Total’s Antwerp refinery is the second largest in Europe – after Rotterdam – and the Group’s largest facility on the Old Continent. The plant has a design throughput of 17 million tonnes of crude oil per year, half of which is shipped from the Middle East. The refinery, located within the port zone of this Flemish city, has benefited from a number of upgrade investments to enable it to meet changing market demand and comply with new regulations. In addition to its two conventional atmospheric distillations units – the basic plant of the refinery, used to separate the various fractions of crude oil (petrol, naphtha, kerosene, etc.) – Antwerp boasts two catalytic crackers that produce petrol from heavier fractions, a desulphurisation unit to treat atmospheric residues (the Group’s only such unit anywhere in the world) and a highly efficient, gas-fired cogeneration power plant that produces electricity (120 MW) and steam at the same time, both of which are used to power various refining and petrochemicals processes on the site. The refinery is also equipped with a steam cracker that produces the ethylene and propylene that are the starting point for many petrochemicals. “A refinery needs energy at practically all stages of its process,” explains Laurent Bourgeois, a Total Refining & Marketing manager. Atmospheric distillation consists in heating the crude to 380 °C. But the temperature required and the amount of energy consumed can vary according to the complexity of the treatment process involved. An extreme case is catalytic cracking, where temperatures can reach 750 °C. The refining segment then accounts for 60% of the Group’s energy consumption.
Another characteristic is that most of this energy is sourced in-house: it comes from the crude oil itself (accounting for 6% of total throughput at Antwerp) and recovery of other hydrocarbons produced during the refining process. “We are constantly looking for ways to improve energy efficiency, i.e. to reduce energy consumption for the same use,” says the general manager of the Antwerp refinery, Tom Schockaert. “Our aim is to achieve optimum valorisation of the crude oil and to comply with the very strict CO₂ emissions regulations laid down by the Flemish regional authorities.” Flanders aims to make its industrial base one of the world leaders, including in terms of environmental performance. And Antwerp is already right up with the best. In order to achieve this, the site first had to be able to evaluate the performance of its various units. To do this, the refining industry uses the Energy Intensity Index (EII), developed by the specialist American consultants Solomon Associates. This indicator refers to the ratio of real energy consumption to the theoretical energy consumption of a standard refinery equipped with the same plant and performing the same treatment processes.
The best way to improve a refinery’s energy efficiency is to equip it with high-performance units using the latest technologies that require less energy and therefore generate less CO₂ emissions. “The cogeneration power plant and the atmospheric residue desulphurisation unit improved the Antwerp refinery’s energy efficiency by ten points,” notifies Laurent Bourgeois. Site management also leveraged the proximity of the various units to capture all possible synergies. For example, the steam cracker, located in the middle of the site, uses naphtha feedstock supplied by the atmospheric distillation unit and supplies steam (in addition to petrochemicals) to the other units on the site.
In addition to these investments, the Antwerp site launched a “back to square one” initiative at the start of this decade, carrying out studies of energy consumption by the various units including breakdown by component equipment (exchangers, furnaces, columns, etc). “These studies showed us where there was potential for better energy efficiency,” explains the refinery’s technical manager Mathieu Soulas. “Then we put in place an annual action plan.”
Most of the energy (70%) used in the refinery comes from recovery of heat and the products of refining processes, and the aim of the plan is to increase this proportion. The refinery’s network of heat exchangers, the matrix of pipes that transport hot and cold chemicals, obviously plays a key role in this. “By installing additional heat exchangers you can recover more calories and reduce the amount of outside energy you require,” adds Mathieu Soulas.
Two projects along these lines have been carried out recently.

Monitoring energy consumption in real time
The energy-efficiency strategy being pursued at Antwerp also involves regular follow-up using appropriate monitoring tools. The key tool here is the monthly statistical report. At the end of each year, monthly targets are established (in terms of EII) for the coming year. Targets are set for the refinery as a whole and also for each individual unit. At the end of each month, actual performance is compared to the initial target and any discrepancies are carefully analysed with a view to taking the necessary corrective measures.
Among the other tools put in place is a system designed to optimise energy consumption in real time. A software programme devised in 2006 allows to calculate the costs involved in the different energy sources being used and to optimise supply at all times. Another tool is a system of “sniffers” developed by technicians at the refinery to detect and measure otherwise invisible steam leakage between the various pipe networks. “This system was put in place in 2004 and has yielded very good results,” comments Sofie Poppe, who is in charge of the refinery’s energy management. “It has enabled us to gain half a point in terms of EII.”
As for the petrochemicals plant, the steam cracker is permanently monitored,the energy efficiency being measured in real time. And with good cause: “The energy factor is even more crucial in this case, because it accounts for 75% of overall costs for the steam cracker,” explains Daniel Leuckx, head of the Total Petrochemicals Europe Energy network. “But there is an up side here too: any improvement in energy efficiency has a multiplier effect.” Implementing such a consumption-monitoring system is a necessity given the stakes involved. “The system tells us the exact energy consumption of the steam cracker, minute by minute. It’s the only one of its kind in the Group today,” boasts process engineer Christophe Thille. The duty operators have to report actual energy consumption of the steam cracker at the end of every 8-hour shift, and if consumption is over target management asks for an explanation. “The main thing is to make operating teams aware of just how important energy efficiency is,” says the steam cracker’s production manager Wim Lefever. “Our system of continuous monitoring acts as a stimulus here because the results of every measure we take are immediately visible.” And with a view to longer-term improvement, an energy-optimisation study is already under way to identify ways to capture greater synergies, especially with the site’s cogeneration power plant.
Over the last ten years, the Antwerp complex has boosted energy efficiency by 15 EII points and the site is now ranked in the top decile worldwide for energy efficiency. But that doesn’t mean they can afford to rest on their laurels. “It’s true that the major gains are all behind is, but experience shows that even the most efficient units can still be improved,” says Tom Schockaert. In brief, rational energy consumption will remain a top priority, “whatever happens in future”.