Influence of hydrocarbons on hydrogen chloride removal from refinery off-gas by zeolite NaY derived from rice husks

Christina May C Tolentino; Mark Daniel G de Luna; Cybelle M Futalan; Angelo Earvin Sy Choi; Ferdinand G Manegdeg; Nurak Grisdanurak

doi:10.1016/j.scitotenv.2020.138782

Influence of hydrocarbons on hydrogen chloride removal from refinery off-gas by zeolite NaY derived from rice husks

Sci Total Environ. 2020 Aug 1:728:138782. doi: 10.1016/j.scitotenv.2020.138782. Epub 2020 Apr 19.

Authors

Christina May C Tolentino¹, Mark Daniel G de Luna², Cybelle M Futalan³, Angelo Earvin Sy Choi⁴, Ferdinand G Manegdeg⁵, Nurak Grisdanurak⁶

Affiliations

¹ Energy Engineering Program, National Graduate School of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines.
² Energy Engineering Program, National Graduate School of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines; Department of Chemical Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines. Electronic address: mgdeluna@up.edu.ph.
³ School of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University, Manila 1002, Philippines.
⁴ University Core Research Center for Disaster-free and Safety Ocean City Construction, Busan 49315, Republic of Korea.
⁵ Energy Engineering Program, National Graduate School of Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines; Department of Mechanical Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines.
⁶ Center of Excellence in Environmental Catalysis and Adsorption, Faculty of Engineering, Thammasat University, Pathumthani, 12120 Thailand. Electronic address: gnurak@engr.tu.ac.th.

PMID: 32570332
DOI: 10.1016/j.scitotenv.2020.138782

Abstract

The removal of gaseous hydrochloric acid (HCl) in refineries and petrochemical plants is essential to prevent potential catalyst poisoning, equipment corrosion, and several associated public health and environmental hazards when the acid contaminates the hydrogen-hydrocarbon feedstock. In the present work, the effect of alkanes, alkenes, and liquid aromatic hydrocarbons on the removal of HCl from refinery off-gas using zeolite NaY was evaluated. Zeolite NaY was synthesized from rice husks via a hydrothermal route. Adsorbent characterization analyses such as XRD, SEM-EDS, FT-IR, BET and particle size distribution were employed. Fixed-bed experiments were operated under feed condition of 600 ppm HCl and gas hourly space velocity of 640 mL/h·cm³. Gaseous HCl was combined with H₂, H₂-alkanes and H₂-alkenes to simulate the main components of refinery-off gas. Experimental breakthrough curves were used to determine the adsorption capacities of zeolite NaY pellets at breakthrough and saturation. HCl removal by fresh zeolite NaY was inhibited by light alkanes but improved in the presence of alkenes. The adsorption capacity at breakthrough for fresh zeolite with combined hydrogen and light alkenes was measured at 0.1507 g/g. In the presence of aromatics, significant reduction in adsorption capacities to 0.1247, 0.1379 and 0.1437 g/g were obtained for adsorbents subjected to H₂, H₂-alkanes and H₂-alkenes respectively. Zeolite NaY consistently showed higher performance for HCl removal in the presence of H₂ feed mixed with light hydrocarbons compared with a commercial adsorbent.

Keywords: Alkenes; Breakthrough curves; HCl gas management; Hydrocarbons; NaY zeolite; Rice hulls.