Preliminary techno‐economic analysis of a multi‐bed series reactor as a simultaneous CF₄ abatement and utilization process

Abstract

A preliminary techno‐economic analysis combining process simulation and economic analysis has been carried out to assess the feasibility of employing a new CF4 abatement and utilization process without HF effluent, where CaO was employed to convert produced HF into CaF2, a useful chemical. Moreover, the effect of employing multi‐bed series reactors compared with a single‐bed reactor on CaF2 production was analyzed using Aspen HYSYS® based on material and energy balances from process flow diagrams for three systems, a single‐bed reactor (S‐1), a two‐bed series reactor (S‐2), and a three‐bed series reactor (S‐3). From economic analysis to estimate annual operating cost savings for three systems, it was found that multi‐bed series reactors (S‐2 and S‐3) performed better than a single‐bed reactor (S‐1) due to equilibrium shift by Le Chatelier's principle leading to reduced operating temperatures to produce the same amount of CaF2 as S‐1. Consequently, annual cost savings of about 7 to 13% were obtained in S‐2 and S‐3 compared to S‐1 and this can serve as a useful guideline for the efficient system design. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Experimental and simulation studies for reaction enhancement of catalytic CF4 hydrolysis by consecutive HF removal using a multi‐stage catalyst‐adsorbent reactor

“…Under a steady state condition, a Peng‐Robinson equation of state was chosen for an appropriate thermodynamic fluid package and experimentally obtained CF 4 conversion data from the Korea Institute of Energy Research (53.3, 83.5, and 96.0% at 923, 973, and 1023 K, respectively) were used in conversion reactors. Components such as Ca(OH) 2 and CaF 2 were modelled as hypotheticals based on their thermodynamic properties (molecular weight, 74.09g mol −1 , 78.07 g mol −1 , normal boiling point, 3123 K, 2806 K, and ideal liquid density, 2211 kg m −3 , 3180 kg m −3 , respectively) because they are not in the component library of Aspen HYSYS ® . Two different types of conversion reactors were used with the first one for CF 4 hydrolysis and the second one for the conversion of HF to CaF 2 via reaction with Ca(OH) 2 .…”

Conceptual design of a new SF6 abatement technology using a multi‐bed series reactor for the production of valuable chemicals free of toxic wastes

“…PFCs have relatively high global warming potential (GWP) ranging from 6,500 to 23,900 compared to conventional CO 2 with a GWP value of 1 and among them, SF 6 with a GWP value of 23,900 has been identified as the strongest due to its intensive absorption of infrared radiation and long atmospheric lifetime . Nowadays, many efforts have been paid to reducing these PFCs and various methods like alternative chemicals, capture/recovery/recycle systems, process optimization, and abatement systems are being sought . In particular, abatement technology in a catalytic reactor system using various catalysts is actively under development as the most practical PFCs reduction technology .…”

“…Nowadays, many efforts have been paid to reducing these PFCs and various methods like alternative chemicals, capture/recovery/recycle systems, process optimization, and abatement systems are being sought . In particular, abatement technology in a catalytic reactor system using various catalysts is actively under development as the most practical PFCs reduction technology .…”

“…To overcome these limitations that a conventional system currently has, a new reactor system of employing multi‐bed series reactors containing a catalyst bed for hydrolysis reaction and an adsorbent bed using CaO to react with HF and produce CaF 2 (eq. ) was proposed as a new CF 4 abatement technology and this proposed system successfully eliminated the use of a scrubber thus saving capital and operating costs significantly. …”

“…With strict environmental regulations and efforts to reduce global warming, perfluorinated compounds (PFCs) such as CF 4 [1][2][3], CHF 3 [4,5], C 2 F 6 [6,7], C 3 F 8 [8], and SF 6 [9][10][11][12][13][14][15][16][17][18][19], which are commonly used as etching and cleaning gases in the semiconductor manufacturing, have globally attracted significant attention because they are toxic chemicals and potential contributors to the global warming as greenhouse gases (GHGs) [2,3,9,20,21]. PFCs have relatively high global warming potential (GWP) ranging from 6,500 to 23,900 compared to conventional CO 2 with a GWP value of 1 [21][22][23] and among them, SF 6 with a GWP value of 23,900 has been identified as the strongest due to its intensive absorption of infrared radiation and long atmospheric lifetime [10-12, 19, 20, 24, 25].…”