CHAPTER 13.4OXYPRO PROCESS

Steve Krupa, Larry Richardson, and Jill MeisterUOP LLC

Des Plaines, Illinois

PROCESS DESCRIPTION

The UOP* Oxypro* process is a unique, low-cost, refinery-based catalytic process for theproduction of di-isopropyl ether (DIPE) from propylene and water. The ether DIPE hashigh octane, low vapor pressure, and excellent gasoline blending properties.

The Oxypro process is especially well suited for processing propylene derived from thefluid catalytic cracking (FCC) unit within the refinery. After amine and Merox* treating,the FCC-derived propylene is fed directly along with water to the Oxypro process. Thepropylene and water are converted to DIPE at more than 98 wt % selectivity. The Oxyproproduct has a purity of more than 98 wt % DIPE and a research octane number clear(RONC) and motor octane number clear (MONC) that are comparable to other ethers, suchas MTBE and TAME.

The Oxypro product shows a clear octane advantage over both catalytic polymerizationand alkylation of propylene. DIPE from the Oxypro process generates 112 RONC and 98MONC compared to only 90 RONC and 89 MONC for C3 alkylate and 93 RONC and 82MONC for catalytic polymerization gasoline. The combination of high-octane product andnear 100 percent overall conversion gives the Oxypro process superior performance com-pared to other refinery C3 alternatives.

PROCESS FLOW SCHEME

A simplified flow scheme of the Oxypro process is shown in Fig. 13.4.1. The amine- andMerox-treated mixed-C3 stream from the FCC unit enters the unit and is mixed with make-up water and internal recycle streams of propylene, isopropyl alcohol (IPA), and water. Thecombined streams are processed downflow in a fixed-bed reactor. The reactor effluent issent to fractionation, where the light ends and propane are removed. The propane productmeets typical liquefied petroleum gas (LPG) specifications of less than 5 wt % propylene.The fractionation product is then sent to product recovery, where water, IPA, and DIPE are

13.19

*Trademark and/or service mark of UOP.

Source: HANDBOOK OF PETROLEUM REFINING PROCESSES

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FIG

UR

E 1

3.4.

1O

xypr

o fl

ow s

chem

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13.20

OXYPRO PROCESS

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separated. The IPA and water are recycled to the reactor to maximize DIPE production.The DIPE product has a purity of more than 98 wt %.

YIELDS

The yields from an Oxypro unit designed to produce 96,000 metric tons per year (MTA)[2500 barrels per day (BPD)] of DIPE product are shown in Table 13.4.1. The feedstockused to generate these yields is representative of a mixed propane-propylene stream froman FCC after amine and Merox treating. Specifications typical for an Oxypro unit DIPEproduct are shown in Table 13.4.2.

OPERATING COSTS AND ECONOMICS

The estimated inside-battery-limits erected cost of an Oxypro unit built on the U.S. GulfCoast in 2002 with a capacity to produce 88,500 MTA (2300 BPD) of DIPE is about $26million. Utility requirements for this unit are given in Table 13.4.3.

OXYPRO PROCESS 13.21

TABLE 13.4.1 Oxypro Unit Yield Summary

BPSD kg/h

Feed:Propylene 2,918 10,050Propane 1,239 4,100H2O 328 2,170

Product:LPG 1,300 4,310DIPE 2,500 12,010

Note: BPSD � barrels per stream-day.

TABLE 13.4.2 Typical OxyproUnit Product Specifications

Specific gravity 0.73DIPE, wt % 98Water, wt ppm �100IPA, wt % �0.5C6�, wt % �2Octane:

RONC 112MONC 98

OXYPRO PROCESS

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COMMERCIAL EXPERIENCE

Construction of the first Oxypro unit was completed in mid-2002. The Oxypro processequipment and operating conditions are well within normal refinery boundaries with lowprocess temperatures and reactor pressures similar to hydrotreating units. The reactionchemistry is similar to that of MTBE, ETBE, and TAME ethers units. UOP has designedand licensed more than 700 hydrotreaters and more than 40 MTBE, ETBE, and TAMEunits. (See Chaps. 13.1 and 13.2.) The Oxypro process draws on the expertise of thesedesigns as well as on experience gained in more than 80 years of UOP process commer-cialization.

13.22 OXYGENATES PRODUCTION TECHNOLOGIES

TABLE 13.4.3 Operating Utility Requirements

Power, kWh 537Steam, MT/h (klb/h):

Low-pressure 11.3 (24.9)High-pressure 8.7 (19.1)

Cooling water, m3/h (gal/min) 336 (1,437)

Note: MT/h � metric tons per hour.

OXYPRO PROCESS

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