Diesel Range Hydrocarbons Research Articles

Hydrotreating and hydrocracking catalysts for processing of waste soya-oil and refinery-oil mixtures

Abstract Mesoporous SiO2–Al2O3 and Al2O3 were used as supports to prepare hydrocracking (sulfided Ni–W/SiO2–Al2O3) and hydrotreating (sulfided Ni–Mo/Al2O3) catalysts. These hydroprocessing catalysts were used under typical hydroprocessing conditions to convert waste soya-oil mixtures with refinery-oil into saturated hydrocarbons. The hydrocracking catalyst was more selective for the kerosene range (140–250 °C) hydrocarbons while the less acidic hydrotreating catalyst was more selective for the diesel range (250–380 °C) hydrocarbons. The hydrodeoxygenation pathway for oxygen removal from triglycerides seems to be favored over the hydrotreating catalyst, while decarboxylation + decarbonylation pathway is favored over the hydrocracking catalyst.

Catalytic upgrading of oil fractions separated from food waste leachate

In this work, catalytic cracking of biomass waste oil fractions separated from food waste leachate was performed using microporous catalysts, such as HY, HZSM-5 and mesoporous Al-MCM-48. The experiments were carried out using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to allow the direct analysis of the pyrolytic products. Most acidic components, especially oleic acid, contained in the food waste oil fractions were converted to valuable products, such as oxygenates, hydrocarbons and aromatics. High yields of hydrocarbons within the gasoline-range were obtained when microporous catalysts were used; whereas, the use of Al-MCM-48, which exhibits relatively weak acidity, resulted in high yields of oxygenated and diesel-range hydrocarbons. The HZSM-5 catalyst produced a higher amount of valuable mono aromatics due to its strong acidity and shape selectivity. Especially, the addition of gallium (Ga) to HZSM-5 significantly increased the aromatics content.

Processing of Triglycerides to Diesel Range Hydrocarbon Fuels: Easily Practicable Small Scale Approach

Lipid fraction of biomass has been identified as carbon neutral substitution to fuels from fossil sources in the transportation sector. Although, the diesel engine, invented by Rudolph Diesel over a century ago first ran on peanut oil, the current combustion engines are designed to run on hydrocarbon fuels derived from petroleum. Therefore, a substitute for diesel fuel from renewable source will need to have identical or closely similar properties. The most popular of the existing technology for processing vegetable or animal oils is based on the conversion of the triglycerides constituents to fatty acids methyl esters (FAME). FAME technology does not produce diesel fuel with identical properties as petro-diesel. Other alternative processing routes are dilution of the vegetable oils, emulsification, pyrolysis and hydrotreating. These routes are discussed in this paper. Appropriate technologies for small scale production of diesel range hydrocarbon fuel from vegetable oil without the need for co-reactants such methanol or hydrogen as part of the feedstock is emphased. Also alternative catalyst systems in place of the expensive precious metal supported catalysts are suggested.

Wet deposition of hydrocarbons in the city of Tehran-Iran

Air pollution in the city of Tehran has been a major problem for the past three decades. The direct effects of hydrocarbon contaminants in the air are particularly important such as their carcinogenic, mutagenic, and teratogenic effects which can be transported to other environments via dry and wet deposition. In the present study, rainwater samples were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, ethyl benzene, and xylene (BTEX) as well as fuel fingerprints in two ranges of gasoline (C5–C11) and diesel fuel (C12–C20) using a gas chromatograph equipped with a flame ionization detector (GC/FID). Mean concentrations of ∑16 PAHs varied between 372 and 527 µg/L and for BTEX was between 87 and 188 µg/L with maximum of 36 µg/L for toluene. Both gasoline range hydrocarbons (GRH) and diesel range hydrocarbons (DRH) were also present in the collected rainwater at concentrations of 190 and 950 µg/L, respectively. Hydrocarbon transports from air to soil were determined in this wet deposition. Average hydrocarbon transportation for ∑PAHs, BTEX, GRH, and DRH was 2,747, 627, 1,152, and 5,733 µg/m2, respectively.

Mass- and heat-transfer-enhanced catalyst system for Fischer-Tropsch synthesis in fixed-bed reactors

Fischer-Tropsch synthesis (FTS) was carried out using Al2O3-supported Co catalyst coated on metallic monolith. Considering the liberation of a large amont of heat from the highly exothermic FTS reaction, catalytic activity of Co catalyst coated on metallic monolith was tested and compared with that of pellet-type catalysts. The reaction was carried out in a conventional tubular fixed-bed reactor and simulated distillation (SIMDIS) analysis method was used to determine the liquid products distribution. Proper control of degree of reaction, as well as the reaction temperature gave rise to a shift of products selectivity toward higher hydrocarbons, especially C13−C18 diesel range hydrocarbons.

Forensic Environmental Geochemistry in Dispute Resolution—Case History 2: Differentiating Sources of Diesel Fuel in a Plume at a Fueling Station

Shortly after completion of remedial activities, a subsurface plume of non-aqueous-phase liquid was discovered at a truck fueling facility located in Columbia, New Jersey. Seven samples, collected at the site during three separate sampling events, were analyzed for diesel range saturated hydrocarbons and polycyclic aromatic hydrocarbons. The results indicated that the samples were composed of diesel fuel under various degrees of weathering in the subsurface environment. Distribution patterns of diesel-range alkane and aromatic hydrocarbons, combined with evaluation of source and weathering diagnostic ratios, provided sufficient information to differentiate two separate sources of diesel fuel contamination. It was concluded that diesel fuel releases occurred both before and after the sale of the property in March 2000.

Hydrocracking of Fischer–Tropsch Wax to Diesel-range Hydrocarbons over Bifunctional Catalysts Containing Pt and Polyoxocation-pillared Montmorillonite

Abstract Bifunctional catalysts containing Pt and polyoxocation-pillared montmorillonite showed high yields of diesel-range hydrocarbons (>70%) in the hydrocracking of Fischer–Tropsch wax due to their weak acid strength, high thermal stability, large surface area, and large pore size.

Distribution of Petroleum and Aromatic Hydrocarbons at a Former Crude Oil and Natural Gas Production Facility

Site characterization and remediation activities were performed at a former crude oil and natural gas production facility prior to redevelopment of the site. Field activities included delineation, excavation and segregation of approximately 1,250,000 m3 of soil impacted by total petroleum hydrocarbons (TPH) and the aromatic volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and xylenes (hereafter, collectively referred to as BTEX). Petroleum hydrocarbon chain length information was used to determine whether remediation was required in impacted areas, because the site-specific cleanup values for TPH compounds, established by the California State Regional Water Quality Control Board (RWQCB), were based on hydrocarbon chain length. Site-specific cleanup levels were also established by the RWQCB for BTEX. Subsurface investigation activities performed at the site indicated that the mean percentage of condensate and TPH compounds in the gasoline range was significantly greater at depths ranging from 4.6 to 18 m than in shallower samples. There was no significant difference in the mean concentration of BTEX compounds and mean percentage of diesel range and heavier hydrocarbons with depth. The occurrence of BTEX, diesel range, and heavier hydrocarbons at depth may result from preferential pathways for downward migration of contaminants, including blown out wells, abandoned wellbores, and the presence of faults. Vapor phase diffusion may also be a major transport mechanism controlling movement of BTEX compounds beneath the site.

Cracking of a rapeseed vegetable oil under realistic FCC conditions

A rapeseed vegetable oil, pure and blended with conventional FCC feedstock, has been catalytically cracked with a commercial equilibrium catalyst under realistic FCC conditions. The rapeseed oil can be converted into gasoline- and diesel-range hydrocarbons that are low in sulfur and nitrogen. The triglycerides are predominately converted within 50ms at 485–585°C into fatty acids through radical cracking reactions. Relatively high amounts of coke are formed. The high aromatisation rate of the fatty acids causes the formation of large amounts of aromatics of up to 30–40wt.% in the gasoline fraction. Due to the high aromaticity the product is hardly subject to serial cracking reactions and the lower olefins yield (C3 and C4) remains low. The rate of aromatisation is highly dependent on the olefinicity of the fatty acid and the reaction temperature. The catalytic conversion of the carbon–carbon bond saturated stearic acid results in a higher gasoline yield (57wt.% versus 34wt.% for the rapeseed oil) with a much lower aromaticity (13wt.% in gasoline versus 32wt.% in gasoline for the rapeseed oil). Due to the lower aromaticity the serial cracking reactions to the lower olefins are much better (7wt.% C3 and 7wt.% C4). In all cases, the oxygen from the fatty acids is evolved predominantly as water. Other oxygenates have not been observed in significant quantities.

Using Comprehensive Two-Dimensional Gas Chromatography Retention Indices To Estimate Environmental Partitioning Properties for a Complete Set of Diesel Fuel Hydrocarbons

Comprehensive two-dimensional gas chromatography (GCxGC) provides nearly complete composition data for some complex mixtures such as petroleum hydrocarbons. However, the potential wealth of physical property information contained in the corresponding two-dimensional chromatograms is largely untapped. We developed a simple but robust method to estimate GCxGC retention indices for diesel-range hydrocarbons. By exploiting n-alkanes as reference solutes in both dimensions, calculated retention indices were insensitive to uncertainty in the enthalpy of gas-stationary-phase transfer for a suite of representative diesel components. We used the resulting two-dimensional retention indices to estimate the liquid vapor pressures, aqueous solubilities, air-water partition coefficients, octanol-water partition coefficients, and vaporization enthalpies of a nearly complete set of diesel fuel hydrocarbons. Partitioning properties were typically estimated within a factor of 2; this is not as accurate as some previous estimation or measurement methods. However, these relationships may allow powerful and incisive analysis of phase-transfer processes affecting petroleum hydrocarbon mixtures in the environment. For example, GCxGC retention data might be used to quantitatively deconvolve the effects of water washing and evaporation on environmentally released diesel fuels.

Silica Xerogel Supported Cobalt Metal Fischer−Tropsch Catalysts for Syngas to Diesel Range Fuel Conversion

Fischer−Tropsch synthesis of diesel range straight-chain hydrocarbons from CO and H2 over a cobalt nanoparticle catalyst supported by a mesoporous silica xerogel is reported. A possible advantage of sol−gel-derived catalyst supports is the tunability of their porosity to favor synthesis of diesel range hydrocarbons. The preparation of the xerogel supports, optimal loading of the supports with cobalt, the percent conversion of syngas to Fischer−Tropsch hydrocarbons, a gas chromatography−mass spectrometry analysis of the diesel range product distribution, and characterization of the catalysts are reported.

00/02365 Development of Fe Fischer—Tropsch catalysts for slurry bubble column reactors

Alternative reactor configurations and the utilization of a low-alpha versus high-alpha iron-based catalyst are compared for the Fischer-Tropsch synthesis based on actual catalyst performance. The use of coal-derived synthesis gas with a low H2/CO ratio requires a judicious balance between the rates of the Fischer-Tropsch and water-gas shift reactions. The hydrocarbon space-time yield is considerably increased by using either a reactor with recycle or a series of reactors with low syngas conversion per pass instead of a single-pass reactor with high syngas conversion. The production of gasoline and diesel-range hydrocarbons by downstream processing of the Fischer-Tropsch reaction products involves both hydrocracking and oligomerization. The difference between processing the products from a low-alpha and a high-alpha iron-based catalyst lies merely in the relative sizes of the hydrocracking and oligomerization reactors required. In addition, it is advantageous to use a low-alpha catalyst from the viewpoint of Fischer-Tropsch slurry reactor operation.

Fischer-Tropsch synthesis: Process considerations based on performance of iron-based catalysts

Alternative reactor configurations and the utilization of a low-alpha versus high-alpha iron-based catalyst are compared for the Fischer-Tropsch synthesis based on actual catalyst performance. The use of coal-derived synthesis gas with a low H 2/CO ratio requires a judicious balance between the rates of the Fischer-Tropsch and water-gas shift reactions. The hydrocarbon space-time yield is considerably increased by using either a reactor with recycle or a series of reactors with low syngas conversion per pass instead of a single-pass reactor with high syngas conversion. The production of gasoline and diesel-range hydrocarbons by downstream processing of the Fischer-Tropsch reaction products involves both hydrocracking and oligomerization. The difference between processing the products from a low-alpha and a high-alpha iron-based catalyst lies merely in the relative sizes of the hydrocracking and oligomerization reactors required. In addition, it is advantageous to use a low-alpha catalyst from the viewpoint of Fischer-Tropsch slurry reactor operation.

Optimization of the Microwave-Assisted Solvent Extraction of Petroleum Hydrocarbons in Marine Sediment and Soil

A microwave-assisted solvent extraction (MASE) technique was developed for the quantitative extraction of gasoline- and diesel-range petroleum hydrocarbons (PHs) from soil and marine sediment samples. The influence of different extracting solvents, extraction temperature and duration of extraction on the recoveries of PHs was evaluated using a two-level orthogonal array design (OAD) with a OA8(27) matrix. Gas chromatographic-mass spectrometry (GC-MS) in multiple selective ion monitoring (MSIM) mode was used for the analysis of the PHs in environmental samples. The spiking range of the PHs in the environmental samples was between 1 to 1000 μg/g. Good recoveries (>80%) could be obtained for most of the PHs using the optimum MASE conditions. The limit of detection (LOD) achieved by the GC-MS-MSIM was 0.02 μg/g. A preliminary survey for the levels of PHs in marine sediment and soil samples from different parts of Singapore was carried out using the method.

Determination of Diesel Fuel and Motor Oil in Water and Wastes by a Modified Diesel-Range Organics Total Petroleum Hydrocarbon Method

Abstract The American Petroleum Institute method for determination of diesel-range total petroleum hydrocarbon (TPH) by gas-liquid chromatography with flame ionization detection was modified to allow simultaneous determination of motor oil. Motor oil elutes as a broad hump of unresolved alkanes and can be distinguished readily from diesel fuel and other fuel oils by its profile. The boiling point ranges for No. 2 diesel fuel and motor oil are C10– C21 and C21–C38, respectively, and these ranges define TPHs in diesel fuel (TPH-D) and motor oil (TPH- M). By this convention, less than 6% of No. 2 diesel is characterized as TPH-M, and less than 9% of motor oil is quantitated as TPH-D. Inlet discrimination was observed when motor oil was injected with a splitless injector. Accurate motor oil quantitation with splitless sample introduction requires calibration with the product or triacontane, which has a similar response factor. Detector response to motor oil (and other petroleum products) and a homologous series of n-alkanes was nearly constant when on-column injection was used. Instrument detection limit for motor oil was about 0.5 μg (split- less injection, total area under the curve), and the widest linear range (up to 100 μg) was obtained by subtracting the solvent chromatogram. Procedures for isolation of motor oil from oil-in-water (O/W) and water-in-oil (W/0) emulsions are described. Method detection limits for diesel fuel and motor oil in purified water were 0.041 and 1.5 mg/L, respectively.

Comparison of sorbent and solvent trapping after supercritical fluid extraction of volatile petroleum hydrocarbons from soil

Abstract Supercritical fluid extraction (SFE) with sorbent and solvent traps was used for extracting total petroleum hydrocarbons (TPH) from real-world soil samples contaminated with gasoline- or diesel-range hydrocarbons. Quantitative extractions using two SFE systems were performed at 80°C and 340 atm with a flow-rate of 1.5 ml/min. Both sorbent and solvent trapping could effectively (⩾90%) collect BTEX (benzene, toluene, ethylbenzene, and xylenes). Sorbent trapping yielded quantitative collections (⩾88%) of n -alkanes as volatile as n -hexane, while the solvent trapping effectively collected n -alkanes as volatile as n -heptane (pressurized trapping system) or n -octane (normal trapping system). The quantitation of BTEX, TPH, and individual species from contaminated soils obtained by the two SFE systems agreed well. Because of the greater losses of BTEX and volatile n -alkanes, Soxhlet extraction yielded significantly lower BTEX, TPH, and individual species values than SFE.

Arctic Bioremediation—A Case Study

Summary This paper discusses the use of bioremediation as an effective method to clean up diesel-range hydrocarbon spills in northern latitudes. The results of a laboratory study of microbial degradation of hydrocarbons under simulated arctic conditions showed that bioremediation can be effective in cold climates and led to the implementation of a large-scale field program. The results of 3 years of field testing have led to a significant reduction in diesel-range hydrocarbon concentrations in the contaminated area.

Synthesis of liquid fuels from products of biomass gasification

Liquid hydrocarbons can be successfully produced from the product of air-biomass gasification by Fischer-Tropsch synthesis over cobalt catalysts. The presence of considerable concentrations of carbon dioxide and nitrogen in the reaction feed influences this process: carbon dioxide by reducing the probability of side reactions, and nitrogen by promoting the formation of diesel range hydrocarbons.

Impact of diseases on livestock production in the tropics

Hydrodeoxygenation (HDO) of vegetable oil is one of the promising key processes designed for a possible convenient method for automotive clean fuel production. The HDO of rubber seed oil into diesel range hydrocarbon over non-sulphided monometallic (Ni/γ-Al2O3 and Mo/γ-Al2O3) catalysts were investigated. The catalysts were synthesized via conventional wet impregnation method using 3 wt.%, 12 wt.% and 15 wt.% Ni and Mo loading over γ-Al2O3 support, to examine the influence of metal loading on catalytic activity, coke deposition, and reaction routes. The synthesized catalysts were subjected to characterization techniques including XRD, FESEM coupled with EDX, BET, TEM, TGA, ICP-OES and H2TPR. All the catalysts were tested for HDO reaction at 623.15 K, 3.5 MPa, H2/oil of 1000 N (cm3/cm3) with WHSV = 1 h−1 in a continuous flow fixed bed tubular reactor. The hydrocarbon products were analyzed using gas chromatography, and intermediates were identified using GC–MS.The Ni supported catalysts showed comparatively higher surface area, small particle size, homogeneous dispersion of particles, higher crystallinity and lower reduction temperature, low coke deposition. Proposed reaction mechanism suggests the decarboxylation (DCO2) reaction occurred mainly over Ni supported catalysts. Whereas, higher Ni loading reduced the extent of decarboxylation (DCO2) reaction. Additionally, Mo supported catalysts allowed the deoxygenation reaction to occur and higher Mo loading enhanced the extent of hydrodeoxygenation (HDO). The triglycerides conversion for all the catalysts was 99.9%. The catalysts with higher metal loading showed overall higher catalytic activity for hydrodeoxygenation of RSO. 15 wt.% Ni loading produced higher hydrocarbon yield (55.1 wt.%) whereas, 15 wt.% Mo loading produced up to 61.7 wt.%. Mo comparatively produced high amount of C16 (15.7 wt.%), and C18 (30.7 wt.%) hydrocarbons. Whereas, Ni produced mainly C15 (20.9 wt.%) and C17 (20.3 wt.%) hydrocarbons. Significant findings were observed on hydrocarbon yield, intermediates, and amount of coke formation. Mo supported catalysts shows significant HDO activity with less concentration of oxygenated component in the mixture. Besides Mo supported catalysts exhibit the high amount of coke deposition compared to Ni supported catalysts.