Application: H-OilRC is an ebullated-bed process for hydrocracking at-mospheric or vacuum residue. It is the ideal solution for feedstocks hav-ing high metal, CCR and asphaltene contents. The process can have two different objectives: at high conversion, to produce stable products; or, at moderate conversion, to produce a synthetic crude oil.
Description: The flow diagram illustrates a typical H-OilRC unit that in-cludes oil and hydrogen fired heaters, an optional inter stage separa-tor, an internal recycle cup providing feed to the ebullating pump, high pressure separators, recycle gas scrubber and product separation and fractionation (not required for synthetic crude oil production).
Catalyst is replaced periodically in the reactor, without shutdown.
Different catalysts are available as a function of the feedstock and the required objectives. An H-OilRC unit can operate for three-year run lengths at constant catalyst activity with conversion in the 50–80%
range and hydrodesulfurization as high as 85%.
Operating conditions:
Temperature 770–820°F/410–438°C Hydrogen partial pressure 1,600–1,950 psi/110–135 bar
LHSV, hr –1 0.25–0.6
Conversion, wt% 50–80
Examples:Ural VR feed: a 540°C+ cut from Ural crude is processed at 66% conversion to obtain a stable fuel oil containing less than 1%wt sulfur, 25% diesel and 30% VGO. The diesel cut is further hydrotreated to meet ULSD specifications using an integrated Prime-D unit. Arab Me-dium VR feed: a vacuum residue from a blend 70% Arab Light-30%
Arab Heavy containing 5.5wt% sulfur is processed at above 75% con-version to obtain a stable fuel oil with 2wt% sulfur.
Economics: Basis 2008 US Gulf Coast
Investment in $ per bpsd 5,100–7,400 Utilities, per bbl of feed
Fuel, 103 Btu 70
Power, kWh 11
Catalyst makeup, lb 0.2–0.8
Installation: There are 13 H-OilRC units, six in operation and four under design/construction, with a total capacity of 19.57 metric tpy. Three ad-ditional references for H-OilDC, the ebullated bed technology for VGO and DAO, add another 11.45 metric tpy.
Reference: “Resid hydrocracker produces low-sulfur diesel from difficult feed,” Hydrocarbon Processing, May 2006.
Licensor: Axens contact
Acid gas
Heater Vacuum bottoms recycle (optional) Vacuum residue coolerAir
Inter stage separator (optional)
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Hydrodearomatization
Application: Topsøe’s two-stage hydrodesulfurization hydrodearomati-zation (HDS/HDA) process is designed to produce low-aromatics distil-late products. This process enables refiners to meet the new, stringent standards for environmentally friendly fuels.
Products: Ultra-low sulfur, ultra-low nitrogen, low-aromatics diesel, kerosine and solvents (ultra-low aromatics).
Description: The process consists of four sections: initial hydrotreating, intermediate stripping, final hydrotreating and product stripping. The initial hydrotreating step, or the “first stage” of the two-stage reaction process, is similar to conventional Topsøe hydrotreating, using a Topsøe high-activity base metal catalyst such as TK-607 BRIM to perform deep desulfurization and deep denitrification of the distillate feed. Liquid ef-fluent from this first stage is sent to an intermediate stripping section, in which H2S and ammonia are removed using steam or recycle hydro-gen. Stripped distillate is sent to the final hydrotreating reactor, or the
“second stage.” In this reactor, distillate feed undergoes saturation of aromatics using a Topsøe noble metal catalyst, either TK-907/TK-911 or TK-915, a high-activity dearomatization catalyst. Finally, the desulfur-ized, dearomatized distillate product is steam stripped in the product stripping column to remove H2S, dissolved gases and a small amount of naphtha formed.
Like the conventional Topsøe hydrotreating process, the HDS/HDA process uses Topsøe’s graded bed loading and high-efficiency patented reactor internals to provide optimum reactor performance and catalyst use leading to the longest possible catalyst cycle lengths. Topsøe’s high efficiency internals have a low sensitivity to unlevelness and are de-signed to ensure the most effective mixing of liquid and vapor streams and maximum utilization of catalyst. These internals are effective at high liquid loadings, thereby enabling high turndown ratios. Topsøe’s graded-bed technology and the use of shape-optimized inert topping
and catalysts minimize the build-up of pressure drop, thereby enabling longer catalyst cycle length.
Operating conditions: Typical operating pressures range from 20 to 60 barg (300 to 900 psig), and typical operating temperatures range from 320°C to 400°C (600°F to 750°F) in the first stage reactor, and from 260°C to 330°C (500°F to 625°F) in the second stage reactor. An example of the Topsøe HDS/HDA treatment of a heavy straight-run gas oil feed is shown below:
Feed Product
Specific gravity 0.86 0.83
Sulfur, ppmw 3,000 1
Ghiyati, Y., “Technology options for LCO upgrading,” ME-TECH, Dubai, January 2011.
Installation: A total of nine units.
Licensor: Haldor Topsøe A/S contact
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Hydrofinishing
Application: Deeply saturate single- and multiple-ring aromatics in base-oil feedstocks. The product will have very low-aromatics content, very high-oxidation stability and high thermal stability.
Description: ISOFINISHING catalysts hydrogenate aromatics at relative-ly low reaction temperatures. They are especialrelative-ly effective in complete polyaromatics saturation—a reaction that is normally equilibrium lim-ited. Typical feedstocks are the effluent from a dewaxing reactor, efflu-ent from hydrated feeds or solvefflu-ent-dewaxed feedstocks. The products are highly stabilized base-oil, technical-grade white oil or food-grade white oil.
As shown in the simplified flow diagram, feedstocks are mixed with recycle hydrogen and fresh makeup hydrogen, heated and charged to a reactor containing ISOFINISHING Catalyst (1). Effluent from the finishing reactor is flashed in high-pressure and low-pressure separators (2, 3).
A very small amount of light products are recovered in a fractionation system (4).
Yields: For a typical feedstock, such as dewaxing reactor effluent, the yield can be >99%. The chemical-hydrogen consumption is usually very low, less than ~10 Nm3/m3 oil.
Economics:
Investment: For a stand-alone ISOFINISHING Unit, the ISBL capi-tal is about 3,500–5,700 $/bpsd, depending on the pressure level and size.
Utilities: Typical per bbl feed:
Power, kW 2.6
Fuel, kcal 3.4 x 103
Installation: Twenty-eight units are in various stages of operation, con-struction or design.
Reference: NPRA Annual Meeting, March 2004, San Antonio, Paper AM-04-68.
Licensor: Chevron Lummus Global LLC contact
START
Base oil product Light ends Process gas Makeup hydrogen
Fresh dewaxed feed
1
4 3
2
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