The increasing industrialisation of developing countries, in particular China and India, is pushing the global refining capacity of existing installations to the limit, and in cases such as Spain, they are nearing saturation point.

Both the G-8 (Organisation of industrialised countries) and the Organisation of the Petroleum Exporting Countries (OPEC) agree in deeming necessary new and more modern infrastructures for the refinery of crude oil in industrialised countries, which must be more efficient than those currently in use.

Yet the imperative is not simply on the greatest efficiency possible. With the legislation oriented towards maximum environmental conservation, today the need to respect the environment means that a new refinery could not be compared to any of those that are presently in existence.

Refineria Balboa has been designed and will be constructed and operated in compliance with the Best Available Techniques (BATs), guaranteeing the use of the latest generation of equipment and processes which, exceeding current efficiency levels, will render a significant reduction in emissions and waste (a greater energy efficiency means a lower fuel consumption and thus lower emission levels).

Configuration alternatives and choices for Refineria Balboa

Choosing a certain refinery scheme depends on two fundamental factors: the market towards which production will be directed and the characteristics of the crude oil which will be refined.

Selection of crude oils for processing

Commercially, crude oil is normally classified according to two concepts of quality: Density (light or heavy oils) and sulphur content (sweet or sour oils).

The first of these classifies the crude oils on the basis of density, normally measured in degrees API (the empirical definition of oil sector), rather than physical units such as g/l. The greater the degree API, the lighter the oil. In this way the distinction is made between:

• Extra light Crude (>39 ºAPI).
• Light Crude (>31-39 ºAPI).
• Medium Crude (>22-31 ºAPI).
• Heavy Crude (10-22 ºAPI).
• Extra heavy Crude (<10 ºAPI)

Sweet and sour crudes are classified by sulphur content. The dividing line between both is normally around 1% of its total weight.

In a great number of cases both criteria coincide, so it is usual to find light crudes that are sweet and heavy crudes that are sour.

The majority of existing reserves are made up of heavy sour crudes, while deposits of light and extra light crudes with a low sulphur content, required in refineries with little conversion capacity, are harder to come by and are running out at a greater speed.

This trend suggests that the design of the Refineria Balboa should contemplate the supply of more readily available lower quality medium and heavy crudes, which require deep conversion processes in order to eliminate the production of residues (fuel oil, asphalt, etc.)

Processing vacuum residue

The initial stage of crude oil processing consists of atmospheric and vacuum distillation. The latter produces so-called vacuum residue which is the raw material used in the manufacture of fuel oil and/or asphalt. When medium and heavy crudes are used, the output in this fraction is very high and, seeing as it is of insufficient quality to satisfy market requirements, the generation of these products is undesirable.
Currently, in the majority of Spanish refineries, the unit most commonly used in the processing of vacuum residue is a visbreaker. It only serves to reduce viscosity, without changing any other properties, and as such does nothing to improve the quality of the fractions. This prevents the paraffin that is produced from being used for anything other than combustion.

All this reinforces the idea of installing a coker unit to process the aforementioned fraction.

The coker eliminates the production of heavy residual oils, converting them into much more valuable fractions. This amounts to a greater output in the form of distillates, as well as producing coke.

Processing vacuum gas oil

In the majority of Spanish refineries, the processing of vacuum gas oil takes place in the fluid catalytic cracker unit (FCC).

The Spanish market, primary target of the Refineria Balboa, has a surplus of gasoline and a strong shortage of kerosene and gas oils. This clearly indicates the need to adopt a hydrocracking conversion scheme which maximises the production of gas oils, rather than using the FCC unit which is designed to maximise the output of gasoline and, what is more, generates a considerable amount of undesirable, low quality heavy products.

Furthermore, another equally important advantage of hydrocracking is the production of higher quality products, at a greater output and in a more environmentally friendly manner; whilst the FCC remains one of the most contaminating units in a refinery (SOx, CO2, NOx and particle emission).

Hydrotreatment versus Caustic soda treatment

During the process of atmospheric distillation a series of fractions are obtained, including LPGs (Liquefied Petroleum Gases; i.e. propane and butane) and kerosene, that in order to comply with required specifications need to be treated to eliminate undesirable substances before storage.

Currently, the procedure used by Spanish refineries is to treat these streams with caustic soda.

Refineria Balboa will use hydrotreatment which, as its name indicates, employs the use of hydrogen. This process is both more effective and less contaminating, as it eliminates the need to dispose of undesirable chemical solutions.

Choice of fuel

In every refinery various combustion processes take place which are designed to provide the energy necessary for each unit in the refinery system.

The fuel used in present day refineries is a mixture of a fuel obtained from the refinery process, known as "refinery gas" (methane and ethanol), and fuel oil, whose primary component is vacuum residue.

Refineria Balboa will replace fuel oil with natural gas as its choice of fuel with the aim of significantly reducing atmospheric emissions. Putting environmental concerns over economic factors, Balboa will only burn gas fuels.

<< Comparative table of emissions for liquid and gas fuels >>

Plan of configuration alternatives

Refineria Balboa's process scheme, configured to take into account the economic, technological and environmental criteria mentioned earlier, can be observed below.

Block diagram of Refineria Balboa

(Click on image to enlarge)

 

BALBAO REFINERY, AWARE OF THE TECHNOLOGICAL AND ENVIRONMENTAL CHALLANGES POSED BY A REFINERY IN THE 21ST CENTURY, AFFIRMS ITS ASPIRATION AND COMMITMENT TO BE A REFERENCE IN THE SPANISH SECTOR.