Repsol's facility in Tarragona, north eastern Spain, is a crucial centre for the company's European refining operations. Originally established in the 1970s, the Tarragona refinery has a total capacity of about 150,000 barrels per day.
The new processing plant at the refinery is designed to supply low sulphur automotive gas oil, and represents part of a major effort by the company to meet changing European Union regulations in respect of emissions and the environment.
Repsol YPF is an integrated Spanish oil and gas company with the bulk of its assets located in Spain and Argentina. The company was the product of a 1999 takeover of Argentine energy firm YPF by the Spanish conglomerate Repsol S.A. and is now one of the world's ten largest oil enterprises, employing over 30,000 people worldwide.
REDUCTION OF BENZENE, AROMATICS AND SULPHUR CONTENTS
"From 1997–1999, Repsol set aside $184 million to comply with the European quality requirements."
The new plant at Tarragona is part of an extensive programme by Repsol YPF to meet new environmental standards. From 1997–1999, Repsol set aside $184 million to comply with the European quality requirements in force from 2000. The company had also made a further investment of $526 million by 2005.
The EU specifications concern the reduction of benzene, aromatics and sulphur contents. The gas oil from the plant meets the EU requirements, which came into force in 2005. The standards are intended to reduce fumes and contaminant emissions. This is of particular importance to makers of diesel vehicles.
AUTOMOTIVE GAS OIL PLANT
The new automotive gas oil plant was approved by the company’s internal processes in the last quarter of 1999. Basic engineering had already started by the time this imprimatur had come through. The plant came into operation in the first quarter of 2002. The cost of the plant was estimated at €168 million.
TARRAGONA PLANT PRODUCTION
The hydrocracker (online in 2002) has a capacity of 1.4 million tonnes/year and is fed by more than 900,000m³/y of heavy petroleum fractions. These heavy fractions are then converted into gas oil and other high quality products, such as lubricants and petrochemical naphthas.
"The hydrocracker means Repsol is able to produce ULSD of less than 50ppm sulphur."
The hydrogen unit at the plant is capable of producing 65,000 Nm³/hour. The hydrocracker meant Repsol was able to produce Ultra-Low Sulphur Diesel (ULSD) of less than 50ppm sulphur nearly three years ahead of Europe's 2005 ULSD deadline.
The 25,000 barrels/day hydrocracker unit was installed using refinery technology from Axens. The unit produces middle distillate of just 1ppm sulphur and cetane number over 65, allowing blending upgrades of other diesel stocks. The hydrogen unit is designed for flexible feedstock (natural gas and naphtha).
This has the advantage that if the price of the feedstock fluctuates so that one becomes significantly cheaper than the other, the company can switch its source of supply.
HYDROCRACKING VACUUM GAS-OIL UNITS
The Tarragona refinery now has two hydrocracking vacuum gas-oil units, that transform the oil into lighter products of greater value added and lower sulphur content, which are the base for the production of petrol and diesel oil.
"The Tarragona refinery now has two hydrocracking vacuum gas-oil units."
In addition there is a naphtha desulphurisation unit, where the sulphur is eliminated in the naphtha that is to be used to power the reformed catalytic unit; also two distilled media desulphurisation units, where the kerosene and oil of atmospheric distillation and products from the hydrocracking unit are treated; and a heavy distilled desulphurisation unit, where the heavy vacuum oil is treated, improving the sulphur content specifications.
The product obtained is normally used as a component of fuel-oil of low sulphur content and as a charge for the fluidised bed catalytic cracking.
CHANGING THE BENZENE CONTENT OF NAPTHA FRACTION
Contracts for five projects to upgrade the refinery to meet European environmental standards were awarded to Foster Wheeler in a $32 million deal. The American firm was given responsibility for Engineering, Procurement and Construction (EPC) to reduce the benzene content of the naphtha at the Tarragona plant as well as another Repsol refinery at Puertollano.
The upgrade at both refineries would then process distillates prior to further treatment in a catalytic reformer. This work by Foster Wheeler was awarded in 1999, and was completed by the end of that year.
The Reformer Catalyst Unit treats part of the naphtha obtained in the hydrocracking and atmospheric distillation of the crude oil unit. The unit also has Continuous Catalyst Regeneration (CCR) that allows for improvements in the octane number, and a benzene separation section.
The lead contract for the Hydrocracker Tarragona project was awarded to Technip. Technip staff at the Madrid and Tarragona sites worked on the project. Tecnicas Reunidas was subcontracted to work on the hydrocracker alongside technology provider Axens.
The engineering centre of Technip based in The Hague carried out the engineering and procurement services related to the main utility, a hydrogen unit, on behalf of Carburos Metalicos, the Spanish subsidiary of Air Products. Technip and Air Products have a global alliance, which has meant they have worked on similar contracts before.
A small Spanish firm called Alatec was also employed during the project as consulting engineers.