Diesel Hydrocarbons Research Articles

Determination of selected oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) in diesel and air particulate matter standard reference materials (SRMs)

Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) have recently received much attention in discussions regarding the negative impacts of particulate matter (PM) on human health and the environment. The National Institute of Standards and Technology provides several environmental matrix standard reference materials (SRMs) with certified and reference values for polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs. In this study, the concentrations of oxygenated PAHs are determined in three air PM SRMs (1649b, 1648a, and 2786) and three diesel PM SRMs (1650b, 2975, and 1975) using two independent gas chromatography-mass spectrometry methods. Concentrations of oxy-PAHs were at the milligrams per kilogram level with higher overall concentrations in diesel PM (up to 50 mg/kg for 9,10-anthraquinone). One of the highest oxy-PAH concentrations (up to 5 mg/kg) measured in the air particulate SRMs was for 7,12-benz[a]anthracenquinone. These results suggest that oxygenated PAHs should not be neglected in the analysis of PM as their concentrations can be as high as those of some PAHs and are one to two orders of magnitude higher than those for nitro-PAHs.

Effect of Pt Dispersion on the Catalytic Activity of Supported Pt Catalysts for Diesel Hydrocarbon Oxidation

The catalytic activity of Pt/Al2O3 for the total oxidation of hydrocarbon mixture of n-decane and 1-methylnaphthalene was strongly dependent on the Pt dispersion. The maximum hydrocarbon oxidation activity was achieved for Pt/Al2O3 with Pt dispersion (DPt) of 0.39. On the other hand, the activity of Pt/ZrO2 monotonously decreased with decreasing Pt dispersion from 1.00 to 0.09. In situ FT-IR spectroscopy suggested that the presence of plural Pt species in metallic state with slight different electric state, which well catalyze the formation of acrylate species as an intermediate, is responsible for the high catalytic activity of Pt/Al2O3 with DPt = 0.39.

A Multifunctional Converter for Purifying Diesel Exhaust Gas with a Self-Heat Exchange Function

As a continuation of our study of heat-integrated converters, we have fabricated a multifunctional converter that can treat all the components of emissions from diesel vehicles, namely CO, hydrocarbons, nitrogen oxides (NO x ), and particulate matter (PM). NO x is reduced over a NH3-SCR catalyst while PM is removed by a diesel particulate filter. The converter is also equipped with a self-heat exchanger that transfers heat from downstream to upstream of the converter, increasing the converter temperature and thereby substantially improving its performance. In an experiment using a 2.2-L engine vehicle operated at a constant speed of 60 km/h, the NO x and PM reduction rates respectively reached 98 and 99.97 % due to efficient heating of the exhaust gas from 117 to 320 °C in the converter by the addition of H2 in the exhaust gas combined with the self-heat exchange function. Under transient driving conditions (Japanese 10–15 mode), the total NO x reduction rate was 96 %.

Catalytic deoxygenation of microalgae oil to green hydrocarbons

Microalgae are high potential raw biomass material for triglyceride feedstock, due to their high oil content and rapid growth rate, and because algae cultivation does not compete with edible food on arable land. This review addresses first the microalgae cultivation with an overview of the productivity and growth of microalgae, the recovery of lipids from the microalgae, and chemical compositions of microalgae biomass and microalgal oil. Second, three basic approaches are discussed to downstream processing for the production of green gasoline and diesel hydrocarbons from microalgae oil, including cracking with zeolite, hydrotreating with supported sulfided catalysts and hydrodeoxygenation with non-sulfide metal catalysts. For the triglyceride derived bio-fuels, only “drop-in” gasoline and diesel range components are discussed in this review.

Radiation-thermal transformations and distillation of lipids and disperse systems on their basis

The radiation-thermal transformations of rape oil under conditions of postradiation distillation, radiation heating, and electron-beam distillation with auxiliary heating were studied. Diesel hydrocarbons were predominant in the condensate distilled off upon combined heating. The concentration of oxygen atoms decreased as a result of radiation-induced decarboxylation and dehydration processes. The irradiation of oil as a constituent of disperse systems facilitated purposeful deoxygenation, a decrease in the viscosity, and an increase in the yield of the gasoline fraction.

The Paleobiosphere: a novel device for the in vivo testing of hydrocarbon producing-utilizing microorganisms

The construction and testing of a unique instrument, the Paleobiosphere, which mimics some of the conditions of the ancient earth, is described. The instrument provides an experimental testing system for determining if certain microbes, when provided an adequate environment, can degrade biological materials to produce fuel-like hydrocarbons in a relatively short time frame that become trapped by the shale. The conditions selected for testing included a particulate Montana shale (serving as the "Trap Shale"), plant materials (leaves and stems of three extant species whose origins are in the late Cretaceous), a water-circulating system, sterile air, and a specially designed Carbotrap through which all air was passed as exhaust and volatile were hydrocarbons trapped. The fungus for initial testing was Annulohypoxylon sp., isolated as an endophyte of Citrus aurantifolia. It produces, in solid and liquid media, a series of hydrocarbon-like molecules. Some of these including 1,8-cineole, 2-butanone, propanoic acid, 2-methyl-, methyl ester, benzene (1-methylethyl)-, phenylethyl alcohol, benzophenone and azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl), [1S-(1α,7α,8aβ)]. These were the key signature compounds used in an initial Paleobiosphere test. After 3 weeks, incubation, the volatiles associated with the harvested "Trap Shale" included each of the signature substances as well as other fungal-associated products: some indanes, benzene derivatives, some cyclohexanes, 3-octanone, naphthalenes and others. The fungus thus produced a series of "Trap Shale" products that were representative of each of the major classes of hydrocarbons in diesel fuel (Mycodiesel). Initial tests with the Paleobiosphere offer some evidence for a possible origin of hydrocarbons trapped in bentonite shale. Thus, with modifications, numerous other tests can also be designed for utilization in the Paleobiosphere.

Diesel hydrocarbon oxidation over platinum on mesoporous silica doped with secondary component metals via a sol–gel methodology

The oxidation of diesel hydrocarbons over platinum supported on mesoporous silica doped with secondary component metals (Al, Zr, Ti, Ce, La, Ca, Mg) via a sol–gel technique was investigated. Pt/SiO2 had the lowest oxidation activity, exhibiting a conversion of only 75 % at 500 °C. In all cases, the catalytic activity of this material was significantly improved by doping with a secondary component metal. The observed order of improvement by metal, from highest to lowest, was: Al, Zr, Ti, La, Ca, Mg, Ce. Pt/Al–SiO2 and Pt/Zr–SiO2 in particular showed high activity with T 50 values of 203 and 220 °C, respectively. The materials with greater platinum dispersion and with more acidic sites exhibited higher activity. The effects of varying Zr content in the Pt/Zr–SiO2 catalyst were also investigated. Both platinum dispersion and the number of acidic sites were increased with increasing Zr content and catalytic activity was significantly improved, reaching a maximum at approximately 5 mol % Zr.

Sapium Sebiferum(Chinese Tallow), a Promising Energy Plant for Green Diesel(hydrocarbon Fuel）

Sapium Sebiferum is a multiple functional tree with application in energy, pharmaceutics, materials and sightseeing. China is the source land of Sapium Sebiferum. In this paper, the potential of establishing a Sapium Sebiferum based bioenergy industry clusters was discussed. Among all, preparing green diesel (hydrocarbon fuel) from Sapium Sebiferum oil seed via microwave assisted pyrolysis process is the key technology. An ambitious project was described, also foreground of this bioenergy-ecosystem remediation plan was estimated.

NANOSTRUCTURE OF RENEWABLE OXYGENATED FUELS PARTICULATE MATTER

This paper describes a part of an ongoing research project in diesel Particulate Matter (PM) reduction by using renewable oxygenated fuel. In order to achieve the particulate matter reduction, physical structure and aggregation behavior should be investigated for better understanding of designs and configurations of Diesel Particulate Filter (DPF). The nanostructures of diesel and biodiesel PMs were investigated by using a Scanning Electron Microscopy (SEM) and a Transmission Electron Microscopy (TEM) for better understanding. The primary size distributions as well as particulate structures were presented by means of scanning images. The average primary sizes of diesel and biodiesel fuels PMs are approximately 50-60 nm and 30-40 nm, respectively. The average carbon platelet sizes of diesel and biodiesel PMs are in the range of 0.5-3.0 nm. In addition, Thermo-gravimetric Analysis (TGA) was used to investigate chemical kinetics of particulate matter oxidation. The apparent activation energies of oxygenated hydrocarbon, diesel hydrocarbon and carbon oxidation are approximately 91 kJ/mol, 130 kJ/mol and 155 kJ/mol, respectively.

Thermal Effusivity and Thermal Conductivity of Biodiesel/Diesel and Alcohol/Water Mixtures

The photopyroelectric (PPE) technique was used for the determination of the thermal effusivity and thermal conductivity of biodiesel in diesel and other binary liquid mixtures, precisely, ethanol, and ethylene glycol in water. The front configuration (FPPE) has been explored in the frequency scan approach for obtaining thermal-effusivity values. Measurements show good reproducibility, with uncertainties around 1 % to 2 %, and the results for reference samples, such as ethanol and water, are in good agreement with literature values. The thermal-conductivity values of all samples were determined using the thermal-effusivity data presented here and the thermal-diffusivity data of exactly the same set of samples, reported elsewhere. Based on these results, the different strengths in the molecular interactions related to the several mixtures were evidenced, as proposed by Dadarlat et al. It was shown that, indeed, the thermal effusivity is the property presenting the smallest sensitivity for the molecular association phenomenon, while the thermal conductivity presents an intermediate sensitivity. Nevertheless, the analysis of both properties revealed the existence of weak cohesive interactions among the hydrocarbons of diesel and the esters of biodiesel.

Time and cost efficient biodegradation of diesel in a continuous-upflow packed bed biofilm reactor and effect of surfactant GAELE

BACKGROUND: Biodegradation of diesel hydrocarbons using bioreactors has been proposed as an alternative for diesel contaminated sites remediation. To make this alternative feasible, several factors must be optimized or improved: reducing hydraulic retention times (HRT) and applying design methods to enhance the access of the microorganisms to low soluble and recalcitrant compounds like hydrocarbon fuels. In the present work a time and cost efficient continuous-flow packed bed bioreactor at low HRT was designed and evaluated. The effect of non-previously studied anionic surfactant GAELE (glycolic acid ethoxylate lauryl ether) was also investigated. RESULTS: A continuous-upflow packed bed bioreactor (CPR) was built using an inexpensive support made of volcanic and alluvial stones. The biodegradation experiments conducted with a 12-month-old biofilm at a fixed HRT of 0.5 h, recorded removal of up to 97.9% at a diesel concentration of 1120 mg L−1 with GAELE. A first-order rate constant of 0.10 h−1 was calculated. Kinetic analysis using Arvin's model, which introduces mass transfer to the biofilm, showed statistical differences in the kinetic rate parameters (P < 0.001). Moreover, GAELE significantly increased biodegradability at high concentrations, with BOD5 and COD removals up to 90.8 and 80.7%, respectively. Putative hydrocarbon degrading bacteria responsible for the degradation under nitrate-reducing conditions were positively identified. CONCLUSIONS: The continuous-upflow packed bed reactor was capable of high percentage diesel biodegradation at short HRTs. The use of GAELE increased diesel availability and thus enhanced hydrocarbon removal. Therefore, CPR packed with volcanic and alluvial stones combined with GAELE showed potential for the remediation of diesel-impacted sites. Copyright © 2012 Society of Chemical Industry

Application of Light Petroleum Biomarkers for Forensic Characterization and Source Identification of Spilled Light Refined Oils

Light petroleum biomarkers such as bicyclic sesquiterpanes and diamondoids are ubiquitous components of crude oils and ancient sediments, and are also widely found in intermediate petroleum distillates and many finished petroleum products. These compounds are relatively resistant to biodegradation and light-to-medium evaporation weathering, thus particularly useful in oil-source correlation and differentiation for those cases where the traditional tri- to pentacyclic biomarkers are absent. This work utilized sesquiterpanes and diamondoids for fingerprinting and identification of light oils spilled on water. The gas chromatography/flame ionization detection (GC/FID) analysis and distribution profiles of polycyclic aromatic hydrocarbon (PAHs) and conventional biomarkers suggest that the spilled oils are mixtures of mainly gasoline and light diesel type fuel. Since potential source oil candidates were not available, and a large part of the hydrocarbons in gasoline and diesel co-eluted in chromatographic analysis, it is a challenge to quantify the gasoline and diesel in spill samples. It has been known from previous studies that the bulk concentrations of C14 to C16 sesquiterpanes are in the range of approximately 6,000 to 9,000 μg/g for many light diesel fuels, while little or no sesquiterpanes were detected in gasoline, light kerosene and heavy-end lubricating oils. The target sesquiterpanes in the spilled oil samples were determined to be in quite high concentrations: approximately 4,000 μg/g oil. Therefore, it was estimated that these spilled oil samples consist of approximately half gasoline and half light diesel. To verify the estimation, spilled samples were simulated by mixing a fresh gasoline and a light diesel with a similar carbon range as the spilled oils. Results from comparison of GC/FID chromatograms of the spilled oils with the simulated spill samples are consistent with that obtained from sesquiterpane analysis.

Feasibility of Different Bioremediation Strategies for Treatment of Clayey and Silty Soils Recently Polluted with Diesel Hydrocarbons

Bioremediation strategies, including biostimulation, exogenous bioaugmentation and autochthonous bioaugmentation, were evaluated to determine their ability to degrade petroleum hydrocarbons in two recently polluted agricultural soils, one with a clayey texture and a silty loam soil. It was hypothesized in this work that the bioavailability of the pollutant may depend on the soil type, which would determine the biodegradation rate and the correct methodology to be used. The soils were artificially contaminated with diesel fuel, and several soil–water suspension batch microcosm experiments were conducted to observe the bioremediation process. The inocula used in the experiments included an autochthonous soil consortium and an exogenous consortium that had been acclimated to diesel consumption. The clayey soil desorbed diesel quickly, while the silty soil, with a higher organic content, did not. Hydrocarbon availability was limited in the latter case. After 48 h of treatment, the diesel removal efficiency in the clayey soil was clearly higher than that in the silty soil. However, after 11 days, the efficiencies were similar, and more than 95% of the diesel was biodegraded in most experiments. According to the efficiency and bioavailability analyses, the best methodology to bioremediate the silty soil was biostimulation with the native consortium. In contrast, bioaugmentation with a combination of native and exogenous consortia was chosen to treat the clayey soil. The results of this study suggest that when pollutants are easily available, bioaugmentation can successfully remediate the pollution. However, when availability is limited, biostimulation can be more efficient.

Micellar Enhanced Ultrafiltration for the Removal of Polycyclic Aromatic Hydrocarbons (PAHs) Mixtures in Underground Contaminated Water in Oman

In an attempt to analyze polycyclic aromatic hydrocarbons (PAHs) in diesel contaminated underground water in Oman (Rustaq), Gas chromatography-Mass spectrometry was first used to determine the different concentrations in a standard mixture containing 16 PAHs. Retention time and calibration curves were obtained for all aromatic compounds and were used to identify a given analyte as well as its concentration in the contaminated underground water. Micellar enhanced ultrafiltration (MEUF) was then used to treat standard aqueous solution of PAHs at low concentration (~ 1 ppb) using an edible nonionic surfactant (Tween 80). The totality of the mixture components was completely rejected. Within the experimental detection limit (± 0.01 ppb), the residual PAH concentrations were less than 0.01 ppb in accord with the allowed concentrations in drinking water. Likewise, excellent rejections of PAHs in MEUF treatment of diesel contaminated underground water at an Omani site (Rustaq) were observed. The concentration of PAHs was reduced to less than 0.01 ppb, the accepted limit for the most toxic member of the PAH group (benzo(a)pyrene).

Investigating thermal properties of biodiesel/diesel mixtures using photopyroelectric technique

In this work we explored the photopyroelectric technique (PPE) for the thermal characterization of biodiesel/diesel and other binary liquid mixtures, such as ethanol and ethylene glycol in water. We have used the back configuration (BPPE), in the thickness scan approach, and the front one (FPPE), in the frequency scan approach, for getting the thermal diffusivity and effusivity values, respectively. For all the measured systems, we got good data fittings when using the model proposed by Matvienko and Mandelis for thermal diffusivity of liquid mixtures. In addition, we could evidence the different strength in the molecular interaction related to the several mixtures, based on the normalized excess values for thermal diffusivity, as proposed by Dadarlat et al. For biodiesel/diesel mixtures, which present weak cohesive interactions among the saturated/aromatic hydrocarbons of diesel and the alkyl esters of biodiesel, we proposed a semi empirical model for the thermal diffusivity, based on the logarithm mixing model for the thermal conductivity and a simple addictive law for the heat capacity per unit volume.

Strategy for the Supply Chain Development of Biodiesel as an Alternative Fuel in Pakistan

Biodiesel is a clean-burning alternative fuel, produced from domestic, renewable resources. It is biodegradable, nontoxic, and essentially free of sulfur and aromatics. Biodiesel is usually blended with hydro-carbon diesel with ratios 10–90 (called B-10) or 20–80 (called B-20). This bio mix is a tested model in various countries for use as alternative fuel. Biodiesel can be produced from a number of seed oils (used and unused). The production process for resources vary from one to another in terms of minor operational deviations. The flow line from stakeholder to consumer consists of thegrowing of seeds, oil extraction, chemical treatments, and consumption. This flow line involves a number of characters that can play their specific roles behind the scenes. This article proposes a strategy for the development of a supply-chain mechanism for the use of biodiesel as an alternative fuel in Pakistan. The rational of this article is an introduction of biodiesel including its viable sources in Pakistan and its subsequent benefits as principle motivators for the production of biodiesel in Pakistan and the worldwide development in this field. The actual theme of this article is supply-chain development strategy in Pakistan, which covers demand management, identification of inventory requirements, devising the production process flow, deployment models and basic infrastructure requirements. The attributes covered are the availability of raw materials, production processes, handling, transportation, distribution and storage in different stages. In the end, the authors have described expected challenges and uncertainties in deploying the supply chain of biodiesel as an alternate fuel in Pakistan and the possible solutions.

Feasibility of mixed enzymatic complexes to enhanced soil bioremediation processes

This work deals about the feasibility of using different enzymatic complexes to enhance bioremediation of hydrocarbon polluted soils. These complexes were generated by non defined mixed microbial consortia that were isolated from three different oil contaminated sites at an oil refinery, and enriched through weekly aerobic cultivations using diesel hydrocarbons as the sole carbon source. Extracellular proteins mixtures were produced during laboratory batch diesel biodegradation experiments using the three microbial consortia, and after separation from the biomass and remanent substrate, the proteins production and the enzymatic activity were measured in every cases. The trend of the enzymatic activity of these consortia was similar qualitatively, achieving the maximum at the exponential phase of the standard bacterial growth curve; but one of the consortia (C) reached the highest activity (275.316 U/mg). In a second step of this work, batch bioremediation experiments were done to evaluate the feasibility of such enzymatic complexes using the the one that provided the best results (C) to enhance the hydrocarbon removal from a polluted soil carried out by the microbial consortia.

A mathematical model for calculating the increase in the cetane number of diesel fuels in the presence of an ignition initiator

A mathematical model was developed for calculating the increase in the cetane number of diesel fuels in the presence of the ignition initiator 2-ethylhexyl nitrate (EHN) as a function of the initial cetane number of the fuel and the concentration of EHN. The accuracy of the results of the calculations with the model is as good as the accuracy obtained on a bench unit. A mechanism of the reaction of EHN with the hydrocarbons in diesel fuel is proposed based on calculations with the PM6 semiempirical quantum-chemical method.

Renewable Diesel Production from the Hydrotreating of Rapeseed Oil with Pt/Zeolite and NiMo/Al2O3 Catalysts

As an alternative way to produce diesel hydrocarbons, the hydrocracking of rapeseed oil was studied on three different types of bifunctional catalysts: Pt/H-Y, Pt/H-ZSM-5, and sulfided NiMo/γ-Al2O3. Experiments were carried out in a batch reactor over a temperature range of 300−400 °C and initial hydrogen pressures from 5 to 11 MPa. The reaction time was limited to 3 h to prevent a high degree of cracking. The Pt-zeolite catalysts had a strong catalytic activity for both cracking and hydrogenation reactions, and therefore a higher severity was required to reach a relatively high oil conversion into liquid hydrocarbons. With dependence on the activity of the acid sites of the catalysts, the results show a trade-off between the yield of green diesel and the degree of isomerization, which had a direct effect on the cold properties of the diesel. Among the three catalysts, hydrocracking on Ni-Mo/γ-Al2O3 gave the highest yield of liquid hydrocarbons in the boiling range of the diesel fraction, i.e., green dies...

Utilization of Triglycerides and Related Feedstocks for Production of Clean Hydrocarbon Fuels and Petrochemicals: A Review

Catalytic deoxygenation of triglycerides and related feedstocks for production of biofuels is reviewed in this paper. Green diesel, triglyceride-based hydrocarbons in diesel boiling range, is an attractive alternative to biodiesel—a product of transesterification of vegetable oils, particularly due to its superior fuel properties and full compatibility with current diesel fuels. Two basic approaches to production of green diesel—(i) hydrodeoxygenation of triglycerides and related compounds over metal sulfide catalysts and (ii) deoxygenation over supported noble metal catalysts are thoroughly discussed from the point of view of reaction conditions, catalyst composition and reaction pathways and products. Furthermore, catalytic cracking of triglycerides and related feedstocks over microporous and mesoporous catalysts is reviewed as well. It constitutes an interesting alternative to deoxygenation using hydrotreating and noble metal catalysts as it does not consume hydrogen. It provides a wide spectrum of products reaching from olefins to green gasoline and diesel.