of representative diesel fuel hydrocarbons
Boiling Points
For compounds in the same class, boiling point increases with carbon number. Forcompounds of the same carbon number, the order of increasing boiling point by class is isoparaffin, n-paraffin, naphthene, and aromatic. The boiling point difference (60 В° to80 В° C or 100 В° to 150 В° F) between isoparaffins and aromatics of the same carbon number is larger than the boiling point difference (about 20 В° C or 35 В° F) between compounds of the same class that differ by one carbon number. Thus, the compounds that boil at about 260 В° C (500 В° F), the middle of the diesel fuel boiling range, might be C12 aromatics, C13 naphthenes, C14 n-paraffin, and C15 isoparaffins. p align="justify"> Freezing Point
Freezing points (melting points) also increase with molecular weight, but they are strongly influenced by molecular shape. Molecules that fit more easily into a crystal structure have higher freezing points than other molecules. This explains the high melting points of n-paraffins and unsubstituted aromatics, compared to the melting points of isoparaffins and naphthenes of the same carbon number. br/>
Compound Chemical Hydrocarbon Boiling Freezing Formula Class Point, В° C/ В° F Point, ЦC/ В° F
Naphthalene C10H8 Aromatic 218/424 80/176 Tetralin C10H12 Aromatic 208/406 -35/-31 cis-Decalin C10H18 Naphthene 196/385 -43/-45 1,3-Diethylbenzene C10H14 Aromatic 181/ 358 -84/-119 n-Butylcyclohexane C10H20 Naphthene 181/358 -75/-103 n-Pentylcyclopentane C10H20 Naphthene 181/358 -83/-117 Decane C10H22 n-Paraffin 174/345 -30/-22 Anthracene C14H10 Aromatic 341/ 646 215/419 1-Pentylnaphthalene C15H18 Aromatic 306/583 -24/-11 n-Nonylcyclohexane C15H30 Naphthene 282/540 -10/14 n-Decylcyclopentane C15H30 Naphthene 279/534 -22/-8 n-Pentadecane C15H32 n-Paraffin 271 /520 10/50 2-Methyltetradecane C15H32 Isoparaffin 265/509 -8/18 1-Decylnaphthalene C20H28 Aromatic 379/714 15/59 n-Tetradecylbenzene C20H34 Aromatic 354/669 16/61 n-Tetradecylcyclohexane C20H40 Naphthene 354/669 25/77 n-Pentadecylcyclopentane C20H40 Naphthene 353/667 17/63 Eicosane C20H42 n-Paraffin 344/651 36/97 2-Methylnonadecane C20H42 Isoparaffin 339/642 18/64
Density
Table lists density and heat of combustion (heating value) for some representative diesel fuel hydrocarbons. For compounds of the same class, density increases with carbon number. For compounds with the same carbon number, the order of increasing density is paraffin, naphthene, and aromatic. br/>
Net Heat of Net Heat of Hydrocarbon Carbon Density, Combustion, Combustion, Compound Class N...
