Hydrodeoxygenation of 2-methoxy phenol: Effects of catalysts and process parameters on conversion and products selectivity

Abstract

The hydrodeoxygenation (HDO) of 2-methoxy phenol (MP), a lignin-derived compound, has massive prospective for valuable compounds production. The lignin derived model compounds can be used for production of green chemicals. The model compound MP conversion into cyclohexane was investigated over Ru metal loaded on various supports (ZSM-5, Y-zeolite, β-zeolite, COK-12, mordenite, ZrO2, and TiO2). The catalytic properties such as the acidic sites, pore size, and morphology influenced the HDO activity and selectivity of the cyclohexane. The yield of cyclohexane increases up to optimum acidity further increases the acidity of the catalyst, the product yield decreased. The experiments carried out at temperature range of 200–300 °C, and 1–25 bar hydrogen pressure in a fixed bed reactor. The parameters greatly influenced the HDO as well as the cyclohexane yield, selectivity, and MP conversion. The highest conversion (100%) and yield of cyclohexane (99.0%) observed at 250 °C under pressure of 20 bar with Ru/ZSM-5 catalyst. Further the recyclability and stability have been checked and observed that Ru/ZSM-5 is stable up to 200 h and displayed excellence activity in both HDO and cyclohexane selectivity. Weight hourly space velocity (WHSV) was investigated (0.5–1.5 h−1). The suitable WHSV found for HDO of 2-methoxy phenol and cyclohexane yield was 1 h−1. The reaction mechanism showed that the Ru/ZSM-5 catalyst provoked the HDO compared to the others catalyst.