Louisiana refinery revamp takes advantage of heavy sour argins

The four coking drums of the new delayed coker stand prominently in the complex's east plant. The enclosed coke-conveyer system stretches to the Mississippi River (Fig. 2). Photo courtesy of TransAmerican Refining Corp.

• TransAmerican is working to complete the construction of its new fluid-catalytic cracker. The new FCCU, which will use UOP's MSCC technology, will process residual oil and gas oil to maximize refinery-gasoline output (Fig. 4). Photo courtesy of TransAmerican Refining Corp. [40,522 bytes]

After remaining relatively inactive since 1983, TransAmerican Refining Corp. is revamping its TransAmerican Norco, La., refinery to take advantage of increasing U.S. refining products demand and heavy sour crude margins.

The TransAmerican revamp will add 200,000 b/d of crude distillation to the U.S.

The last large single capacity addition to the U.S. occurred 22 years ago. In 1976, when ECOL Ltd. started up its Garyville, La., refinery, it was the largest grassroots refinery ever built in the U.S. (OGJ, Mar. 28, 1977, p. 91). Marathon Ashland Petroleum LLC currently owns the Garyville refinery.

By the end the project in 1999, the TransAmerican refinery will have invested over $800 million to build one of the more-complex refineries in the country. The TransAmerican refinery will have a Nelson complexity rating of 11.

The rebuilt refinery will use millisecond catalytic cracking (MSCC) technology, licensed from UOP LLC, for its fluid-catalytic cracking unit (FCCU) and have a heavy sour crude distillation capacity of 200,000 b/d.

The project is being constructed in two phases.

Phase I includes construction of a new delayed coker and a two new sulfur-recovery trains. Phase I also includes the revamping of the atmospheric crude unit, three hydrotreaters, and a reformer.

In Phase II, TransAmerican will install a new FCCU, which will include new fractionation facilities, and expand the existing alkylation unit.

History

The Good Hope refinery, owned by Good Hope Refining Co. and built in 1969, began operations as a topping refinery with 6,500 b/cd of crude distillation capacity. At that time, it processed condensate from natural gas fields in a crude unit and a reformer.

John R. Stanley, now president of TransAmerican Energy Corp., purchased the refinery in 1971 to supply his 230 Gasland gasoline stations. In the late 1970s, the refinery underwent a major expansion project, which installed a crude unit, a vacuum unit, a visbreaker, a catalytic cracking unit, a sulfur unit, and an alkylation unit.

In 1980, the refinery proceeded to plan a major upgrade project that would expand its capacity to 300,000 b/d in the summer of 1981 (OGJ, Mar. 30, 1981, p. 82).

The company reorganized twice-when ammonia prices fell in the late 1970s and again when oil prices fell in the early 1980s.

In 1983, the refinery was shut down as a result of bankruptcy proceedings (OGJ, Mar. 21, 1983, p. 83) and remained down until 1994. During this shutdown period, the refinery was maintained at a total cost of $100 million to await improved refining margins.

After significant rationalization of refining capacity in the 1980s, refining utilization increased in the early 1990s. In 1994, the company began rebuilding the refinery to prepare for a restart.

Initially, the refinery refurbished and restarted the vacuum unit along with associated utilities and tankage. These units were onstream from late 1994 until early 1997.

Phase I construction

The initial financing package for the TransAmerican refinery revamp was done in early 1995. Although the financing had not yet been achieved, the refinery started project work in the second quarter of 1995. At this time, TransAmerican expected financing to be complete by the second quarter of 1996.

In mid-1997, TransAmerican Refining's parent company, TransAmerican Energy Corp., was restructured, and the refinery financing was modified to become part of the parent company's financial plan. During this period, construction for the refinery revamp was slowed significantly although engineering and material procurement continued.

Originally, TransAmerican estimated completion of Phase I by March 1998 and Phase II by September 1999.

When work began again in the summer of 1997, most of the engineering and long-lead-time equipment were done. With the positive economics associated with having an FCCU operating as soon as possible, TransAmerican decided to advance Phase II. This decision delayed the completion of Phase I and moved the completion of Phase II earlier.

In the revised schedule, Phase I is to be completed in November 1998, and Phase II's completion is scheduled for March 1999, about 6 months earlier than the original schedule. Although the reformer is in Phase I, it is not scheduled to be completed until early 1999.

Crude units

Fig. 1 [130,829 bytes] shows the refinery configuration after completion of Phases I and II. The atmospheric unit and vacuum unit are currently operating.

• Atmospheric crude distillation unit. The revamped atmospheric crude unit has a capacity of 200,000 b/d of heavy sour crude. According to Glenn McGinnis, TransAmerican Refining Corp. president and CEO, the original atmospheric and vacuum crude units were built in the late 1970s or early 1980s.

The atmospheric crude unit was restarted with minor modifications at a cost of about $6 million. The main scope of work included installing higher-alloy steel in the bottoms piping to accommodate the sour crude, modifying some piping to allow some debottlenecking, adding several new pumps, and adding a new convection section in the heater to increase efficiency.

Heat integration between the crude units and the new coker required some project work while the unit was down. This heat integration will increase the energy efficiency of the refinery.

Although the TransAmerican refinery has another atmospheric crude unit, it is not part of the current project. With the addition of this crude unit, the crude distillation capacity of the refinery would increase to 300,000 b/d.

• Vacuum crude distillation unit. The vacuum unit is a 220,000 b/d unit, which was designed to process heavy resid for the company's visbreaker unit. Because it has been onstream and offstream since 1994, there was little done to it during this revamp.

TransAmerican restarted the vacuum unit in May.

Hydrotreaters

Expansion and refurbishment of several hydrotreating units were necessary to accommodate the high level of sour crude that TransAmerican intends to process. TransAmerican has three hydrotreating units: a naphtha pretreater, a gas oil hydrodesulfurization (HDS) unit, and a distillate HDS unit.

• Naphtha pretreater. The naphtha pretreater can process up to 30,000 b/d of naphtha from the crude distillation unit and the delayed coker. The naphtha product is fractionated in a naphtha splitter for sales, gasoline blending, and reformer feed.

The unit was relocated from another refinery and is being refurbished with new piping and instrumentation. The refurbishment is expected to be completed at the end of October.

• HDS units. The HDS unit is made of two reactor trains with a common hydrogen-recycle system. Each train can treat 30,000 b/cd of either distillate or vacuum gas oil, depending on the processing and product requirements.
• As part of the revamp, TransAmerican has added a new separation section on the back end of one of the two trains and two new high alloy reactors to allow operation at higher pressures.

The gas-oil HDS train will process gas oil from the vacuum unit and the delayed coker. This unit was constructed in the 1980s.

The distillate train will process straight run kerosine, straight run No. 2 fuel oil, and distillate from the delayed coker.

This distillate HDS unit was mechanically complete in September and was started up in conjunction with the delayed coker.

Coker

The coker was mechanically completed in June and started up in September. It processes vacuum tower bottoms into light gas, naphtha, distillate, gas oil, and coke. Fig. 2 [30,549 bytes] shows the new delayed coker.

The delayed coking unit is a modification of the existing visbreaker, which was originally designed as a coker in the late 1970s. At that time, after an evaluation of the cost, the design was changed to accommodate a visbreaker.

The new equipment added as part of the coker includes the coke drums, the fractionator, and the coke-cutting and handling equipment. Combined, the coker and the atmospheric and vacuum distillation units represent a complex that is heat integrated for efficiency.

The coker has a capacity of 75,000 b/d of vacuum-tower bottoms producing 4,000 tons/day of coke.

The coker is an ABB Lummus Crest Inc. design. Fluor Daniel Inc. provided construction management services for the project.

A significant part of the coker project relates to the coke cutting and handling equipment. An enclosed conveyor system from the unit to one of the company's docks on the Mississippi River will move the coke to barges. This system removes the need for onsite coke storage.

Reformer

The reformer is a 12,000 b/d unit that was built in the early 1980s. TransAmerican is using reforming technology from UOP LLC, which raises the octane level of heavy naphtha for gasoline blending.

As a byproduct, the refomer produces hydrogen, which is recycled to the naphtha pretreater and HDS unit.

The work on this unit consists of a major turnaround and reinstrumentation. Work is expected to be completed in early 1999.

Sulfur, hydrogen, utilities

By the end of Phase I, the sulfur unit will be ready to receive the various H ₂S streams in the refinery. Most importantly, hydrogen, utilities, and offsites will be ready to support the refining operations.

• Sulfur unit. The sulfur unit converts the H₂S produced from various units in the refinery into elemental sulfur and water.

There will be two new sulfur trains: one with a capacity of 220 long tons/day of sulfur production and the other with 160 long tons/day of sulfur production. With oxygen enrichment, the total sulfur production can increase to 470 long tons/day of capacity.

The first sulfur train was mechanically completed in June, and the second one is expected to be complete in October.

Both trains were designed by Black & Veatch Pritchard Inc. TransAmerican managed the construction of the units.

• Hydrogen. Although the reformer will produce some hydrogen, it cannot meet all of the refinery's needs. Thus, the refinery purchases some of its hydrogen requirements from Air Products & Chemicals Inc. through a pipeline network that runs through Louisiana.
• Utilities and offsites. Phase I of the project also included a major upgrade to the refinery's utility systems. New water-treating systems, steam boilers, distribution systems, and firewater and sewer systems were installed.

Offsites process piping and tankage systems have been refurbished and returned to service. New flare and new LPG systems were also installed.

Phase II construction

Phase II includes a new FCCU and an expanded alkylation unit ( Fig. 1). Start-up of these units, expected in the second quarter of 1999, will complete the major TransAmerican project.

With completion of Phase II, the TransAmerican facility will have a complexity factor of about 11.0; the U.S. average complexity factor is about 10.5.1 Crude, cracking, and coking capacities for U.S. coking refineries are compared in Fig. 3 [119,869 bytes].

FCCU

The FCCU is scheduled to be completed in March 1999. Because it increases gasoline production, Trans American regards it as a very profitable unit. The FCCU will process purchased atmospheric resid, vacuum gas oil, and coker gas oil. Fig. 4 [40,522 bytes] shows construction of the new FCCU.

TransAmerican chose the MSCC technology, licensed by UOP. This installation is the second commercial application of the technology; the first was at Coastal Eagle Point Oil Co., Westville, N.J. (OGJ, June 22, 1998, p. 53).

According to McGinnis, Trans American chose this technology because it improves yields, has lower operating expenses, and allows direct processing of atmospheric residual feedstocks, a capability that has been further enhanced by the addition of a catalyst cooler.

McGinnis regards the MSCC catalyst flow as an attractive asset. "It looks like it will be a nice unit to operate from the standpoint of the way the catalyst flows and is controlled. You lift it once in the combustor, then the rest of the circulation is by gravity," said McGinnis.

The design capacity of the FCCU is 100,000 b/d. The design, however, accommodates future expansion to 130,000 b/d.

The FCCU gas plant, shown in Fig. 5 [53,293 bytes], includes a catalytic-distillation HDS (Cdhds) distillation tower, which takes heavy cat naphtha from the main fractionator (MF), and a catalytic-distillation depentanizer tower, which takes the rest of the FCC gasoline from the MF.

The Cdhds distillation tower is the first commercial application of Cdhds, licensed by CDTech. The unit will hydrotreat heavy cat naphtha, which has the highest concentration of sulfur. The product will be sent to gasoline blending for improved gasoline quality (OGJ, June 22, 1998, p. 39).

The depentanizer tower incorporates CDHydro technology for pretreating amylenes. It selectively hydrogenates the diolefins and removes mercaptans to prepare the C₅s for the alkylation unit.

The detailed engineering and construction for the FCCU were done by Raytheon Engineers & Constructors Inc.

Flue gas from the FCCU will be scrubbed in a new caustic scrubber designed by Belco Technologies Corp. Belco is supplying TransAmerican its turnkey EDV wet-gas scrubbing system, which includes a stack-and-purge treatment unit. Table 1 [62,931 bytes] shows the design specifications of the EDV system.

Alkylation unit

The sulfuric acid alkylation unit converts light olefins (C ₃, C ₄, C ₅) produced in the FCCU and the coker to high-octane gasoline blendstock.

TransAmerican is expanding the existing 14,000 b/cd unit to a summer capacity of 26,000 b/cd. The scope of work consists of adding additional contactors, refrigeration equipment, and piping, along with some work related to tower debottlenecking.

Stratco Inc. designed the unit and supplied the contactor/settler systems. The process engineering was done by Raytheon, and the detailed engineering was done by Fluor Daniel.

Environment and transportation

Currently, the TransAmerican refinery is operating under both the Louisiana Department of Environmental Quality and EPA operating permits. Like other refineries, it has submitted its Title V application.

All water, air, and solids treating and handling systems have been upgraded to conform to current standards.

Because all permits were kept active since the refinery shut down in 1983, there have been no major permitting issues.

TransAmerican expects to receive most of its crude by ship. It is connected, however, to local crude systems, including the Louisiana Offshore Oil Port (LOOP), which can accommodate ultralarge crude carriers.

The company has five loading docks on the Mississippi River, one of which is used for loading coke. The docks are equipped with a new vapor-recovery system to be used for controlling emission levels during the loading of light liquid products to ships or barges.

The refinery is directly connected to the Colonial and Plantation pipelines, which it can use to ship finished products to the northeastern U.S.

TransAmerican has about 2.3 million bbl of crude-storage capacity and more than 5.8 million bbl of product-storage capacity.

Control

All refinery instrumentation has been upgraded to new digital control systems. A Honeywell TDC3000 will monitor and control the atmospheric crude/vacuum crude/coker complex. The rest of the plant will use a Foxboro I/A (intelligent automation) system.

These systems permit the future installation of advanced control and optimization systems.

Economics

Because of excess U.S. refining capacity, particularly between 1980 and 1985, the refining industry has been viewed by some investors as a risky business. After 1987, however, average Gulf Coast refining margins finally turned positive (more than $1/bbl) after 5 years of negative margins. ²

Today, the U.S. refining industry is characterized by growing demand, low crude prices, and high refinery utilization.

Simon Ward, investor relations manager of TransAmerican, pointed out that while product demand has increased in the U.S., refining capacity has remained relatively flat. API data show that refining utilization has increased from 65% in 1983 to as high as 97% in 1997.

In addition, the TransAmerican refinery will take advantage of margins for heavy sour feedstock. Referring to a graph of 1993-1998 margins between Mayan and West Texas Intermediate crudes, Ward pointed out the upward trend, from January 1995 to present, from less than $4/bbl to almost $6/bbl.

"So over the past 5 years," said Ward, "the margin has been positive, and has averaged about $5/bbl. In spite of higher operating costs, coking refineries enjoy a substantial cost advantage."

"The majority of the Western Hemisphere crude reserves are heavy or heavy and sour," said Ward. "We are anticipating the huge growth of heavy sour production from Mexico and Venezuela."

When Phase II is completed, TransAmerican estimates that the refinery will generate a little more than $270 million Ebitd (earnings before interest, tax, and depreciation) based on prices for this year through the end of July. Operating costs are expected to be about $3/bbl.

References

1. "U.S. & Worldwide Refinery Complexity Analysis," Oil & Gas Journal Energy Database," Jan. 1, 1998.
2. Beck, Robert J., Oil Industry Outlook, 8th edition, 1992-1996, pp. 157-71.

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