gasoline obtained from hydrotreated raw materials is less, aromatic compounds are more. Light and heavy gas oils also contain significantly less sulfur. These studies will deepen the oil refining process, increase the yield of catalytic distillate and reduce the environmental burden.

One-Step Carbothermal Reduction Synthesis of Metal-Loaded Biochar Catalyst for In Situ Catalytic Upgrading of Plastic Pyrolysis Products

A novel biochar-supported metal catalyst was prepared in this study using a one-step carbothermal reduction synthesis method for the catalytic pyrolysis of plastics. Several catalysts with different metals (Cu, Fe, Ni, and Ru) loaded on three biochar supports from lignin, soybean straw, and Chlorella vulgaris were evaluated using XRD, FTIR, NH3-TPR, and TEM. Zerovalent metal nanoparticles, including Ni, Cu, and Ru, and various functional groups were observed on the biochar surface. The chemical selectivities of gasoline hydrocarbons (C4–C12 hydrocarbons) reached 76.2% with a remarkable catalytic cracking effect of Ni/lignin biochar on low density polyethylene (LDPE). Catalytic performance was comparable to that of the Ru-based catalyst, which contributed to 85.6% of gasoline hydrocarbons. The Ni/lignin catalytic cracking of plastic waste simulated by LDPE, polypropylene (PP), and polystyrene (PS) showed a maximum selectivity of 87.9% for C4–C12 hydrocarbons and yields of 78.1 mg/g for benzene, toluene, and xylene (BTX). The mechanism related to the cleavage of long chain radicals of polyethylene, polypropylene, and polystyrene as well as the aromatization of aliphatics were proposed.

Preliminary Assessment of Occurrence, Potential Origin, and Human Health Risk of Volatile Organic Compounds in Uncontrolled Springs, North Morocco.

In recent years, with the drastic increase in worldwide pollution rates, considerable attention has been paid to the volatile organic compounds (VOCs) that might lead to serious health problems, e.g., cancer. As there appears to be a notable lack of research on the pollution (specifically, VOCs) of water bodies in Morocco, we aimed to assess the occurrence of VOCs in some uncontrolled springs in the north of Morocco that have not been previously investigated. We also discuss the estimation of health risks posed by ingestion and dermal contact as well as the different potential origins of these pollutants. For this purpose, water samples were collected from twenty-six sampling sites and were analyzed via headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Out of the 60 suspected VOCs, a total of 15 compounds belonging to five distinct groups were identified and quantified. Among them, fumigants, solvents, and gasoline hydrocarbons were the most abundant groups, with proportions of 40%, 26.7%, and 20%, respectively. A heatmap clustered the provinces based on their degree of pollution, while a dendrogram was used to classify the studied springs into six main groups. Regarding carcinogenic risk, all the samples were safe for consumption as well as for dermal contact, except for S17, S18, and S8, and S19, which might present a severe threat to inhabitants due to their contents of, respectively, naphthalene (2.1 × 10-3), chloroform (2.5 × 10-4), and cis and trans-dichlropropene (1.61 × 10-4 and 1.11 × 10-4). Our investigation revealed several anthropogenic sources of water contamination, which could aid authorities in limiting contamination spread in water bodies.

Nephrotoxicity of gasoline fumes in male albino rat: a mechanism-based approach study

Nephrotoxicity of gasoline fumes has been documented, but the mechanisms underlying the toxicity remain vague. This study determined the residue of gasoline components in the kidney of 72 male albino rats with a view to providing the basis for a detailed understanding of the nephrotoxicity of gasoline fumes. The rats were randomized into 6 groups and daily exposed to distilled water (control) or gasoline fumes for 1, 3, 5, 7 and 9 h for 10 weeks. Some standard clinical blood biochemistry, activities of some kidney antioxidant and membrane-bound ATPase enzymes and kidney histological changes were examined. Gasoline hydrocarbons were extracted, identified and quantified in the kidney of rats with Gas Chromatography-Mass Spectrometry (GC-MS). Significant (p < 0.05) changes were observed in the biochemical parameters examined in the blood and kidney of the exposed rats compared to the control. Residues of some gasoline metabolites including 2,3-diphenylcyclopropyl) methyl phenyl sulfoxide; Cyclotrisiloxane and 2.2-Paracyclophane were identified in the kidney of rats exposed to gasoline fumes. The kidney of the exposed rats also displayed mild histological changes. Retention of some hydrocarbons in the kidney of rats exposed to gasoline fumes could potentially result in oxidative stress capable of inducing renal dysfunction. Key policy highlights Continuous exposure to gasoline fumes for varying hours over a period of time may result in the retention of some gasoline hydrocarbons and metabolites in the kidney of the exposed animal. Presence of gasoline hydrocarbons and metabolites in the kidney may induce a high production of reactive oxygen species and consequently lead to oxidative damage to the organ. Metabolic process of gasoline hydrocarbons in the kidney of the exposed animal varies with the hours of exposure.

A molecular-level coupling model of fluid catalytic cracking and hydrotreating processes to improve gasoline quality

A molecular-level Fluid Catalytic Cracking (FCC)-Gasoline Hydrotreating (GH) process coupling model was established to guide the optimization of the hydrocarbon compositions in gasoline based on the Structure Oriented Lumping (SOL) method. 96 FCC reaction rules and 24 GH reaction rules were formulated, and a reaction network containing about 120,000 reactions was constructed. In order to establish the FCC-GH process coupling model, the effective transfer of composition information between the two processes was realized through the molecular composition matrix of gasoline. The molecular composition matrix of gasoline was obtained according to the classification rules of the molecular composition matrix of FCC products. The conversion laws of hydrocarbon molecules in gasoline were investigated by tracking their generation paths and reaction paths. The influences of reaction conditions on the distribution of hydrocarbons in the product gasoline could be calculated quantitatively by the FCC-GH process coupling model at molecular level.

Влияние поверхностной концентрации никеля на активность и селективность сорбентов Ni/ZnO-Al2O3 в реакционно-адсорбционном обессеривании олефинсодержащего сырья

The advantages of the reactive adsorption process for ultra-deep desulfurization of FCC gasoline and other hydrocarbon fractions are shown. To study the influence of the surface concentration of nickel on the reactive adsorption activity and selectivity, several Ni/ZnO-Al2O3 adsorption-catalytic systems with different nickel contents were synthesized. It has been established that at the chemisorption stage at a temperature of 400°C, a pressure of 0.5 MPa, and an weight hourly space velocity of 5.2 h–1 the thiophene conversion increases to 94.8% with a nickel surface concentration increase to 8 at/nm2. However, the maximum value of the hydrodesulfurization/hydrogenation selectivity factor is achieved for the Ni/ZnO-Al2O3 adsorption-catalytic system with a nickel surface concentration of 6 at/nm2.

Zeolite catalytic pyrolysis of waste tire into fuel in gasoline hydrocarbon range

The increasing production of automotive vehicles has led to a significant increase in the rate of waste tire generation. Approximately 160 tons/day of waste tire are produced in Bandung City which will eventually become an environmental problem. However, the pyrolysis process can be applied as a technology to treat waste tire to produce valuable hydrocarbon products. This study addressed the description effect of used tire waste on the yield, properties, and composition of tire pyrolysis oil (TPO) products. The effect of zeolite catalysts on TPO was also studied. 500 g of the waste tire was pyrolyzed using a small tube reactor containing a zeolite catalyst at various temperatures of 300-450 °C for 60 minutes. From the present work, the highest TPO product yield of 36.6 %-wt was obtained during the pyrolysis of the waste tire. The characteristics of TPO as a fuel, such as viscosity and density are close to those of gasoline fuel with a heating value of about 44 MJ/kg. The compounds contained in TPO were classified into hydrocarbon groups compounds as commercial fuel which are included as compounds of aromatics, paraffin, naphthenes, and cycloparaffins through the results of GC-MS spectrum analysis. The TPO from waste tire pyrolysis is on par with the hydrocarbon range of gasoline (C7-C11).

Numerical study on the blending of excellent anti-knock fuel using artificial neural network

In order to reduce emissions, the content of olefins and aromatic hydrocarbons in gasoline is required to be lower. The reduction of these two high-octane-number components increases the knock tendency of turbocharged engines, which limits thermal efficiency. Therefore, the optimization of the component proportion of gasoline in turbocharged GDI engines under the new gasoline standard is discussed in this paper. To blend the fuel with excellent anti-knock property, the influence of each component in the gasoline on the knock of turbocharged gasoline engine was analyzed by three-dimensional CFD simulation, and BP neural network was established based on a large number of data to predict the in-cylinder combustion of the fuels with different component proportion, which greatly saved the calculation cost. The results show that increasing of aromatic hydrocarbons and olefin in fuel can effectively improve the anti-knock property of fuel. Within the range of component proportion required by the Chinese gasoline standard specification, when the volume fraction of isooctane is 47%, n-heptane is 0, toluene is 35%, and diisobutylene is 18%, Pmax and MAPO value is the smallest, that is, the fuel has better anti-knock property.

Influence of sweet orange peel oil additive on physicochemical properties of gasoline

The effect of a sweet orange peel oil additive on fuel blends of low-octane gasoline was investigated. The additive contains limonene, β-myrcene, eugenol, and triacetin, which have characteristics resembling gasoline but with advantages in terms of molecular structure that can increase RON and produce a homogeneous mixture. The additive changed the molecular behaviors influencing the physicochemical properties of the fuel blends. The experiments were conducted using fuel blends with additive fractions of 0%–75% (v/v). The fuel blends were mixed manually in 50-ml volumes in closed beaker glasses under STP conditions. The physicochemical properties were then measured to evaluate the chemical molecular structure compositions, viscosities, densities, heating values, and RONs of the blends, to determine the effect of the fuel additive on engines.The results show that the additive compounds were able to change the molecular behaviors of the fuel blends. The fuel blends produced 50 hydrocarbon compounds from 32 pure gasoline hydrocarbon compounds, which influenced the physical properties of the blends. The viscosities, beyond the lowest value at approximately 1.8 cSt, exhibited an increasing pattern compared to the viscosity of base gasoline fuel. The density and heating values tended to increase, even though there were fluctuating values due to intramolecular force movement and differences in molecular dipoles in the fuel blends. The RONs of the fuel blends, with additive fractions of 1%, 5%, 10%, 25%, 50%, and 75%, increased to 88.2, 91.5, 92.1, 95.7, 103.9, and 120.45, respectively. The increase in RON was also affected by the additive components among the fuel-blend molecules, which reacted to form highly stable hydrocarbon molecules, particularly aromatic and branched hydrocarbons, that inhibited combustion at low temperatures. Therefore, sweet orange peel oil as an additive can improve the physicochemical properties of gasoline, and thus can be mixed with any commercial fuel, especially those with a low octane number. It can be used for engines that require standard physical and high-octane properties.

Guidelines for surfactant selection to treat petroleum hydrocarbon-contaminated soils

The present study determined the most effective surfactants to remediate gasoline and diesel-contaminated soil integrating information from soil texture and soil organic matter. Different ranges for aliphatic and aromatic hydrocarbons (> C6–C8, > C8–C10, > C10–C12, > C12–C16, > C16–C21, and > C21–C35) in gasoline and diesel fuel were analyzed. This type of analysis has been investigated infrequently. Three types of soils (silty clay, silt loam, and loamy sand) and four surfactants (non-ionic: Brij 35 and Tween 80; anionic: SDBS and SDS) were used. The results indicated that the largest hydrocarbon desorption was 56% for silty clay soil (SDS), 59% for silt loam soil (SDBS), and 69% for loamy sand soil (SDS). Soils with large amounts of small particles showed the worst desorption efficiencies. Anionic surfactants removed more hydrocarbons than non-ionic surfactants. It was notable that preferential desorption on different hydrocarbon ranges was observed since aliphatic hydrocarbons and large ranges were the most recalcitrant compounds of gasoline and diesel fuel components. Unlike soil texture, natural organic matter concentration caused minor changes in the hydrocarbon removal rates. Based on these results, this study might be useful as a tool to select the most cost-effective surfactant knowing the soil texture and the size and chemical structure of the hydrocarbons present in a contaminated site.

Numerical Study of Combustion Characteristics, Performance and Emissions of SI Engine Fueled with Different Hydrocarbons Fuels

A numerical approach has been designed and modified with Advanced Simulation Technologies Boost to examine the impact of the piston face temperature on the performance of the spark ignition engine, combustion characteristics and emissions when using liquefied petroleum gas (LPG) and petrol fuels at an engine speed of 2500 rpm with a constant throttle position. In this work, a four-cylinder four-stroke spark ignition engine was used. The results show that when the piston face temperature increased, the brake power and the effective torque were reduced. No alteration in the specific brake fuel consumption for both fuels selected at higher piston face temperature has been observed. The peak fire pressure decreases while the peak fire temperature grows slightly when moving from lower to higher temperatures on the piston face. Liquid petroleum gas produced lower effective power and an effective torque compared to the gasoline fuel at all the selected piston face temperature. For both fuels, carbon monoxide and NOx emissions increased, while unburned hydrocarbon emissions decreased dramatically when the temperature of the piston face increased. The LPG emitted lower exhaust gas emissions than the gasoline hydrocarbon fuel at all piston temperatures.