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Title: Industry trends indicate need to optimize propylene yield will grow

Journal Article · · Oil Gas J.; (United States)
OSTI ID:5615098

Most new steam crackers will be based mainly on ethane feed. Therefore, it can be expected that the propylene price will approach the ethylene transfer price, particularly in Europe. Consequently, existing crackers using propane and heavier feedstocks will have to operate at lower severity to optimize the propylene yield. The most convenient way to control the P/E product ratio is the coil outlet temperature. Propylene yield is rather insensitive to hydrocarbon partial pressure (steam dilution and outlet pressure). It is also rather insensitive to the residence time of the cracking process. Operation at low steam dilution will be more economical when operating at low severity. Low-residence-time cracking saves on feed. However, feed savings are less for low severity than for high severity. The new, nontubular pyrolysis processes are no panacea for increasing the propylene yield. In certain cases, revamping to improve the propylene yield may be feasible. Normal paraffins give better ethylene yield than iso-paraffins and naphthenes. However, low-carbon-number iso-paraffins and also certain naphthenes have a very high propylene yield. In Europe, and to a lesser extent in Japan, virgin naphtha feedstocks will be replaced by reformer raffinates, naphthas without heartcut, etc. As more different feedstocks become available, the characterization and evaluation of feedstocks, together with process optimization using sophisticated tools, will become more important.

Research Organization:
AM and Associates The Hague
OSTI ID:
5615098
Journal Information:
Oil Gas J.; (United States), Vol. 81:13
Country of Publication:
United States
Language:
English