News | March 19, 1998

YPF Uses Phillips Technology to Maximize Unleaded Gasoline Production

Investing nearly U.S. $30 million in national energy self-sufficiency, Argentina's leading oil company is using Phillips Petroleum Co.'s refining technologies to become an exporter of internationally accepted unleaded gasoline. The now-publicly-traded YPF S.A. is using Phillips Hydrisom and HF (hydrofluoric acid) Alkylation processes at its Luján de Cuyo refinery to produce 157,000 barrels per month, some 25,000 cubic meters (m3) per month, of unleaded gasoline. The Hydrisom unit started operating in December 1996, while the HF Alkylation unit started up in January 1997. Both units are rated at 2,500 barrels per day (b/d) (390 m3/d) capacity. Luján de Cuyo is the second-largest of three YPF refineries, and the only one producing alkylate. It has a throughput capacity of some 120,000 b/d, nearly 19,000 m3/d, of unleaded gasoline (naphthas), diesel fuel (light gas oil), jet fuel, liquefied petroleum gas (LPG) and coke.

Lights on an HF alkylation unit against the Argentine dusk at the YPF Luján de Cuyo refinery. (Photo by Phillips Petroleum)

In addition to Luján de Cuyo, which was recently awarded ISO 9002 certification, other YPF refineries are a 180,000 b/d (28,000 m3/d) facility at La Plata, on Argentina's east coast, and a 25,000 b/d (4,000 m3/d) refinery in Plaza Huincul, in Neuquén Province on Argentina's southwest border. The company also operates La Plata Petrochemical, near La Plata Refinery.

International Trade Impact
The new Phillips-licensed refining units at Luján de Cuyo help assure Argentine alkylate self-sufficiency and produce exportable unleaded gasoline. Before the units came on-line, YPF had to import alkylate to produce unleaded gasoline for domestic use. Gasoline produced at YPF's revamped Luján de Cuyo and La Plata refineries now meets international standards and allows the company to compete overseas. The revamping, completed during the last quarter of 1996 and the beginning of 1997, gave the company's two major refineries a combined capacity of 300,000 bpd (48,000 m3/d). Also, the Luján de Cuyo refinery produces other products, with higher added value, allowing more flexibility in production of gasoline which complies with the strict air-quality standards in the United States and in Europe. Using the alkylate produced by the Phillips Petroleum unit at Luján de Cuyo, all YPF refineries now can produce exportable unleaded gasoline.

Refinery Upgrades
Upgrade work started in 1993 at the Luján de Cuyo and La Plata refineries, with a total investment exceeding U.S. $200 million. Cat crackers and platforming units had been initially revamped at both refineries and a Tertiary Amyl Methyl Ether (TAME) production unit had been set up at Petroquimica La Plata. In addition to the Phillips Petroleum units at Luján de Cuyo, other YPF refinery upgrades included:

  • An isomerization plant at La Plata
  • A gasoline hydrotreater at La Plata
  • Two ether plants: an MTBE plant at Luján de Cuyo and a TAME plant at Petroquimica La Plata.
The new units, some in operation since early 1995, allow an increase in the gasoline's motor octane number without adding lead. They also significantly reduce levels of benzene and aromatic hydrocarbons, olefins, sulfur and nitrogen compounds and other substances restricted in today's environmental fuels, and reduce Reid vapor pressure (RVP), making the gasoline less likely to evaporate. "YPF's goal was to have all its products meet international quality standards and environmental limits so it can compete in the export marketplace," said Abraham Zarzur, Luján de Cuyo Refinery general manager. "We now have met that goal with the help of our new Phillips units."

YPF now sells 85-90 percent of its finished petroleum products in the domestic market, with the balance for export. More than 75 percent of YPF exports go to other Latin American countries. "YPF is a role model for other Argentine companies. For two years running, we have been named the best-managed company in the country," said Zarzur. "We have always been a leader in Argentina, now environmentally as well as economically," he said.

YPF uses HF alkylation to turn feed stocks into unleaded gasoline for export and for domestic use.(Photo by Phillips Petroleum)

All Unleaded Automobile Gasoline
Since October 1993, YPF has produced only unleaded automobile gasoline, using imported alkylate. It also started adding MTBE to its fuels to further reduce smog formation for a cleaner environment. YPF demolished its unused lead additive plant when the new Phillips HF Alkylation unit came online. The old lead plant site now is a smooth, grassy field just up the street from the Hydrisom and HF Alkylation units. Octane-boosting properties of alkylate from the Phillips units at Luján de Cuyo are especially important since Argentine regulations require that the company meet gasoline research and motor octane numbers (RON and MON) individually. Blending alkylate into the gasoline stream increases both octane numbers to acceptable levels. Phillips Hydrisom and HF Alkylation processes give YPF more flexibility to reach specifications and eliminate or reduce the need for additives such as lead.

YPF used to make lead in a building on this lawn until the hydrofluoric acid (HF) alkylation unit in the background made leaded gasoline obsolete. (Photo by Phillips Petroleum)

Until Luján de Cuyo's Hydrisom and HF Alkylation units came on-line, YPF used imported alkylate to produce its Super (95 RON mid-grade) and Ultra (97 RON premium-grade) gasolines. The 87 RON Normal gasoline didn't need alkylate, since the refinery's FCCU can produce straight-run gasoline of 93 to 94 RON. Now, about 26 percent of total production is in the three grades of "2000 line" gasoline -- "Normal 2000", "Special 2000" and "Ultra 2000".

Aviation Gasoline
The new HF Alkylation unit also makes Argentina self-sufficient in producing 100 octane low-lead (100LL) aviation gasoline. Although it contains lead, which is needed in general aviation piston engines and which YPF imports in the quantities needed, the aviation gasoline still needs alkylate to increase octane to the necessary levels. In fact, Phillips Petroleum first commercialized its HF Alkylation process in 1942 to provide high-octane gasoline for military aircraft during World War II.

The low end-point in the Luján de Cuyo Refinery's new fractionation tower is ideal for producing YPF aviation gasoline, while most other refineries would need another fractionator to make enough low-lead aviation gasoline. With the region's small aviation market, the refinery can produce all the avgas needed in two to three days a month. Any more is exportable.

Phillips HF Alkylation Selection
YPF based its decision to use the Phillips Hydrisom and HF Alkylation processes on technical, economic and environmental considerations. Among HF Alkylation unit advantages key to the YPF decision:

    High alkylate octane numbers
  • Attractive process economics
  • Process stability Safety features
  • Minimal environmental impact.
Plant operators said the process has run smoothly and without upsets since start-up despite the usual minor feedstream variations. YPF engineers say its gravity-flow design makes it a very reliable alkylation process.

Phillips Hydrisom Process
YPF uses the Phillips Petroleum-designed Hydrisom process to upgrade C4 olefins by selective diolefin hydrogenation and isomerization, thus producing enhanced feedstock for the HF Alkylation unit. To treat olefin feed to the alkylation unit, the Hydrisom unit selectively hydrogenates butadiene to butene-1 and isomerizes butene-1 to butene-2. Butene-2 is a preferred olefin because it produces alkylate with a higher octane number.

Removing butadiene from the alkylation unit feedstream reduces acid soluble oil (ASO) production, preserving HF catalyst purity and reducing acid consumption.

Phillips HF Alkylation Process
The Phillips HF Alkylation process uses hydrofluoric acid to catalyze the reaction between C4 olefins and isobutane to form isooctane. A Phillips unit uses the difference in specific gravity, or density, between the acid and hydrocarbons to generate circulation in the reactor without using pumps. This design eliminates maintenance-intensive pumps and stirrers, and also avoids the high operating pressures required to move acid catalyst through other alkylation systems. The only pump moving concentrated HF in the Phillips design is the one feeding the acid regenerator circuit.

Process Safety Features
The HF alkylation unit also includes several state-of-the-art safety features, including the Phillips Inventory Management Process (IMP)-a release mitigation package which includes the rapid acid-transfer system to quickly empty the unit in case of a leak. The rapid acid-transfer feature also uses gravity to empty the reactor/settler into a secure storage vessel, allowing transfer to occur even during a power failure.

Acid coolers (heat exchangers) and the alkylation reactor/settler unit are positioned above the storage tank. Should a release occur, the entire acid and hydrocarbon contents of the reactor/settler could be dumped into the storage vessel in only five to eight minutes, YPF engineers said.

Personnel Training, Safety
YPF planners understood the need for proper training and preparation for personnel to start and operate the new units. YPF managers, engineers and operators visited operating HF Alkylation units in the United States and Spain while deciding on the Phillips processes. Operators at first thought hydrofluoric acid was unpredictable. They didn't know what it would do to YPF pump seals or instruments. That's where the Phillips training came in. When start-up crews went to operating HF alkylation units at U.S. and Spanish refineries for training, they saw how those crews handled the units and they knew they could do it as well. Managers from Petrobras, Brazil's national oil company, have visited the Luján de Cuyo units on similar fact-finding missions to select an alkylation system. They were impressed with unit safety and operation. YPF selected the latest alkylation technology from Phillips Petroleum as an investment in safety. The refinery could assure its operators they were working in a secure unit, so they could concentrate on the work at hand without worrying about safety.

All operators working on the HF alkylation unit wear different levels of protective clothing, depending on the tasks they perform. The latest standards of protective clothing include rubber boots, neoprene pants, neoprene jackets with attached gloves, and a safety helmet with face shield and neck drape. Also available for certain tasks are fully sealed neoprene suits with external air connections. Safety showers and eyewash fountains also are located throughout the unit to provide operators easy access to this safety equipment.

Control room at YPF's Luján Refinery. (Photo by Phillips Petroleum)

Remote Controls for Safety
Operations of the Phillips units are controlled from a new, positive-pressure, automated control room. Unit operators monitor and control remote alkylation-unit operations using computerized process controls. Remote-controlled water cannons are set at four key locations around the unit and fixed water sprays are directed at specific vessels. Controlled and monitored from the control room with remote television cameras, streams of water from the cannons can knock down HF vapor in the unlikely event of a release.

Remote controlled water cannon over the HF alkylation unit at YPF's Luján Refinery. (Photo by Phillips Petroleum)

Phillips Assistance
Phillips Petroleum provided basic engineering design, detailed engineering review, fabrication and installation inspections, start-up and operations support for both the Hydrisom and HF Alkylation units.

YPF worked with Phillips Petroleum engineers and representatives as a team in this venture for more than three years. By being onsite for construction and startup support, Phillips personnel were able to assist YPF with the successful completion of this project. "There are always several details to attend to in any start-up, but this one went very smoothly," said Terry Spears, Phillips Licensing project manager. "By visiting other Phillips-licensed HF Alkylation and Hydrisom units before these units started up, YPF engineers knew exactly what they were doing and handled everything in stride."

Future Markets
Argentina is working diligently to improve its international position. YPF plans to continue expanding and strengthening its export position, and now has joint venture partners in Texas, Indonesia, Ecuador and Venezuela. The company has branded gas stations in Argentina, Chile, Peru and Uruguay, and is working with Petrobras on projects in Brazil. The Mercosur agreement-a trade pact among Argentina, Brazil, Uruguay and Paraguay-is very important to YPF because Brazil needs to import most of its oil. That oil used to come from Europe at high cost, but now Brazil, as a Mercosur partner, is getting much of its needed oil and finished products from Argentina.

YPF and Refinery History
YPF was a state-owned company, but was privatized and offered stock shares to individual investors in June 1993. The government no longer manages YPF, although it holds some 20 percent of the stock. In 1996, YPF exported more than U.S. $17 billion of crude oil and finished petroleum products -- or about 7 percent of the country's total exports. YPF annually exports 25 percent of its finished petroleum products, including a monthly average of 100,000 gal of unleaded gasoline. Established in 1941, YPF's Luján de Cuyo refinery has had six major upgrades, including the 1996/97 projects to add the Phillips Hydrisom and HF Alkylation units. YPF now employs more than 575 workers at Luján de Cuyo and has set an industry standard for creating jobs during privatization and reorganization.

Environmental Care
Luján de Cuyo is located in a semi-arid Western Argentine agricultural and wine region some 25 miles (40 km) east of the Andes Mountains. Aconcagua, the Western Hemisphere's tallest peak, is sometimes visible some 75 miles (120 km) to the northwest. Due to limited rainfall and the importance of irrigation to this major farming and wine-producing region, YPF carefully considered potential environmental impacts before selecting the Phillips Petroleum-licensed Hydrisom and HF alkylation processes.

Photo by Phillips Petroleum

In this semi-arid area, Luján de Cuyo managers pay close attention to water quality, which is strictly controlled by two agencies: The General Irrigation Department and the Groundwater Regional Center. To meet these concerns, YPF runs a closed coolant system to clean and recycle most of the water the refinery uses to cool refining process units. Water quality is measured daily at the treatment center, and groundwater is monitored at two test wells on site. The refinery also carefully monitors atmospheric effluents to meet government standards enforced by the Mendoza Government Environmental Protection Department.

By Nick Basta