Efficient Potassium Permanganate Impregnated Alumina Beads to Reduce Atmospheric Ethylene

Potassium permanganate absorbent could remove low levels of ethylene from the atmosphere. 

Commonly, Absorption of potassium permanganate onto activated alumina beads by dipping in a saturated solution was maximal at 2 g/100 g after 2 hours at 20 °C and 4 g/100 g after 1 hour at 65 °C.  In our company, we mix the potassium permanganate with alumina materials firstly, then we make the purple beads. Mixed type is better than immersion one, including adsorption ability and even materials. You could find their difference from the look. Please refer to our Youtube(https://www.youtube.com/watch?v=JzXpSymq3-k)

Commercial alumina-based absorbents were found to contain potassium permanganate at  6.0 g to 12.0 g/100 g suggesting many are prepared at elevated temperature. Trials in a closed system at 20 °C and 60% to 70% RH with alumina beads containing potassium permanganate at 4 g/100 g showed a logarithmic decrease in ethylene concentration with 90% of the ethylene removed after 2.5 to 3.0 hours. Relative humidity (RH) had a marked inverse effect on ethylene absorption with reactivity at 100% RH calculated to be 15% of that at 0% RH. Performance of potassium permanganate where ethylene was continually generated by a continuous flow of ethylene at 14 µL·h-1 through the container showed a steady state was attained within 1 hour and maintained for 24 hours. Ethylene removal increased linearly with bead weight and ranged from 30% with 1 g to 90% with 50 g. Examination over 20 days showed a continuing decrease in rate of ethylene removal which after 14 days had declined to 10% of incoming ethylene although 44% of the original level of potassium permanganate still remained in the beads. Calculations based on known endogenous ethylene production rates suggest that at 20 °C and 90% RH, use of a potassium permanganate-alumina absorbent would be beneficial with produce having a low level of ethylene generation. Suitability for larger packages of produce generating higher ethylene levels is questionable as >1 kg of absorbent may be required. 

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