The effect of calcination temperature on Zn-Al Oxide phase and methanol production over Cu-Zn/Zn-Al Oxide catalyst

Abstract

Methanol is an important chemical widely used as a raw material in the manufacture of petrochemical products [1]. In 1920, BASF developed a commercially available Cr2O3/ZnO catalyst for producing methanol from CO and H2. Currently, ICI (Johnson Mattey) Cu/ZnO/Al2O3-based catalyst is widely used for commercial methanol synthesis [2]. Since then, catalysts using CO2 as a raw material for carbon neutrality have been developed centering on Cu/Zn/Al-based catalysts [3]. In addition, the methanol synthesis reaction can be applied to CCUS (Carbon Capture, Utilization, and Storage) technology development research [4]. The KIST research team has been developing a commercial MeOH synthesis catalyst for the MeOH-FPSO (Floating Production Storage and Offloading) process and is also developing a commercial process for producing MeOH in the distant sea using natural gas and flare strand gas [5]. There are research data on Zn-Al-based methanol synthesis catalysts prepared by Zn-Al oxide catalysts [6].

In our previous study, a Cu-Zn/Zn-Al catalyst prepared by a two-step co-precipitation method of loading Cn-Zn on a Zn-Al oxide support was prepared. It was confirmed that the Cu-Zn/Zn-Al catalyst showed the effect of suppressing Cu sintering at a higher temperature than Cu/Zn catalyst [7].

In this study, the physical and chemical properties of Cu-Zn/Zn-Al-based catalysts and MeOH synthesis reaction results were investigated according to the calcination temperature of Zn-Al supports. The Cu-Zn/Zn-Al oxide catalysts were prepared by a two-step co-precipitation method. The prepared catalyst was analyzed by N2 physisorption, XRD, H2-TPR, NH3-TPD, and CO2-TPD. The methanol synthesis reaction was performed in the fixed bed reactor with a composition of H2/CO/CO2/N2, temperatures of 250 ~ 350 oC, a pressure of 40 bar, and GHSV of 4,444 h-1. As a result of the experiment, various Zn-Al oxide phases were presented according to the calcination temperature of the Zn-Al Oxide support. It was found that the MeOH productivity and Cu sintering tendency were changed according to the Zn-Al oxide phase.