Another activated alumina desiccant question from our 800 Compressed Air Hotline. A manufacturer in Thailand called us because they had severe moisture problems and now his activated alumina desiccant is filled with moisture. “How do I regenerate this activated alumina desiccant?”, asked the engineer.
Activated alumina desiccant is typically regenerated by your compressed air dryer. A heatless or heated compressed air dryer uses hot air or gas to regenerate the activated alumina. The heat removes the small water vapors and droplets that are trapped inside the tiny holes of the activated alumina. For very small applications, we have even heard of customers baking their desiccant in an oven at around 300 to 400 F to regenerate the desiccant.
Unfortunately for our friend in Thailand, his activated alumina desiccant may have seen too much moisture too quickly and is saturated beyond regeneration repair. He can try purging the desiccant a few more times with the air dryer, but if moisture is still appearing downstream of the compressed air dryer, it’s probably time to replace the permanently saturated desiccant and buy new activated alumina.