The newly appointed assistant professor, Elif Genceli-Güner, developed a technique that separates salts from liquids by freezing the mixtures. It can potentially save huge amounts of energy and water.
From potato starch producers to waste processing plants and mining companies, all kinds of industries that have to deal with waste and process streams with dissolved salts in them can clean up their production and recuperate valuable salts much more efficiently, says Professor Elif Genceli-Güner, if only they would use her ice machine, or, as she likes to call it, her recently scaled-up crystallization method.
Genceli-Güner (33), who is Turkish, developed an Eutectic Freeze Crystallization (EFC) technique together with her departmental colleagues. She recently graduated cum laude for her work on this technique, which cools a liquid until it reaches the so-called eutectic point. At this point the water and the salts in the solution crystallize simultaneously. Scrapers that rub along cooling elements, like in a sorbet machine, create an emulsion of ice and crystallized salts. Gravity does the rest: the lighter ice floats and the salts sink, resulting in a perfectly layered separation.
Genceli-Güner’s main focus was the retrieval of magnesium sulfate from aqueous solutions, a process she devised for mining company Nedmag (her main research sponsor). Magnesium sulfate (MgSO4) is produced when flue gasses from power plants are ‘desulphurised’ to prevent sulpher dioxide (SO2) polluting the atmosphere. The SO2 is absorbed in a solution of magnesium hydroxide, resulting in a solution containing MgSO4. This chemical can be reused as a fertilizer, hence the interest of Nedmag.
But not only Nedmag is interested. Next year Genceli-Güner will also collaborate with researchers from South Africa, where water is scarce, and in the mining industry they need a lot of it. Many minerals are retrieved by pumping water under high pressure in the ground. When it resurfaces the water contains minerals and salts, such as all kinds of sulfates, carbonates and chlorides. After undergoing the Eutectic Freeze Crystallization technique, that same water could then be used over and over again.
Freezing techniques are already widely used in the industry, but then only to create solutions with a higher salt concentration. The higher the salt concentration gets, the harder it gets to freeze the water. At a certain point the process is stopped because of the high energy costs. Other techniques that are widely used in combination with freezing or separately are evaporative crystallization and anti-solvent crystallization, where chemicals are added to a solution to make the salts precipitate.
In her dissertation Genceli-Güner shows that – contrary to what many researchers believe – Eutectic Freeze Crystallization is in fact very energy efficient. “The technique requires 90 percent less energy than conventional evaporation crystallization and theoretically results in 100 percent yield”, she says. “Once you reach the eutectic point nature takes over. When the salts crystallize, the solution becomes more diluted, so it can freeze more easily. Under sufficient cooling, the system directs itself to eutectic temperature and stays around that point; hence, you end up with almost 100 percent perfect salt and ice crystals.”
Last month Genceli-Güner received a Veni grant worth 250,000 euro from the Netherlands Organisation for Scientific Research (NWO) to conduct research on ‘Ice and Mineral Salt Formation below Zero Degrees’. She will now look for a way to calculate the eutectic points in solutions containing salt mixtures, amongst others.
But she will use her grant money for something completely different as well. In 2007, while studying the crystallization process of Magnesium sulfate, she discovered that this chemical, which is usually found in a hydrate form, was surrounded by 11 water molecules (MgSO4·11H2O) at sub-zero degree temperatures. Since 1837 to her discovery in 2007, it was thought that the hydrate contained 12 water molecules. Together with Japanese researchers, Genceli-Güner also discovered the hydrate existing in the wild (a prerequisite for the International Mineral Association to accept a molecule as a mineral), in Antarctic ice cores of several kilometers deep. The hydrate is now known as Meridianiite. With her Veni grant, Genceli-Güner will continue her hunt for new minerals.
Het is 1950. In het hoofd ontvouwt zich een scène uit een ouderwetse Hollywoodfilm. Een zangeres in lange, elegante jurk bekleedt het podium van een rokerige bar. Op de achtergrond figureert een rijtje muzikanten (koperblazers, ritmesectie) in strak pak. Wat belangrijk ogende mannen drinken whisky en roken sigaar. Even verderop dansen stelletjes op een glimmende eikenhouten vloer.
Het is die bijna tastbare sfeer die de oren binnendruppelt als je de muziek van Groover Big Band beluistert. Klassiekers als Nat King Cole’s ‘Orange Colored Sky’ en Sinatra’s ‘Come Fly With Me’ (gezongen door zangeres Suzan Heykoop), smaken naar vervlogen tijden. Bekende latinnummers (‘Mas Que Nada’, ‘Manteca’) roepen ondertussen Caribische sferen op. Maar ook modernere exercities zijn te horen. Goed voorbeeld is het door dirigent Peter Habraken zelf geschreven ‘Color Orange’ dat klassiek begint, spontaan evolueert tot samba en eindigt met twee plezierig concurrerende saxofoonsolo’s. Voer voor de fijnproever; het album van de Groover Big Band smaakt naar meer.
“We hebben het album tussen de matten opgenomen”, vertelt Koen Hermans (pianist en bandcommissaris). Die matten lagen in de Taikwandozaal (groot genoeg om een bigband in te persen) op de zolder van opnamestudio Funky Horn in Rijswijk. Daar namen ze de plaat in een dag op. Dat ging niet op de gebruikelijke manier: niets instrument voor instrument inspelen om daarna alles af te mixen. Om kosten te sparen ging alles op een muzikaal veel interessantere wijze: in één keer. “We hadden per nummer gemiddeld twee takes nodig.”
Ondertussen zijn de kosten er gelukkig bijna uit; er zijn al 250 cd’s verkocht. Veel exemplaren gingen naar de bij de cd-presentatie in het sportcafé aanwezige familieleden en vrienden. “En we hebben natuurlijk aardig wat exemplaren verkocht aan verenigingsgenoten.”
De cd is ook bedoeld als promotie. Hermans: “We kunnen nu makkelijker laten horen wat we kunnen. Zo maak je sneller een afspraak om bij een bedrijf te spelen. Ook kom je makkelijker binnen bij een concours.” Groover doet dit jaar voor het eerst mee aan het nationale big band concours. “We zitten meteen bij de beste tien amateurs.” Wel is Hermans bang dat Groover weggespeeld wordt door semiprofessionele bands. “Toch maken we kans. Wij spelen relatief spetterende nummers en laten daarmee een goede indruk achter. Veel andere bands doen meer ouderwetse jaren dertig swing. Wij spelen ook pittigere funknummers.”
De band oefent zo’n twee uur per week. “We hebben nu ongeveer tachtig nummers op ons repertoire. We zijn constant bezig met nieuwe nummers. Steeds een beetje moeilijker.”
Toch is het lastig om die stijgende lijn te bewaren. Als studentengezelschap kent Groover een groot verloop. “Elk half jaar wisselen ongeveer twee mensen. We zijn op dit moment nog op zoek naar een gitarist en trombonist.” Sommige plekken zijn makkelijker te vullen dan andere. “Er zijn bijvoorbeeld veel mensen die altsaxofoon spelen, maar een trombonist is lastig te vinden.”
Voordat hij bij Groover kwam, luisterde Hermans niet zoveel naar dit type muziek. “Maar door het spelen raak je gemotiveerd en ga je luisteren. Nieuw repertoire komt ook vanuit onze leden; iemand hoort iets en denkt: dat zou gaaf zijn om te spelen.”
From potato starch producers to waste processing plants and mining companies, all kinds of industries that have to deal with waste and process streams with dissolved salts in them can clean up their production and recuperate valuable salts much more efficiently, says Professor Elif Genceli-Güner. If only they would use her ice machine, or, as she likes to call it, her recently scaled-up crystallization method.
Genceli-Güner (33) developed an Eutectic Freeze Crystallization (EFC) technique together with her departmental colleagues. She recently graduated cum laude for her work on this technique, which cools a liquid until it reaches the so-called eutectic point. At this point the water and the salts in the solution crystallize simultaneously. Scrapers that rub along cooling elements, like in a sorbet machine, create an emulsion of ice and crystallized salts. Gravity does the rest: the lighter ice floats and the salts sink, resulting in a perfectly layered separation.
Genceli-Güner’s main focus was the retrieval of magnesium sulfate from aqueous solutions, a process she devised for mining company Nedmag (her main research sponsor). Magnesium sulfate (MgSO4) is produced when flue gasses from power plants are ‘desulphurised’ to prevent sulpher dioxide (SO2) polluting the atmosphere. The SO2 is absorbed in a solution of magnesium hydroxide, resulting in a solution containing MgSO4. This chemical can be reused as a fertilizer, hence the interest of Nedmag.
But not only Nedmag is interested. Next year Genceli-Güner will also collaborate with researchers from South Africa, where water is scarce, and in the mining industry they need a lot of it. Many minerals are retrieved by pumping water under high pressure in the ground. When it resurfaces the water contains minerals and salts, such as all kinds of sulfates, carbonates and chlorides. After undergoing the Eutectic Freeze Crystallization technique, that same water could then be used over and over again.
Freezing techniques are already widely used in the industry, but then only to create solutions with a higher salt concentration. The higher the salt concentration gets, the harder it gets to freeze the water. At a certain point the process is stopped because of the high energy costs. Other techniques that are widely used in combination with freezing or separately are evaporative crystallization and anti-solvent crystallization, where chemicals are added to a solution to make the salts precipitate.
In her dissertation Genceli-Güner shows that – contrary to what many researchers believe – Eutectic Freeze Crystallization is in fact very energy efficient. “The technique requires 90 percent less energy than conventional evaporation crystallization and theoretically results in 100 percent yield”, she says. “Once you reach the eutectic point nature takes over. When the salts crystallize, the solution becomes more diluted, so it can freeze more easily. Under sufficient cooling, the system directs itself to eutectic temperature and stays around that point; hence, you end up with almost 100 percent perfect salt and ice crystals.”
Last month Genceli-Güner received a Veni grant worth 250,000 euro from the Netherlands Organisation for Scientific Research (NWO) to conduct research on ‘Ice and Mineral Salt Formation below Zero Degrees’. She will now look for a way to calculate the eutectic points in solutions containing salt mixtures, amongst others.
But she will use her grant money for something completely different as well. In 2007, while studying the crystallization process of Magnesium sulfate, she discovered that this chemical, which is usually found in a hydrate form, was surrounded by 11 water molecules (MgSO4·11H2O) at sub-zero degree temperatures. Since 1837 to her discovery in 2007, it was thought that the hydrate contained 12 water molecules. Together with Japanese researchers, Genceli-Güner also discovered the hydrate existing in the wild (a prerequisite for the International Mineral Association to accept a molecule as a mineral), in Antarctic ice cores of several kilometers deep. The hydrate is now known as Meridianiite. With her Veni grant, Genceli-Güner will continue her hunt for new minerals.
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