Production of Heavy Aromatic Hydrocarbons by Catalytic Reforming (Part 3)

Abstract

Studies were carried out to investigate the composition of C6-C10 alkylbenzenes and C10-C12 alkylnaphthalenes in reformate and the yield of aromatics which were obtained by catalytic reforming of kerosene, using the commercial platinum-alumina reforming catalyst.1) Kerosene fractions having the boiling range of 210∼220°C, 220∼230°C, 230∼240°C, 240∼250°C and 250∼260°C obtained from Gach Saran crude oil were reformed.Kerosenes having boiling ranges of 210∼220°C, 230∼240°C and 250∼260°C gave higher yields (crude oil basis) of aromatics. Naphthalenes contents in reformates increased with raising of boiling point of the feed. However, compositions of C8, C9 and C10 aromatic isomers remained unchanged regardless of the boiling range of kerosene fractions.2) Gach Saran kerosene (180∼250°C) was reformed using the operating conditions as follows; the temperature 450∼530°C, the pressure 10∼50atm, the liquid hourly space velocity 0.6-8.4 and the mole ratio of hydrogen to hydrocarbon 5-15. From the data obtained, the relationship between the operating conditions and the yield, compositions of aromatics in reformates were investigated.3) Kerosenes of Gach Saran, North Sumatra, and Ekhabinskaya, having the boiling range of 180∼250°C and C10-C12 n-paraffins were reformed.The yields of reformates and the aromatics in reformates obtained from kerosenes varied with the kind of feed, but the compositions of aromatic isomers did not change with the feed.The yields of aromatics in reformates obtained from C10, C11 and C12 n-paraffins showed almost the same values, and compositions of aromatic isomers agreed with each other. Generally, C8-C10 aromatic isomers in the reformates obtained from C10-C12 n-paraffins contained more poly-methylbenzenes, and less mono-alkylbenzenes and alkylindanes than those obtained from kerosenes. From the above results, main pathway of dehydrocyclization of C10-C12 n-paraffins using the acidic platinum-alumina catalyst seems to be formed through iso-paraffin.