Antwerp cogeneration plant breaks new ground

ExxonMobil's newest cogeneration facility is in Antwerp, Belgium, with 125-megawatt capacity.

A new facility in Belgium uses technology to make productive use of excess heat in the generation of electricity. The result: improved efficiency and reduced emissions.

Startup of a new cogeneration plant at the ExxonMobil Refinery in Antwerp, Belgium, is another major step by ExxonMobil in using energy more efficiently and reducing greenhouse gas emissions.

Inauguration of the facility at Antwerp, ExxonMobil’s second-largest refinery in Europe, expands the company’s interests to about 100 cogeneration installations at 30 worldwide sites, generating some 4,600 megawatts (MW) of additional power. That’s enough electricity to supply the needs of approximately 2 million U.S. homes.

With cogeneration technology, ExxonMobil can produce electricity to power its operations and also capture heat, in the form of high-pressure steam that, in turn, can be used to transform raw materials into a variety of products. Cogeneration provides a more efficient source of power than purchasing electricity from a local utility — in some cases up to 50 percent more efficient.

How it works
Cogeneration starts with the burning of fuel, often natural gas, in a large gas turbine that provides the power to rotate an electric generator.

The hot exhaust gases from the turbine are then routed to a heat-recovery unit that captures additional energy otherwise lost to the atmosphere. Steam from the process is typically used in a refinery’s manufacturing units.

At Antwerp, however, there is only a limited requirement for additional steam, so the excess energy is also used to heat the refinery’s crude oil directly, significantly reducing the energy needed to convert the crude into clean fuels. Using heat this way, on such a grand scale, is what sets the Antwerp Refinery — and its cogeneration unit — apart.

“The Antwerp cogeneration process generates about 125 MW of electricity — enough to power the refinery, as well as the needs of most of ExxonMobil’s other Belgian manufacturing operations,” says Richard Henderson, the refinery’s technical manager.

Moreover, the process is highly energy-efficient, so carbon-dioxide emissions are reduced. In fact, the total impact of this project is a reduction of Belgium’s CO₂ emissions by approximately 200,000 tons a year. Worldwide, ExxonMobil’s investment in cogeneration has lowered greenhouse gas emissions equal to removing more than 1 million cars off U.S. roadways.

Construction in a tight space
Construction of this cogeneration plant presented a special set of challenges.

“The Antwerp refinery is densely built,” says David McLatchie, project executive. “There’s very little extra land available for new construction. Given the small plot space the team had to work with, it was essential to come up with something completely out of the ordinary in order to accommodate this new plant.”

Normally, the two major components of a cogeneration facility — the gas turbine that creates electricity and the heat-recovery unit that generates steam – are built adjacent to each other. At Antwerp, this wasn’t possible, so it was necessary to construct the heat-recovery unit on top of the gas turbine, more than three stories above it.

Construction required high-precision lifting operations from crane operators to get all the equipment in position for assembly. With much of the work being performed in tight conditions high above the ground, developing plans for working safely was paramount.

“We made sure that safety considerations were part of every step of the planning and construction process,” says Gilbert Asselman, refinery manager.

At its peak, construction of the facility employed some 400 people. Commissioning activities began in December 2008, with startup and testing successfully completed in January 2009.

Inauguration day
The Antwerp refinery hosted an inauguration ceremony for the new cogeneration unit in March. It drew more than 200 representatives from government, business, the community and ExxonMobil as well as numerous members of the news media.

Flemish Prime Minister Kris Peeters recognized the company for its additional investment in cogeneration. He also emphasized the importance of energy efficiency in reducing emissions and elaborated on the government’s policy to promote cogeneration.

Hilde Crevits, the Flemish minister of energy and the environment, and Cathy Berx, governor of the province of Antwerp, also attended the event.

Senior ExxonMobil executives included Olivia Owen, corporate vice president for safety, security, health and environment; Darren Woods, refining director for Europe/Africa/Middle East; and Joost van Roost, the company’s lead country manager for Belgium, the Netherlands and Luxembourg.

The inauguration was a memorable launch to an extraordinary project that promises to meet the needs of the Antwerp Refinery and the Belgian people while also helping the environment.