Hydrocarbon light

The amount of the individual light hydrocarbons in petroleum (methane to butane or pentane) is often included as part of the preliminary assay. 

Although one of the more conventional distillation procedures might be used, the determination of light hydrocarbons in petroleum is best is carried out with a gas chromatographic method (ASTM D-2427). 

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This method is based on the expression proposed by Lee and Kesler in 1975. It applies mainly to light hydrocarbons. The average error is around 2% when the calculated vapor pressure is greater than 0.1 bar. 

The measurement of the vapor pressure and flash point of crude oils enables the light hydrocarbon content to be estimated. 

During the course of operations such as filling and draining tanks and vessels, light hydrocarbons are lost. These losses are expressed as volume per cent of liquid. According to Nelson (1958), the losses can be evaluated by the equation (/ (/... 

Coefficients for calculation of the enthalpy of an ideal gas (equation 4.77) for common light hydrocarbons. 

Calculational coefficients related to a change of state of common light hydrocarbons. 

If a conventional core has been cut, it will be retrieved from the barrel on the rig floor and crated. It is common to do a lithologic description at this stage. To avoid drying out of core samples and the escape of light hydrocarbons some sections will be immediately sealed in a coating of hot wax and foil. 

Currently, almost all acetic acid produced commercially comes from acetaldehyde oxidation, methanol or methyl acetate carbonylation, or light hydrocarbon Hquid-phase oxidation. Comparatively small amounts are generated by butane Hquid-phase oxidation, direct ethanol oxidation, and synthesis gas. Large amounts of acetic acid are recycled industrially in the production of cellulose acetate, poly(vinyl alcohol), and aspirin and in a broad array of other... 

Typical adsorption isotherms for light hydrocarbons on activated carbon prepared from coconut shells ate shown in Figure 11 (46). The polarizabihties and boiling points of these compounds increase in the order... 

Secunda discharges no process water effluents. AU. water streams produced are cleaned and reused in the plant. The methane and light hydrocarbons in the product are reformed with steam to generate synthesis gas for recycle (14). Even at this large scale, the cost of producing fuels and chemicals by the Fischer-Tropsch process is dominated by the cost of synthesis gas production. Sasol has estimated that gas production accounts for 58% of total production costs (39). 

The inverse emulsion form is made by emulsifying an aqueous monomer solution in a light hydrocarbon oil to form an oil-continuous emulsion stabilized by a surfactant system (21). This is polymerized to form an emulsion of aqueous polymer particle ranging in size from 1.0 to about 10 pm dispersed in oil. By addition of appropriate surfactants, the emulsion is made self-inverting, which means that when it is added to water with agitation, the oil is emulsified and the polymer goes into solution in a few minutes. Alternatively, a surfactant can be added to the water before addition of the inverse polymer emulsion (see Emulsions). 

Table 8. Operational Results of the Hbls Plasma Process in the Cracking of Light Hydrocarbons, ...

The butane-containing streams in petroleum refineries come from a variety of different process units consequently, varying amounts of butanes in mixtures containing other light alkanes and alkenes are obtained. The most common recovery techniques for these streams are lean oil absorption and fractionation. A typical scheme involves feeding the light hydrocarbon stream to an absorber-stripper where methane is separated from the other hydrocarbons. The heavier fraction is then debutanized, depropanized, and de-ethanized by distillation to produce C, C, and C2 streams, respectively. Most often the stream contains butylenes and other unsaturates which must be removed by additional separation techniques if pure butanes are desired. 

Steam Reforming. In steam reforming, light hydrocarbon feeds ranging from natural gas to straight mn naphthas are converted to synthesis gas (H2, CO, CO2) by reaction with steam (qv) over a catalyst in a primary reformer furnace. This process is usually operated at 800—870°C and 2.17—2.86... 

Total Hydrocarbon Gontent. The THC includes the methane combined in air, plus traces of other light hydrocarbons that are present in the atmosphere and escape removal during the production process. In the typical oxygen sample, methane usually constitutes more than 90% of total hydrocarbons. The rest may be ethane, ethylene, acetylene, propane, propylene, and butanes. Any oil aerosol produced in lubricated piston compressor plants is also included here. 

Petroleum Gases and Naphtha. Methane is the main hydrocarbon component of petroleum gases. Lesser amounts of ethane, propane, butane, isobutane, and some 0 + light hydrocarbons also exist. Other gases such as hydrogen, carbon dioxide, hydrogen sulfide, and carbonyl sulfide are also present. 

Asphalt, prepared from petroleum, often resembles native asphalt. When asphalt is produced by distillation, the product is called residual, or straight-mn, asphalt. However, if the asphalt is prepared by solvent extraction of residua or by light hydrocarbon (propane) precipitation, or if it is blown or otherwise treated, the name should be modified accordingly to qualify the product, eg, propane asphalt. 

Vented risers should be provided on most cooling towers to release only light hydrocarbon leakage from the cooling water before the spray header. No ignition or source of spark should be within 30 m of the vented riser. 

Hydrogen produced by the electrolysis of water is used in special circumstances only where electric power is plentiful, inexpensive, and light hydrocarbons are not available. 

Tubular Fixed-Bed Reactors. Bundles of downflow reactor tubes filled with catalyst and surrounded by heat-transfer media are tubular fixed-bed reactors. Such reactors are used most notably in steam reforming and phthaUc anhydride manufacture. Steam reforming is the reaction of light hydrocarbons, preferably natural gas or naphthas, with steam over a nickel-supported catalyst to form synthesis gas, which is primarily and CO with some CO2 and CH. Additional conversion to the primary products can be obtained by iron oxide-catalyzed water gas shift reactions, but these are carried out ia large-diameter, fixed-bed reactors rather than ia small-diameter tubes (65). The physical arrangement of a multitubular steam reformer ia a box-shaped furnace has been described (1). 

Steam Reforming Processes. In the steam reforming process, light hydrocarbon feedstocks (qv), such as natural gas, Hquefied petroleum gas, and naphtha, or in some cases heavier distillate oils are purified of sulfur compounds (see Sulfurremoval and recovery). These then react with steam in the presence of a nickel-containing catalyst to produce a mixture of hydrogen, methane, and carbon oxides. Essentially total decomposition of compounds containing more than one carbon atom per molecule is obtained (see Ammonia Hydrogen Petroleum). 

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