The perfect mix for the cement industry: Saving money, energy and CO2
When Finland’s only producer of cement, Finnsementti, needed to replace its flue gas waste heat recovery equipment, it turned to Alfa Laval Aalborg for a cost-effective, energy-saving solution with a return on investment of less than a year.
DATE 2023-11-28Finnsementti’s Parainen plant is located on the South-Western coast of Finland. When their existing flue gas waste heat recovery (WHR) boiler reached the end of its lifecycle, project engineer Berndt Karlsson started sourcing for a replacement that had to fit into the existing limited space: “We were looking for a WHR boiler with better output, and the task was complicated because of tight space restrictions.”
The Aalborg WHR boiler solution
With tentative plans to replace their flue gas WHR equipment, Berndt Karlsson contacted Alfa Laval Aalborg’s sales manager Suvi Luoti.
“We agreed to do some evaluations and calculations, and presented Finnsementti with our proposal. The Aalborg AV-6N water tube WHR boiler has an optimised heating surface, improved output, and we were able to design a boiler that fit into the limited space available at the customer site. After follow-up discussions and meetings, they made the decision to replace their WHR equipment and we got the order,” says Suvi Luoti.
Berndt Karlsson says that there were several reasons why Finnsementti chose Alfa Laval Aalborg. “We considered several flue gas WHR solutions. Yet Alfa Laval Aalborg had a customized unit that was cost effective and could be easily installed.”
Reduced costs and CO2 emissions
Finnsementti is now using less water and energy and has been able to reduce its CO2 emissions. Energy recovered from the flue gases is used in district heating for the plant, with excess heat being sold to the local town’s district heating network. Without the WHR boiler solution, oil would have to be burned in a fired boiler in order to create the same amount of heat.
“With the outlet temperature now being lower, less water is needed in the conditioning tower for flue gas cooling. And besides the reduction in our CO2 emissions, we’re saving a significant amount on costs with the WHR boiler compared to generating the same amount of energy with an oil-fired boiler,” says Berndt Karlsson.
In addition, pressure drop is taken into account in the design. With lower pressure drop over the boiler, the fan motor uses less electricity, which saves on energy costs.
Easier maintenance
When it comes to maintenance, Alfa Laval Aalborg’s WHR boiler is convenient, for instance with several manholes in the boiler construction that allow for inspections. In addition, the boiler is equipped with soot blowers for automatic cleaning during operation.
Finnsementti’s maintenance engineer Jörgen Björkqvist was satisfied with the solution. “Alfa Laval Aalborg provided us a tailor made solution where our ideas were taken into account. For instance, it is possible to isolate part of the tube sections during use when necessary.”
A good partner
Our relationship with Alfa Laval Aalborg is very good, in fact it couldn’t be better. We greatly appreciated that we could visit the factory and see the boiler before delivery.
According to Berndt Karlsson, the project ran smoothly. “From the very beginning we have had an open cooperation, and it has been very easy to communicate with the people involved from Alfa Laval Aalborg. The project ran according to the agreed timeline, and it went quickly with no problems.”
The financial aspects match the technical advantages and the smooth implementation of the project. “The return on investment is less than one year,” says a satisfied Berndt Karlsson.
About the Aalborg AV-6N
The Aalborg AV-6N, a water-tube waste heat recovery boiler is a robust, highly efficient boiler, designed to improve overall plant efficiency.
With the Aalborg AV-6N WHR boiler, waste heat from exhaust gas can be recovered from various sources, such as industrial processes and diesel or gas engines to generate steam and/or hot water. With its flexible design, it is easy to install – even in existing facilities.
Fast facts
The customer
Finnsementti Oy is Finland’s only cement manufacturer. The majority of the cement supply in Finland is produced by Finnsementti’s Parainen and Lappeenranta plants. With 100 years of experience, the company produces a consistent quality of cement, and offers a range of concrete admixtures and additives, as well as crushed rock.
The challenge
Finnsementti needed to replace the flue gas waste heat recovery boiler at its Parainen plant. Space for the new equipment was limited by the existing layout of the plant.
The solution
The Aalborg AV-6N water tube WHR boiler was designed for the limited space available and the flue gas conditions at the Finnsementti plant. It recovers waste heat from flue gas, and heats water to 115°C for use in the plant’s district heating system. Excess heat is sold to the local town for district heating.
The benefits
• Return on investment of less than one year
• Manholes and a special tube side design simplify maintenance
• Recovered energy means reduced CO2 emissions and lower fuel costs