tailieunhanh - A study on the kinetics of oxygen reduction focoar

This paper studies the kinetics of oxygen reduction by reducing agent FOCOAR in an airtight minienvironment under isobaric conditions. The kinetics of the reduction process calculated according to the relation vav = [21 % - O 2 C (end) ] / tend, in which vav is average reduction rate, O 2 C (end) is oxygen concentration at the end of the experiment, tend is total time needed for the oxygen reduction experiment. | Vietnam Journal of Science and Technology 55 (5B) (2017) 111-118 A STUDY ON THE KINETICS OF OXYGEN REDUCTION FOCOAR Le Quoc Khanh1, *, Vo An Quan2, Nguyen Thi Hao2, Do Tra Huong3, Nguyen Van Dương1, Le Xuan Que2 1 Tay Bac University, Quyet Tam Ward, Son La 2 Institute for Tropical Technology, VAST, 18 Hoang Quoc Viet Road, Ha Noi 3 Thai Nguyen University of Education, 20 Luong Ngoc Quyen Street, Thai Nguyen * Email: khanhle80@ Received: 11 August 2017; Accepted for publication: 6 October 2017 ABSTRACT In poor oxygenated environments the oxidation and growth of the living organisms are slowed or stopped, so that food is better preserved. The most appropriate method for oxygen depletion in the air-tight minienvironment is oxygen reduction with iron-based reducing agent, which can reduce the air oxygen concentration to about 0 %, and maintain this low oxygen concentration long during storage. This paper studies the kinetics of oxygen reduction by reducing agent FOCOAR in an airtight minienvironment under isobaric conditions. The kinetics of the reduction process calculated according to the relation vav = [21 % - CO 2 (end) ] / tend, in which vav is average reduction rate, CO 2 (end) is oxygen concentration at the end of the experiment, tend is total time needed for the oxygen reduction experiment. Instantaneous reduction rate vred was calculated according to equation vred = ∆ CO 2 /△t, in which ∆ CO 2 is oxygen concentration reduced in time △t, and △t = ti+1 - ti is time interval for oxygen reduction. It is found that vav depends on the quantity of reducing agent FOCOAR, and in certain time interval varies as linear function of reduction time, corresponding to constant vred. The kinetic result allows an estimating the amount of the reducing agent FOCOAR needed for a preserve minienvironment. Keywords: tropical preservation, corn grain, hermetic poor oxygen, FOCOAR deoxidizer. 1. INTRODUCTION Metals produced from oxide ore tend to be oxidized by .