Energy savings at Aalborg Portland correspond to more than 7,800 households' annual electricity consumption

Each year Aalborg Portland invests millions of Euro in projects aimed at reducing energy consumption in the energy-intensive cement production. Last year, the company uncovered a new potential where surplus heat from Aalborg Portland's largest grey cement kiln, is transferred to the company's five white cement kilns.

The first white kiln has been switched on the new network, and the preliminary calculations show that Aalborg Portland now saves approx. 6,400 MWh per year. It has thus motivated to scale the project to the other white cement kilns with a total savings potential of as much as 30 GWh per year. This corresponds to more than 7,800 Danish households' average electricity consumption per year or 3,500 tons of coal:

• We have worked intensively in recent years to energy optimize the production in Aalborg, and it is fantastic to see the very concrete results that our new ideas and projects have, explains Production Director Søren Konstmann Lausen from Aalborg Portland and continues:
• It’s an ongoing process that requires continuous investment in development projects, and we haven’t finished optimizing our already high-tech and resource-efficient production. There is still a potential for further energy improvements and particularly for utilization of surplus heat, and we expect to be able to unveil more sustainable initiatives in our production in the near future.

In order to realize the project, Aalborg Portland, in collaboration with consultants and manufacturers of machinery, has designed an ingenious system of pipes and wires that pass the surplus heat from kiln to kiln. The new supply network is constructed of more than 250 meters of fully insulated pipes with a diameter ranging from 500 to 1,800 millimeters, a total of approx. 70 tons of pipes and about 60 tons of load bearing steel structures.

In addition to the increased heat utilization between the kilns, Aalborg Portland has also initiated an energy renovation project of the cement kilns, which includes replacement of the refractory bricks that coat the inside of the kilns and prevent the pipes from melting. The new refractory bricks have an increased insulation effect, thereby reducing the need for fuel.

• We have been working intensively to reduce our carbon footprint for many years. Even the lowest hanging fruit can have a great effect in a production plant of our size, which is why we seek to optimize in all corners of our production and our organization, concludes Søren Konstmann Lausen.

Facts about the energy optimization project
Aalborg Portland's largest kiln produces approx. 4,500 tons of cement clinker per day, which is converted into the finished grey cement. In this process, the raw materials are first heated to approx. 1,500 degrees, after which the cement minerals are cooled in a clinker cooler with atmospheric air. This process results in a large amount of excess heat which is returned and recovered in the same kiln.

A small part of the heat from the rear part of the cooler has so far not been recoverable, and it’s this surplus heat that Aalborg Portland can now successfully transfer to the company's five other cement kilns that produce white cement.