Experimental investigations and model-based optimization of CZZ/H-FER 20 bed compositions for the direct synthesis of DME from CO₂-rich syngas

Abstract

Experimental kinetics studies and model-based optimization were performed for the direct synthesis of dimethyl ether (DME) in a wide range of process conditions, including various CuO/ZnO/ZrO2:H-FER 20 bed compositions. This,...

From CO2 to DME: Enhancement through Heteropoly Acids from a Catalyst Screening and Stability Study

“…The ferrierite ( CP914C , SiO 2 /Al 2 O 3 mole ratio 20, SA BET = 400 m 2 g –1 , Zeolyst International ) was calcined at 550 °C for 4 h under air flow to obtain “FERH”. 30 These zeolites were further calcined two times at 750 °C (600 °C h –1 ) for 5 h each (N 2 flow: 5.5 NL h –1 ) to obtain “ZeoL” and “FERL”. Alumina (γ-Al 2 O 3 , AlO x ) and zirconia (monoclinic, ZrO 2 , ZrO x ) were provided by Clariant GmbH and used as received.…”

“…The β-zeolite ( CP814E , SiO 2 /Al 2 O 3 mole ratio 25, SA BET = 680 m 2 /g, Zeolyst International ) was calcined at 500 °C (600 °C h –1 ) for 5 h (N 2 flow: 5.5 NL h –1 ) to obtain “ZeoH”. The ferrierite ( CP914C , SiO 2 /Al 2 O 3 mole ratio 20, SA BET = 400 m 2 g –1 , Zeolyst International ) was calcined at 550 °C for 4 h under air flow to obtain “FERH” . These zeolites were further calcined two times at 750 °C (600 °C h –1 ) for 5 h each (N 2 flow: 5.5 NL h –1 ) to obtain “ZeoL” and “FERL”.…”

“…In comparison, Brønsted sites are more tolerant toward water . Therefore, Brønsted acidic zeolites like ferrierites, beta zeolites, and H-ZSM-5-type zeolites are in the focus of research for the CtD reaction. − Side reactions and deactivation through coking are often mentioned disadvantages of zeolites. , For the MtD, high-surface-area materials can be coated with Brønsted acids. Rojas et al, Schnee et al, and Kozhevnikov et al reported tungstosilicic acid and phosphotungstic acid, both Keggin-type heteropoly acids, as suitable coating materials for the gaseous MtD reaction. − Navarro et al reported the effective use of bifunctional catalysts with heteropoly acid (HPA) coating in the direct DME synthesis from syngas. , For the StD reaction, even core–shell structured catalysts with an HPA-impregnated γ-Al 2 O 3 and a CZA core are reported .…”

“… 26 − 28 Side reactions and deactivation through coking are often mentioned disadvantages of zeolites. 29 , 30 For the MtD, high-surface-area materials can be coated with Brønsted acids. Rojas et al, Schnee et al, and Kozhevnikov et al reported tungstosilicic acid and phosphotungstic acid, both Keggin-type heteropoly acids, as suitable coating materials for the gaseous MtD reaction.…”

Is Direct DME Synthesis Superior to Methanol Production in Carbon Dioxide Valorization? From Thermodynamic Predictions to Experimental Confirmation

“…MtD-Catalyst Preparation. The dehydration catalysts were prepared either by calcination (FER, CP914C, SiO 2 / Al 2 O 3 mole ratio 20, SA BET = 400 m 2 g −1 , ρ FER = 470 kg m −3 , Zeolyst international) at 550 °C for 4 h under air flow 43 or by wet impregnation (HPA@Al, SA BET = 110 m 2 g −1 , Al 2 O 3 : SA BET = 280 m 2 g −1 , ρ HPA@Al = 1,200 kg m −3 , Clariant GmbH; HPA@Zr, SA BET = 90 m 2 g −1 , ZrO 2 : SA BET = 85 m 2 g −1 , ρ HPA@Zr = 1300 kg m −3 , Clariant GmbH), as shown in Figure 1. Wet impregnation was performed by dissolving the respective amount of tungstosilicic acid hydrate (>99.9%, Sigma-Aldrich Co.) in ethanol, which was stirred together with the carrier material at room temperature until dry, followed by overnight drying at 60 °C.…”