Abstract: Hydroisomerization of paraffinic base diesel fraction over a hydroisomerization catalyst was conducted in a fixed-bed reactor of pilot plant under different conditions. Results indicated that within a certain temperature range the hydroisomerization reaction and hydrocracking reaction are increased with increasing reaction temperature. While the hydroisomerization reaction and hydrocracking reaction is suppressed as the reaction pressure or space velocity increases. Although the hydroisomerization activity decreases with increasing reaction pressure, the same solidification point reduction can be reached by raising reaction temperature. While the yield of diesel fraction changes a little. Compared with catalytic dewaxing, the yields and cetane index of diesel are significantly higher in the case of hydrodewaxing when the solidification point of diesel is close.

Key words: paraffinic based, diesel, isodewaxing, catalytic dewaxing, solidification point