Imperial Petroleum Recovery Corp.(fka IRECQ)

[overloded]

IMO, it's all a matter of when, not if. 13 long years still hasn't changed my mind.


ExxonMobil finds multiple uses for emulsion-treatment technology

11/06/2000

After experiencing first-hand the benefits of a novel emulsion-breaking technology, ExxonMobil Research & Engineering Co. (EMRE) has signed a marketing agreement with the developer of the technology-Houston-based Imperial Petroleum Recovery Corp. (IPRC)-and is applying the process in varied operational settings, both downstream and upstream.

The process uses electromagnetic radiation in the microwave range to separate stable, difficult-to-break emulsions into oil, water, and solids. ExxonMobil had tested the process on desalter undercarry at its Torrance, Calif., refinery. The application, called MST (Microwave Separation Technology), debottlenecked the desalter and enabled the refinery to increase crude throughput significantly.

The refinery was so pleased with the results that after the merger between Exxon and Mobil late last year, ExxonMobil took a closer look at MST and decided to carry through with its efforts, together with IPRC, jointly to further develop the technology, apply it internally, and license it externally.

In May, EMRE completed a worldwide marketing and development agreement with IPRC for the MST technology. In addition to applying the technology to downstream operations, upstream applications are being considered as well. IPRC retains title to the patents related to the process (it has 1 US and 19 international patents).

How it works
MST is a deceptively simple process. The general concept of using microwave energy to separate emulsions is not a new one, says IPRC, but the firm was the first to realize the necessary changes and developments to the technology to apply it effectively in commercial settings. "Lots of people worked on [microwave-based separation technologies], but they couldn't get the energy safely and consistently into the feed," said IPRC Pres. Brent Kartchner.

According to a paper written jointly by engineers from ExxonMobil and IPRC and presented in March 2000 at the American Institute of Chemical Engineers spring national meeting in Atlanta, "The MST has the potential to economically treat a wide range of crude oil emulsions in the upstream, downstream, and chemical sectors. Benefits include desalter and crude unit water and solids-related maintenance and chemical savings; enhanced crude-unit energy, yield, and reliability performance; and increased desalter operating flexibility."

Kenneth Albinson, ExxonMobil, presented the paper and said, "These emulsions cause multiple problems to operating units, accumulate in refinery tankage, and in many instances have strong negative economics."

The MST process uses a proprietary microwave applicator to destabilize emulsions, facilitating their separation into oil, water, and solids streams.

A transmitter converts electricity to electromagnetic radiation in the microwave range. The units have a 75-kw power rating, says Kartchner, producing radiation with a frequency unlike the one used in a home microwave.

The microwaves then travel through a carefully configured arrangement of wave guides formed into precise shapes and assembled in such a way as to convey the microwaves toward the applicator, where they contact the emulsion feed.

The interior of the wave guides is specially coated with material that facilitates propagation of the microwaves, and the system contains what Kartchner calls "aiming mechanisms" and uses precise angles of reflection. (Think of the way a camera uses a series of mirrors to reflect light onto film.)

Stepper motors keep the radiation moving toward the applicator at the correct rate, said Kartchner. The feed rate to a typical MST unit is 15-30 gpm, The water portion of the emulsion absorbs the applied energy preferentially.

It is this characteristic that destabilizes the emulsion, says IPRC, because heating promotes flocculation and creaming. The MST process accelerates settling. "Disruption of the droplet interface promotes coalescence," said Albinson.

The energy absorbed by the feed increases its temperature by about 50° F., and the typical outlet temperature is less than 200° F. No further heating is applied after the microwaving step. Operating pressure ranges from 20 psig to 50 psig.

The system is effective on most oil-based emulsions, says IPRC, including so-called "rag layers" (the unseparated mixture that remains between the oil and water layers of an emulsion), slop-oil emulsion solids, dissolved air flotation float, API separator sludge, desalter undercarry (the undesirable transport of crude oil out the bottom of the desalter along with the desalter brine), and tank bottoms.

The output from the unit can be separated with either a centrifuge or in a settling tank, depending on the speed of separation needed, says IPRC.

IPRC's MST units are mounted on either 10 ft by 40 ft skids or 48 ft by 8 ft trailers, and thus are mobile and have a small footprint. They are fully automated and can be monitored on operator rounds.

The units are controlled by a sophisticated computer system that can be operated independently or run through a site-wide control system, such as a refinery distributed control system. If there is a problem on the system of any sort, an 80-db horn sounds, as does an alarm on the operator's computer monitor.

Torrance application
Although Mobil was dewatering its crude feed at the Torrance refinery, said Kartchner, the inefficiency of the operation was causing a reduction in crude unit throughput, "wear" problems with processing equipment, and increased costs associated with additional chemical usage.

Mobil decided to review the MST technology and, based on the results of that review, opted for an 8-month test of a trailer-mounted unit. The results of the Torrance test run were included in the ExxonMobil-IPRC paper presented at AIChE.

In a test run, the feed rate to the unit was 629 b/d, consisting of 282 b/d of oil, 317 b/d of water, and 30 b/d of solids.

After separation, the oil stream contained 96.5 vol % oil, 2.5 vol % solids, and 1.0 vol % water; the water stream contained 91.5 vol % water, 8.2 vol % solids, and 0.3 vol % oil; and the solids stream contained 46.3 vol % solids, 44.0 vol % oil, and 9.7 vol % water.

"We blast that stuff apart, give them back oil with less than 2% bs&w [basic sediment and water], so essentially only oil goes backellipse" to the crude unit, said Kartchner. Beyond the separation efficiency, the results of the test run were successful.

By simply debottlenecking the desalter, the refinery has been able significantly to increase oil throughput. "This is because every barrel of water not removed displaces 6 bbl of oil in the crude unit," says Kartchner.

ExxonMobil was so pleased with the results of the extended test that it completed the marketing and development agreement with IPRC and arranged for IPRC to install an MST-1000 (a 1,000 b/d MST unit) at Torrance and operate it for a minimum of 3 years, with an option to extend it for another 3 years.


continued:

http://www.ogj.com/articles/print/volume-98/issue-45/processing/exxonmobil-finds-multiple-uses-for-emulsion-treatment-technology.html