Hydrocarbons diesel

Rodgers et al. [85] identified soil surface-bound polycyclic aromatic hydrocarbons through the use of real-time aerosol mass spectrometry in two NIST standard research material soils (Montana SRM 2710 and Peruvian SRM 4355), each contaminated separately with three common petroleum hydrocarbons (diesel fuel, gasoline and kerosene). This method required no sample preparation. Direct laser desorption/ionisation mass spectrometric analysis of individual soil particles contaminated with each of the petroleum hydrocarbons at three different contamination levels (0.8,8, and 80 ppth (wt/wt)) yielded detectable polycyclic aromatic hydrocarbon cation distributions that ranged from m/z 128 to 234, depending on the fuel contaminant. The same analysis... 

A fingerprint can be used to conclusively identify a mixture when a known sample of that mixture is available as a reference material. As most GC-based methods cover specific ranges, it is more appropriate to quote TPH measurement by range i.e. TPHD (total petroleum hydrocarbons diesel) . 

Reactors for Low-Temperature Operation The preceding discussion in Section 3.3.1b shows that the low-temperature mode is used for obtaining higher carbon number hydrocarbons (diesel/waxes). Sasol started this mode with five shell- and tube-type fixed beds in 1955. These reactors operated at 2.7 MPa and 230 °C, producing 21,0(X)... 

Fuel oil, bp 250 to 400 °C, is a mixture of C15 to Cjs hydrocarbons. Diesel fuel is obtained from this fraction. 

Universal across-the-board cleanup criteria are not commonly used as end points for soil and groundwater cleanup, because of the wide range of risks found at these sites. However, two classes of contaminants have been subject to universal action levels for cleanup petroleum and polychlorinated biphenyls (PCBs). Most petroleum hydrocarbon action levels are regulated by state and local agencies the parameters used and their corresponding action levels vary widely from state to state. The specific petroleum parameters that are regulated include total petroleum hydrocarbon— gasoline fraction (TPH-G) total petroleum hydrocarbon—diesel component (TPH-D) ... 

The process has been applied to kerosene to improve the smoke point and for desulfurization. It is applied to selected naphthas for the recovery of high-octane-number blending stocks and for the recovery of lacquer diluents (aromatic hydrocarbons). Diesel fuels of high Diesel Index and ignition quality can be made from selected gas oils. 

In a general manner, diesel engines, jet engines, and domestic or industrial burners operate with lean mixtures and their performance is relatively insensitive to the equivalence ratio. On the other hand, gasoline engines require a fuel-air ratio close to the stoichiometric. Indeed, a too-rich mixture leads to an excessive exhaust pollution from CO emissions and unburned hydrocarbons whereas a too-lean mixture produces unstable combustion (reduced driveability and misfiring). 

The behavior of the diesel fuel is compared to that of two pure hydrocarbons selected as a reference J... 

The density of heavy fuels is greater than 0.920 kg/1 at 15°C. The marine diesel consumers focus close attention on the fuel density because of having to centrifuge water out of the fuel. Beyond 0.991 kg/1, the density difference between the two phases —aqueous and hydrocarbon— becomes too small for correct operation of conventional centrifuges technical improvements are possible but costly. In extreme cases of fuels being too heavy, it is possible to rely on water-fuel emulsions, which can have some advantages of better atomization in the injection nozzle and a reduction of pollutant emissions such as smoke and nitrogen oxides. 

The crankcase of a gasoline or diesel engine is in reality a hydrocarbon oxidation reactor oil is submitted to strong agitation in the presence of air at high temperature (120°C) furthermore, metals such as copper and iron, excellent catalysts for oxidation, are present in the surroundings. 

Additional research for both ethanol and methanol showed that the amount of ignition improver could be reduced by systems increa sing engine compression (63). Going from 17 1 to 21 1 reduced the amount of TEGDN requited for methanol from 5% by volume to 3%. Ignition-improved methanol exhibited very low exhaust emissions compared to diesels particulate emissions were eliminated except for small amounts associated with engine oil, NO was even lower with increased compression, and CO and hydrocarbons were also below diesel levels. 

Methanol use would also reduce pubHc exposure to toxic hydrocarbons associated with gasoline and diesel fuel, including ben2ene, 1,3-butadiene, diesel particulates, and polynuclear aromatic hydrocarbons. Although pubHc formaldehyde exposures might increase from methanol use in garages and tunnels, methanol use is expected to reduce overall pubHc exposure to toxic air contaminants. 

Direct hydrohquefaction of biomass or wastes can be achieved by direct hydrogenation of wood chips on treatment at 10,132 kPa and 340 to 350°C with water and Raney nickel catalyst (45). The wood is completely converted to an oily Hquid, methane, and other hydrocarbon gases. Batch reaction times of 4 hours give oil yields of about 35 wt % of the feed the oil contains about 12 wt % oxygen and has a heating value of about 37.2 MJ /kg (16,000 Btu/lb). Distillation yields a significant fraction that boils in the same range as diesel fuel and is completely miscible with it. 

Methanol is more soluble in aromatic than paraffinic hydrocarbons. Thus varying gasoline compositions can affect fuel blends. At room temperature, the solubiUty of methanol in gasoline is very limited in the presence of water. Generally, cosolvents are added to methanol—gasoline blends to enhance water tolerance. Methanol is practically insoluble in diesel fuel. 

The cetane number of a fuel depends on its hydrocarbon composition. In general, normal paraffins have high cetane numbers, isoparaffins and aromatics have low cetane numbers, and olefins and cycloparaffins fall somewhere in between. Diesel fuels marketed in the United States have cetane numbers ranging between 35 and 65. Most manufacturers specify a minimum cetane number of 40—45. 

The functional group ia collectors for nonsulfide minerals is characterized by the presence of either a N (amines) or an O (carboxyUc acids, sulfonates, etc) as the donor atoms. In addition to these, straight hydrocarbons, such as fuel oil, diesel, kerosene, etc, are also used extensively either as auxiUary or secondary collectors, or as primary collectors for coal and molybdenite flotation. The chain length of the hydrocarbon group is generally short (2—8 C) for the sulfide collectors, and long (10—20 C) for nonsulfide collectors, because sulfides are generally more hydrophobic than most nonsulfide minerals (10). 

In shape-selective catalysis, the pore size of the zeoHte is important. For example, the ZSM-5 framework contains 10-membered rings with 0.6-nm pore size. This material is used in xylene isomerization, ethylbenzene synthesis, dewaxing of lubricatius oils and light fuel oil, ie, diesel and jet fuel, and the conversion of methanol to Hquid hydrocarbon fuels (21). 

The term naphthenic acid, as commonly used in the petroleum industry, refers collectively to all of the carboxyUc acids present in cmde oil. Naphthenic acids [1338-24-5] are classified as monobasic carboxyUc acids of the general formula RCOOH, where R represents the naphthene moiety consisting of cyclopentane and cyclohexane derivatives. Naphthenic acids are composed predorninandy of aLkyl-substituted cycloaUphatic carboxyUc acids, with smaller amounts of acycHc aUphatic (paraffinic or fatty) acids. Aromatic, olefinic, hydroxy, and dibasic acids are considered to be minor components. Commercial naphthenic acids also contain varying amounts of unsaponifiable hydrocarbons, phenoHc compounds, sulfur compounds, and water. The complex mixture of acids is derived from straight-mn distillates of petroleum, mosdy from kerosene and diesel fractions (see Petroleum). 

To overcome these difficulties, drilling fluids are treated with a variety of mud lubricants available from various suppHers. They are mostly general-purpose, low toxicity, nonfluorescent types that are blends of several anionic or nonionic surfactants and products such as glycols and glycerols, fatty acid esters, synthetic hydrocarbons, and vegetable oil derivatives. Extreme pressure lubricants containing sulfurized or sulfonated derivatives of natural fatty acid products or petroleum-base hydrocarbons can be quite toxic to marine life and are rarely used for environmental reasons. Diesel and mineral oils were once used as lubricants at levels of 3 to 10 vol % but this practice has been curtailed significantly for environmental reasons. 

In general, when the product is a fraction from cmde oil that includes a large number of individual hydrocarbons, the fraction is classified as a refined product. Examples of refined products are gasoline, diesel fuel, heating oils, lubricants, waxes, asphalt, and coke. In contrast, when the product is limited to, perhaps, one or two specific hydrocarbons of high purity, the fraction is classified as a petrochemical product. Examples of petrochemicals are ethylene (qv), propylene (qv), benzene (qv), toluene, and xylene (see Btx processing). 

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