A photo detector created by Washington University-St. Louis student has been adapted to automatically shutdown reactors at CEBC.
Researchers at the Center for Environmentally Beneficial Catalysis (CEBC) are developing a process to retain homogeneous catalysts inside reactors for easy reuse. This is especially important for expensive precious metal catalysts.
The new CEBC process involves flowing reaction liquid through a filter. This separates the catalyst from the liquid, just as coffee filters separate the grounds from coffee. The problem is that the filter can become clogged. This causes liquid to fill up inside the vessel, leading to unsafe pressure levels and reaction failure.
Chemical engineers must closely monitor reactors to prevent this from happening. But, engineers, like airline pilots, can only stay awake to “reactor-sit” for so long. Jing Fang, CEBC postdoc, said that “24 hours is the max. That’s the longest I can go without sleeping.” Fang would like to operate her experiments for longer than this, but can’t -- that is, until now.
Sean Mueller, a CEBC student at Washington University in St. Louis, created a device that detects changes in liquid behavior inside reactors. Mueller traveled to Kansas University in June to set up his detector to help Fang and her colleagues automatically monitor the flow of liquid through catalyst retainment filters.
Here is how Mueller’s photo detector works. A fiber optic cable is installed inside a reactor and then attached to a light source and a voltmeter. Light travels through the cable into the reactor. The voltmeter measures changes in refraction of the light. When the experiment is working as designed, the tip of the cable is surrounded by vapor. But when the filter is clogged, liquid rises and surrounds the tip. This changes the current detected by the voltmeter, which then signals a computer to shutdown the system.
“This photo detection idea has been around a long time,” said Mueller. “This is just a new application of it that I developed for my own experiments.”
The photo detector is good news for sleep deprived KU researchers who can now safely rest during long-term experiments.
--Story by Claudia Bode