Refining

Crude oil includes a large range of hydrocarbons with different quantities of carbon atoms. The ratio of the components varies according to the place of origin. For example, the oil of Venezuela is rich in long molecules making it thicker, whereas the crude oil from the North Sea is more liquid. To subdivide crude oil into its components, while providing its optimum exploitation, a fractioned distillation (or refining or cracking) is necessary. The various hydrocarbons are separated according to their different boiling temperature. Liquid crude oil is heated up to 400° C at the base of the refining tower and turns into a gas mixture rising up. While they rise, the gases cool down and, according to different condensation temperatures, are separated. Heavier hydrocarbons condensate immediately and are deposited at the bottom. The others rise up and liquefy again at different levels, where they are collected. Residues contain over 20 carbon atoms, condensate first and can be further separated by means of vacuum distillation to produce lubricants, paraffin, wax and bitumen.
Gas-oil contains 14/20 carbon atoms and condensates at a temperature of 250/350°C. It is an oil fuel used to propel diesel engines and for household heating purposes.
Kerosene contains 10/15 carbon atoms and condensates at 160/250°C. It is an oil fuel used to propel jet planes and heating systems.
Naphtha contains 8/12 carbon atoms and condensates at 70/160°. It is a yellow liquid used as fuel and processed to manufacture plastic materials, pharmaceuticals, pesticides and fertilisers. It is also a solvent to treat rubber.
Petrol contains 5/10 carbon atoms and condensates at 20/70°. It is used as fuel for cars and planes but also to manufacture plastic materials and detergents. At 20° C only methane, ethane, propane and butane remain gaseous. Most of them are used as energy sources and to produce petrochemical substances and plastic materials. Butane and propane in particular are used in the production of the fuel called liquid natural gas.

Special reports

  • 18 January 2016

    Ten years of oil demand

    Eni has recently published the 14th edition of the 2015 World Oil and Gas Review...

    23 October 2013

    Carbon Footprint

    A very special footprint...

    13 May 2013

    Small steps, great footprints

    Have you ever wondered how much space is taken up by an apple or a steak?...

  • 10 January 2012

    Shale gas

    Unconventional gas: shale gas

    22 May 2012

    Green chemistry

    Chemistry accompanies man from that day long ago...

    2 May 2006

    Enrico Mattei

    Enrico Mattei reminds us of a tenacious and brave man...

  • 27 September 2012

    Over 7 billion people on Earth

    Demographers have estimated that on 31 October 2011 world population...

    23 September 2019

    Everything is transformed

    At primary school we learn that nothing is created and nothing is destroyed. We have heard this phrase so many…

    2 April 2019

    Italy’s status on renewable sources

    Renewable sources in Italy The Energy Services Operator (GSE) periodically publishes data and statistics on the renewable sources used in…

From the Multimedia section

  • energy

    Classification of reservoirs

    Look

    energy

    World oil reserves at 2018

    Look

    energy

    Laying of a pipeline

    Look
  • energy

    Pipeline under construction

    Look

    energy

    Men at work

    Look

    energy

    Drilling of wells

    Look
  • energy

    Per capita waste generation in EU, 2017

    Look

    energy

    Natural gas: the world top ten importers (2017)

    Look

    energy

    Concentrating Solar Thermal Power (CSP) Global Capacity, 2017

    Look
  • energy

    Classification of reservoirs

    Look

    energy

    World oil reserves at 2018

    Look
  • energy

    Laying of a pipeline

    Look

    energy

    Pipeline under construction

    Look
  • energy

    Men at work

    Look

    energy

    Drilling of wells

    Look
  • energy

    Classification of reservoirs

    Look
  • energy

    World oil reserves at 2018

    Look
  • energy

    Laying of a pipeline

    Look

Facts

  • Orimulsion

    In order to improve supply security, and therefore the diversification of sources to produce electric energy...

    Cracking operations

    At the end of the fractional distillation, long hydrocarbon molecules can be transformed into lighter molecules by means of more…

    Where does energy come from?

    Every day the Earth receives enough solar energy to satisfy the global energy need...

  • Electricity and electrons

    In all electric plants, excluding photovoltaic solar plants, mechanic energy is transformed into electric energy through the same basic procedure...

    Peat and peat-bogs

    The age of coal starts towards the mid 1600s, stimulated by the need for finding an alternative energy source to…

    Geographical distribution of energy

    Every day the Earth receives enough solar energy to satisfy the global energy need. Unfortunately we cannot exploit all this…

  • Some curiosities about methane hydrates

    The melting of the ice cells, not only brings about the release of methane gas, but it also produces another…

    Hydrogen from the sugar cane

    The Centro di Ricerca Interuniversitario per lo Sviluppo Sostenibile (CIRPS) carried out a study in Peru...

    Hydrogen from biomass

    Hydrogen is an energy carrier that allows to generate energy in an environmentally sustainable way...

  • 2 March 2011

    Orimulsion

    In order to improve supply security, and therefore the diversification of sources to produce electric energy...

    Cracking operations

    At the end of the fractional distillation, long hydrocarbon molecules can be transformed into lighter molecules by means of more…

  • Where does energy come from?

    Every day the Earth receives enough solar energy to satisfy the global energy need...

    Electricity and electrons

    In all electric plants, excluding photovoltaic solar plants, mechanic energy is transformed into electric energy through the same basic procedure...

  • Peat and peat-bogs

    The age of coal starts towards the mid 1600s, stimulated by the need for finding an alternative energy source to…

    Geographical distribution of energy

    Every day the Earth receives enough solar energy to satisfy the global energy need. Unfortunately we cannot exploit all this…

  • Orimulsion

    In order to improve supply security, and therefore the diversification of sources to produce electric energy...

  • Cracking operations

    At the end of the fractional distillation, long hydrocarbon molecules can be transformed into lighter molecules by means of more…

  • Where does energy come from?

    Every day the Earth receives enough solar energy to satisfy the global energy need...