Oil

To meet new energy standards, we are committed to making our French refineries more efficient and cost-effective. As part of that drive, the DHC built at our Normandy refinery and inaugurated in March 2007 has increased the production of clean diesel fuel. It was the biggest project of its kind that France had seen in 20 years.

Adapting to new consumption patterns

At 30 million metric tons, France is Europe's top diesel fuel consumer, and national production - 20 million metric tons - is unable to keep up with demand. Compounding the problem, European Union standards setting maximum sulfur content have become much stricter: diesel fuels are now limited to 10 parts per million (ppm) of sulfur, versus 2,000 ppm ten years ago. These changes create a need for new installations. That's why we built a distillate hydrocracker (DHC) at our Normandy refinery, near Le Havre, France. For the same amount of throughput, the DHC increases the output of "clean" diesel fuel by 8%, for a total investment of about €550 million.

A DHC for lighter products with the help of hydrogen

A distillate hydrocracker (DHC) is a furnace, reactor and distillation column all rolled into one. Heavy distillates from the initial refining operation are heated in the furnace in the presence of hydrogen. They are then fed into the reactor, where the large hydrocarbon molecules are cracked into smaller ones. But the resulting lighter mixture must be further refined to separate its different constituents. A pass through a separator removes the sulfur, which is collected in a sulfur recovery unit (SRU). The distillation column is then used to separate the remaining compounds, which include LPG, naphtha for petrochemical production, jet fuel, "clean" diesel fuel for diesel engines, high-grade bases for lubricants and specialty fluids and, finally, residues known as bottom fractions.

The hydrogen required for the process is extracted from natural gas in a dedicated unit known as a steam methane reformer (SMR), to date the technology with the lowest carbon emissions.

The entire installation was of course connected to the refinery's existing units.

Environmental protection and safety

The distillate hydrocracker (DHC) was installed at the very center of the refinery to avoid expanding the complex's safety perimeter. The refinery continued to operate throughout the construction period, with heightened safety procedures.

Everything possible was done to minimize the environmental impact of this major project. Sulfur dioxide, nitrogen oxide and particulate emissions were held down, stormwater and polluted water were separated, a tank for observing water prior to discharge was installed, the DHC's odors were neutralized through vapor recovery, and major equipment was insulated to dampen the associated noise.