Moderate Pressure Hydrocracking: A Profitable Conversion Alternative
Publication Date: 2012-May-04
The IP.com Prior Art Database
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MODERATE PRESSURE HYDROCRACKING:
A PROFITABLE CONVERSION ALTERNATIVE
M. G . Hunter, ProcessManager
TheM. W. Kellogg Co.
D. A. Pappal,Research Associate
Mobil Research and DevelopmentCorp.
C. L. Pesek,Sr. TechnicalServiceRepresentative
Akzo Chemicals, Inc.
The increasing market demand for middle distillates and the need for lower sulfur, cleaner burning transportation fuels has forced the refining industry to consider adding conversion capacity by hydrocracking. Hydrocracking is a highly flexible process option that can be used to convert virtually any refinery stream into value added products. It is particularly well suited to the production of low sulfur high quality middle distillate fuel components and can be integrated synergistically with other conversion technologies such as Fluid Catalytic Cracking (FCC) and coking.
In the 1960's and 1970's, the most common application of hydrocracking was the maximum production of naphtha for gasoline reforming. As the growth in demand for middle distillate products has increased and the demand for gasoline has begun to level off, the application of hydrocracking technology for maximum conversion of vacuum gas oil to jet and diesel fuelhas gained in importance. The maximum conversion of heavy vacuum gas oils to diesel and lighter products has typically required that hydrocracking plants be designed for operating pressures in excess of 2000 psig. The capital costs for both new high pressure hydrocracking equipment and the incremental hydrogen to feed that equipment has made such facilities difficult to justify within increasingly capital constrained operating environments. Operating at less than total conversion can open up opportunities to optimize the relationship between pressure, conversion, catalyst life, hydrogen consumption and product quality leading to substantially reduced capital investmentand highly profitable returns.
Moderate Pressure Hydrocracking (MPHC) is a once-through, single- pass hydrocracking process for the conversion of heavy gas oils to low-sulfur distillates and unconverted oil which is highly upgraded relative to the raw feed. Operating at lower pressure significantly reduces capital investment and results in substantially less hydrogen consumption. Furthermore,the process
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requirements for MPHC are within the range of many existing VGO
desulfurization units. The typical range of operating conditions for MPHC are shown in Table 1.
TypicalHydrocracker Operating Conditions
Conversion,w t . %
70 - 100 20 - 70
- 3000 < 1500
Liquid Hourly Space Velocity 0.5 - 2.0 0.5 - 2.0
Average Reactor Temperature,OF 650- 800 650 - 800
Hydrogen Circulation, scf/bbl 4000- 10000 2000 - 7000
Hydrogen Consumption, scf/bbl 1200- 3500 400 - 1200
Mobil Research and Development Corporation and Akzo Chemicals have been actively engaged in Moderate Pressure Hydrocracking research for...