Paraffin branched-chain

The rings most frequently encountered in crude oils are those having five or six carbon atoms. In these rings, each hydrogen atom can be substituted by a paraffinic alkyl chain that is either a straight chain or branched. 

Uses. Fluorosulfuric acid serves as catalyst in the alkylation (qv) of branched-chain paraffins (53—58) and aromatic compounds (59), and in the polymeriza tion of monoolefins (60) and rosin (61). Addition of strong Lewis acids, such as SbF, TaF, and NbF, to fluorosulfuric acid markedly increases... 

Impurities can sometimes be removed by conversion to derivatives under conditions where the major component does not react or reacts much more slowly. For example, normal (straight-chain) paraffins can be freed from unsaturated and branched-chain components by taking advantage of the greater reactivity of the latter with chlorosulfonic acid or bromine. Similarly, the preferential nitration of aromatic hydrocarbons can be used to remove e.g. benzene or toluene from cyclohexane by shaking for several hours with a mixture of concentrated nitric acid (25%), sulfuric acid (58%), and water (17%). 

Naphtha from atmospheric distillation is characterized by an absence of olefinic compounds. Its main constituents are straight and branched-chain paraffins, cycloparaffms (naphthenes), and aromatics, and the ratios of these components are mainly a function of the crude origin. 

Paraffins are straight or branched chain hydrocarbons having the chemical formula C ii2 +2- The name of each member ends with ane examples are propane, isopentane, and normal heptane (Figure 2-1). 

The paraffin hydrocarbon containing four carbon atoms is called butane, but two 4-carbon (C4) paraffins are possible. The butane with its carbons in a line is known as normal butane or n-butane. The branched chain butane is isobutane or i-butane. Although each compound has the formula C4H10, they have different properties for example, n-butane boils at -0.5°C while isobutane boils at -11.7°C. n-Butane and i-butane are isomers of each other. The straight-chain paraffin is always called the normal form. 

J. D. Mercer and L. L. Nesbit. Oil-base drilhng fluid comprising branched chain paraffins such as the dimer of 1-decene. Patent US 5096883,1992. 

Parex (2) [Paraffin extraction] A process for separating linear aliphatic hydrocarbons from branched-chain and cyclic hydrocarbons by means of a zeolite 5 A adsorbent. The products are desorbed with a mixture of steam and ammonia. Developed in the mid-1960s by Luena-Werke and Schwedt in East Germany and operated in East Germany, Bulgaria and the USSR. Broadly similar to Molex and not to be confused with Paiex (1). 

FIGURE 4.2 Structural forms of normal (straight)-chain and branched-chain paraffins. 

Chemical and Physical Properties of Common Normal Paraffin and Branched-Chain Paraffins... 

Paraffins (alkanes single bonds) 1 1 ch4, c2h6, c3h8, c4h10,. c h2 +2 Methane, ethane, propane, butane,..., straight-chain isobutane, branched chain All are saturated (i.e., no more hydrogen can be added to any of the compounds) Radicals deficient in one H atom take the names methyl, ethyl, propyl, etc. 

The shift of curves, as shown in Fig. 3.9, is unsurprising since the larger fuel molecules and their intermediates tend to break down more readily to form radicals that initiate fast reactions. The shape of the propane curve suggests that branched chain mechanisms are possible for hydrocarbons. One can conclude that the character of the propane mechanism is different from that of the H2—02 reaction when one compares this explosion curve with the H2—02 pressure peninsula. The island in the propane-air curve drops and goes slightly to the left for higher-order paraffins for example, for hexane it occurs at 1 atm. For the reaction of propane with pure oxygen, the curve drops to about 0.5 atm. 

Paraffins, saturated hydrocarbons with straight or branched chains but without a ring structure. 

Isomerization the conversion of a normal (straight-chain) paraffin hydrocarbon into an iso (branched-chain) paraffin hydrocarbon having the same atomic composition. 

Aliphatic- Straight- or branch-chain organic molecules that have saturated bonds (paraffins), double bonds (olefins), or triple bonds (acetylenes). 

Hydroforming. The use of hydrogen and pressure and a catalyst to convert an olefinic hydrocarbon to a branch-chain paraffin. 

Pitzer, K.S. and Scott, D.W. Tire thermodynamics of branched-chain paraffins. The heat capacity, heat of fusion and vaporization, and entropy of 2,3,4-trimethylpentane, J. Am. Chem. Soc, 63(9) 2419-2422,1941. 

The alkylation of isoparaffins with olefins is the reaction involved in the large scale processes in the petroleum industry. Any isoparaffin and almost any olefin can be used and although the product in largest percentage is usually with the number of carbon atoms equal to the sum of the carbon atoms in the paraffin and olefin, this is not always the case. A great mixture of branch chain products is obtained (Phillips Petroleum Company, 13). 

Straight chain paraffins autoignite more readily than branched chain paraffins and aromatics of the same carbon number. 

Alkylation A refinery process for producing high-octane components consisting mainly of branched chain paraffins. The process involves combining light olefins with isoparaffins, usually butene and isobutane, in the presence of a strong acid catalyst such as hydrofluoric or sulfuric acid. 

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