Industrial Heat Technology

More than 80% of the total energy use within the Dutch industry consists of the need of heat in the form of steam at different pressure levels and for firing furnaces. The total industrial heat use (530 PJ/year) together with exothermic heat from chemical reactions is eventually released to the ambient atmosphere through cooling water, cooling towers, flue gasses, and other heat losses. We call this heat loss ‘Industrial waste heat’. A detailed study of the magnitude of the actively cooled heat by air or water coolers within the Dutch chemical and refining industry revealed the picture below. Yearly, more than 100 PJ of heat from sources > 0.5 MW above 50ºC is actively cooled away within these industrial sectors.  In addition, a much larger waste heat potential is present, especially in not-actively cooled streams (like flue gasses) and other industrial sectors.

A first, most logical, solution to this waste heat problem is to reuse the heat within the same process or at the same site. This kind of heat integration has already been applied to a great extent within the Dutch industry but offers no solution for the waste heat still remaining. The reuse of waste heat is hindered by the fact that:

• The temperature level of the waste heat is too low to be reused again at the same site;
• The waste heat is released at a different time than heat is needed.
• The distance between the source of the waste heat and need of heat are too far apart.

The priority area Industrial Heat Technology tries to develop cost effective technological solutions for these problems mentioned above. Therefore the activities are directed towards the following solutions:

• Upgrading waste heat
  • If industrial waste heat can be upgraded tot process heat of high quality, for example medium pressure steam of 230ºC, large energy savings are possible. Conventional heat pumps are not able to generate the temperature lift necessary (about 100ºC). ECN works on two innovative concepts that are capable to do so.
  • Waste heat can also be upgraded by generating cold out of the waste heat.
• Storage of (waste) heat
  • By storing waste heat in a way that the losses are very low, this waste heat can be reused again at another time.
• Transport of (waste) heat
• If heat can be transported with low losses, heat suppy and demand can be brought together resulting in overall energy savings.