Europe’s hidden power: Turning waste heat into profit

Europe's industry and energy sector account for 40% of Europe's total water consumption and nearly a quarter of its final energy consumption.  

Much of this energy is wasted as heat. Europe's surplus waste heat in industries is estimated at nearly 3,000 Terawatt-hours per year - almost enough to heat every house and apartment in the EU.  

An EU project named iWAYs has now developed a technology called the Heat Pipe Condensing Economiser (HPCE) that captures what otherwise would be lost heat.  

A pipe dream becomes reality 

''The whole idea came about from a dream of mine to come up with a concept to enable factories without chimneys, so to eliminate the need for exhausting these dangerous gases to the environment,'' said Professor Hussam Jouhara of Brunel University London and inventor of the HPCE technology. He says the only feasible way to do this is to both recover the heat and condense the volatile compounds and moisture from the stacks.  

Heat Pipe Condensing Economiser 

The HPCE technology is based on heat pipes which are sealed and filled with a saturated working fluid. The fluid transfers the heat quickly and passively from the heated bottom section to the cooled top part.  

In the HPCE, many of such heat pipes are assembled in a specific pattern. A hot exhaust stream passes through and transfers the heat to the upper part, where fresh water collects the heat.  

During this process, condensates run down the pipes and is collected and piped together with other wastewater from the HPCE system to a water treatment plant.  

The treated water will then be reused.   

Manufacturing  

Manufacturing is the largest and most critical sector of Europe´s economy. But its heavy resource usage combined with rising energy prices of up to 40% since 2022 poses a serious challenge to competitiveness.   

''We are going to lower the dependency of that industrial process from the price of the fuel,'' said Prof. Luca Montorsi of University of Modena and Reggio Emilia and the Project Coordinator of iWAYS. ''We can strengthen the industrial process because it will depend much less on the external factors.'' 

The HPCE is designed to recover up to 80% of the heat and reduce up to 60% freshwater consumption. But it's not simple off-the-shelf technology.  To be effective, the system must be built based on the needs of every industry and company.  

''From a design point of view, it's quite demanding,'' said Prof. Jouhara. ''If you look at different factories, you will not have the same composition for the exhausts in those factories.'' He says that they must first know which compounds need to be condensed to then design the HPCE appropriately, basically in groups of tubes. Each of those tube groups will then be responsible for condensing one of the volatiles in the exhaust.  

Demonstration sites 

To test the prototypes in practice three different demonstration sites were installed.  

At the chemical production facility Alufluor in Sweden, the HPCE was built to endure harsh corrosive exhaust gases. The captured heat warms fresh water to more than 60°C and is used to clean equipment like the reactor. The system also reuses the recovered condensate after it is treated to remove fluorides.  

In Italy, the HPCE is achieving good results after just a few months of operation at Keope ceramics. The goal is to recover six gigawatt hours of heat annually. This heat is used to preheat the air for the spray dryer burner, reducing natural gas consumption by about 70 cubic metres per hour.  

''We can say that every hour of operation we are recovering the amount of energy that 20, 30 households use during wintertime,'' said Marco Manfredini, the Technical Manager of Gruppo Concorde SPA.   

At the Tubacex steel plant in the Basque Country, the HPCE is applied to the hot flue gases from the furnaces. The recovered thermal energy is reintroduced to preheat process streams. Early data shows that it can potentially recover up to 30% of the process heat, significantly reducing natural gas consumption and emissions. The condensed steam is treated using advanced membrane systems.  

Using this method, the plant says it can remove around 99% of contaminants, both organic and inorganic. The goal is to recycle up to 95% of all industrial wastewater, moving the site toward a near-zero discharge model.  

The iWAYS concept, now validated across three critical industrial sectors, is aiming to pay for itself within two to three years.