Kinetics Studies of Ethylene Oxidation by Potassium Permanganate
Alvin B. Hernandez1, Edralina P. Serrano2 and Ernesto J. del Rosario1
1Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna 4031, Philippines
2Crop Science Cluster, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines
|Ernesto del Rosario|
Ethylene (C2H4) is a gaseous phytohormone that regulates physiological changes in fruits and vegetables; at high concentration it reduces the storage life of these perishable commodities. Ripening of fruits and vegetables can be delayed by ethylene removal from the storage atmosphere using potassium permanganate (KMnO4) impregnated on a suitable porous material. Several materials can be used as KMnO4 carriers for scrubbing ethylene; rice hull ash, lahar (volcanic ejecta) ash and coconut coir dust have been evaluated in the present study.
The ethylene scrubbing efficiency and stability of rice hull ash, lahar ash and coconut coir dust were studied. The oxidation of C2H4 by KMnO4 was found to be approximately first order for the three carriers. Based on the calculated values of the reaction rate coefficients, the most efficient KMnO4 carrier for KMnO4 oxidation was rice hull ash per gram of scrubber followed by lahar ash and then coconut coir dust. Calculated values of the intrinsic rate coefficient indicate that, at the same KMnO4 loading, lahar ash scrubs ethylene more efficiently, followed by rice hull ash and then coconut coir dust. However, in practical terms, the most efficient scrubber is that based on rice hull ash. This material was also found to be the most stable among three carriers based on the color intensity (chromacity) of the reflected light from the scrubber.
Alvin B. Hernandez, Edralina P. Serrano and Ernesto J. del Rosario, “Kinetics Studies of Ethylene Oxidation by Potassium Permanganate Adsorbed on Rice Hull Ash, Lahar Ash or Coconut Coir Dust”, Philipp Agric Scientist 90: 28-39 (2007).