Prof. Witkamp has been awarded the prize for having set in motion the first steps towards a new industrial ecology - Photo: Tomas van Dijk
Professor Geert-Jan Witkamp will receive the DOW Energy Prize on Thursday. His separation technology based on freezing uses only 15 percent of the energy needed for evaporation.
About a quarter of all the world’s energy is used for industrial separation processes, Professor Geert-Jan Witkamp (3mE) estimates. Back in 1995, when the professor came across the accidental effect of salt being separated from a freezing solution, he decided to use the phenomenon as the foundation for a new separation process called ‘eutectic freezing crystallisation’, or EFC for short. Prof. Witkamp discovered that when lowering the temperature of ice slurry, one encounters the crystallisation point (eutectic point) of the salt solution. The salt, which typically sinks to the bottom of the crystallisator, may then be retrieved in pure crystals, while pure water ice drifts on top of it. Although many in the industry regarded freezing as a cumbersome and expensive technology, Prof. Witkamp demonstrated his technology at various sites using a mobile installation on the back of a truck. He showed the energy used for purification could be reduced by some 90 percent.
Fifteen years on, EFC has been demonstrated in mining, the chemical industry, and in manure treatment. Larger installations are now under design. EFC separation, a TU-owned company, tests the technology for Shell, Umicore, BASF and others. “All over the world, Witkamp’s ideas are gaining influence,” said jury chairman, Professor Wim Van Swaaij.
The jury of the DOW Energy Prize also noted that the development of eutectic freezing crystallisation has proved to be a fertile ground for MSc and PhD students: two PhD students graduated with honours, another was awarded the DOW thesis award, and yet another was honored as the best TU Delft graduate. Van Swaaij: “Quality breeds quality.”
Meanwhile, Prof. Witkamp is developing other innovations in process technology. He believes that by combining reverse osmosis to concentrate process streams, with eutectic freezing for separation, a foundation can be laid for creating industrial processes that produce no waste. In Prof. Witkamp’s vision, we will derive our energy from sunlight, harvest organic raw materials from biological processes, and recycle the inorganic materials.
