Determination of optimum dose of adsorbent for PCDD/F removal in the flue gas of a medical waste incineration plant

Abstract

In this study, congener profile and gas/particle partitioning of PCDD/F compounds was investigated and the optimum adsorbent (activated lignite) injection dose for the control of dioxins and furans was determined in a medical waste incineration plant. 99% of the congeners was found to be in particle phase in the flue gas. Especially, congeners with higher chlorine substitution were dominant. Samples were taken at two different points, one in the upstream of activated lignite injection and the other is in the stack. At the first sampling point, particle phase concentration was found to be between 29 and 282 ng N m(-3) (1-21 ng I-TEQ N m(-3)) and gas phase concentration ranged between 0.3 and 4 ng N m(-3) (0.1-0.2 ng I-TEQ N m(-3)). Emission limit of 0.1 ng I-TEQ N m(-3) was not exceeded at the stack where concentrations ranged from 2.5 to 5.52 ng N m(-3) (0.0 to 0.2 ng I-TEQ N m(-3)) and 0.03 to 0.2 ng N m(-3) (0-0 ng I-TEQ N m(-3)) for particle and gas phases, respectively. Optimum activated lignite dosage was determined to be 0.5 kg h(-1). Adsorption on activated lignite is considered as removal mechanisms of gas phase PCDD/Fs in flue gas. In addition to as 99% of these compounds are present in particle phase, they are captured by the bag filter. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.