Aqueous-phase hydrodechlorination of model chlorinated organic compounds over Ru/C catalyst

ABSTRACT

Effluents from the pharmaceutical and dye industries contain chlorinated organic pollutants. The effective treatment of such effluents constitutes a challenging task. In this work, 4-chlororesorcinol (PCRE) and 4-chloro-2-aminophenol (PCAP) were selected as model chloro-organic compounds. Catalytic hydrodechlorination (HDC) of PCRE and PCAP in the aqueous phase was investigated in a slurry reactor using commercial carbon supported ruthenium catalyst. HDC reactions of PCRE and PCAP were studied over the ranges in temperature, 313–353 K, H₂ partial pressure, 0.69–2.76 MPa, and catalyst loading, 0.2–1.2 kg/m³. The performance of Ru/C catalyst for hydrodechlorination and ring saturation was promising. The kinetic data were modeled using Langmuir–Hinshelwood–Hougen–Watson kinetics. The HDC reaction of PCRE and PCAP using Ru/C catalyst proceeds via a dual-site mechanism, wherein atomic H₂ reacts with the adsorbed organic substrate. The activation energy for the hydrodechlorination reactions of PCRE and PCAP was 41.6 and 49.4 kJ/mol, respectively.

KEYWORDS:

• 4-Chloro-2-aminophenol
• 4-chlororesorcinol
• hydrodechlorination
• kinetics
• ruthenium

Additional information

Funding

Dipak D. Payal is grateful to University Grants Commission, New Delhi, for the financial support.