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

In this paper, a multi-stage catalyst-adsorbent reactor consisting of a series of catalyst and adsorbent beds is proposed for an effective tetrafluoromethane (CF₄) abatement and conversion of corrosive hydrogen fluoride (HF) to CaF₂, a useful chemical. Experimentally, enhanced CF₄ conversions were observed in multi-stage catalyst-adsorbent reactors compared to a zero-stage reactor (catalyst bed only) confirming sorption-enhanced CF₄ hydrolysis due to selective removal of HF during reaction. In addition, some useful design guidelines to select the number of stages and a proper time to replace adsorbents are presented. To develop a process simulation model to represent experimental data, Aspen HYSYS^®, a commercial process simulator, was used providing a proper model to match experimental data quite reasonably. Based on experimental and simulative studies, a three- or four-stage catalyst-adsorbent reactor is recommended for CF₄ abatement considering both reactor performance and capital/operating expenditures.