FIELD: chemistry.
SUBSTANCE: invention relates to method of isomerisation of initial raw material, containing paraffins, which have 5 and 6 carbon atoms, in which, at least, 15 wt% of initial raw material represent linear paraffins, in order to obtain izomerization product, which contains isomerised paraffins, including: a) initial raw material isomerisation in isomerisation conditions including reactor temperature from 40° to 250°C and working absolute pressure from 100 kPa to 10 MPa in presence of isomerization catalyst, in order to obtain isomerization product containing linear paraffins but in concentration lower than in initial raw materal; b) distillation of, at least, part of isomerisation product, in order to obtain low-boiling fraction, containing dimethylbutanes and light paraffins, and high-boiling fraction, containing normal hexane, methylpentanes, dimethylbutanes and methylcyclopentane; c) contacting of, at least, part of fraction containing normal hexane from stage b), with inlet side of selectively permeable membrane in conditions including sufficient area of membrane surface and pressure difference on membrane in order to obtain retainable fraction, in which there is higher concentration of methylcyclopentane and dimethylbutanes, and obtain on outlet side of membrane diffused fraction, which has higher concentration of normal hexane and methyl pentanes, said diffused fraction containing, at least, 75 wt % of normal hexane, contained in fraction including normal hexane and contacting with membrane; and d) removal of retained product from stage c). Claimed invention also relates to device for realisation of claimed method.
EFFECT: application of claimed method allows to obtain isomerisation product possessing higher octane number.
15 cl, 1 dwg
