000 02584nab a2200205 4500
005 20260520000818.0
008 260224s2009 xxu
245 0 0 _aBranching structure of diesel and lubricant base oils prepared by isomerization/hydrocracking of fischer - tropsch waxes and a-olefins
260 _a
_b
_cene. 2009
270 _a15/05/2009 ; 22/04/2009
300 _a5 p. ; 513-518
520 _aTranscripción del resúmen publicado por el autor: Lubricant base oils were prepared from two Fischer-Tropsch (FT) waxes and two a-olefins with different carbon number distributions under several isomerization/hydrocracking conditions. The molecular structures of the resulting oils were investigated using 13C NMR analysis to determine the location and length of branches. Peak areas assigned to the CH carbons were divided into eight groups and correlated with the progress of the isomerization reaction. Each group showed good correlation with the density of branching, which was expressed as the ratio of the average branching number (ABN) to the average carbon number (ACN). This trend was independent of the feedstock used and the reaction conditions. The probability of methyl branching at a carbon atom depended on its location from the terminal carbon; that is, in order of decreasing probability, the carbon location is second > third > fourth, and so forth, and the probability of the seventh and eighth or inner carbon atoms was almost equal. A trend of increasing proportion of branches located at the second carbon was observed. Diesel oils were also obtained by isomerization/hydrocracking of FT waxes, and the most likely position of methyl branching was the second carbon from the terminal carbon. Branching at the second carbon showed a decreasing trend with increasing density of branching in diesel oil, whereas that in lubricant base oil showed an increasing trend. The present work demonstrated that the position and length of the branches in lubricant base oils, and diesel oils prepared by isomerization/hydrocracking of FT waxes and a-olefins, are determined by the density of branching, thus supporting previous findings that viscosity properties of lubricant oils, such as the kinematic viscosity and viscosity index, can be expressed using only the ACN and ABN.
773 0 _tEnergy & fuels
_g23
942 _cARTICULO
100 1 _aKobayashi, Manabu
_941011
100 1 _aSaitoh, Masayuki
_941012
100 1 _aTogawa, Seiji
_941013
999 _c169648
_d169648
856 _uhttp://pubs.acs.org/doi/full/10.1021/ef800530p