A New Process for Synthesis of γ‐Butyrolactone and Cyclohexanone

Abstract

A new process through the coupling of maleic anhydride hydrogenation and cyclohexanol dehydrogenation has been studied for the simultaneous synthesis of c-butyrolactone and cyclohexanone. The possibility of the coupling process has been investigated thermodynamically. The separated hydrogenation of maleic anhydride, the dehydrogenation of cyclohexanol, and the coupling process over the same Cu-Zn-Al catalyst have been carried out in a fixed-bed reactor. Compared to conventional processes, the coupling process has several advantages, e.g., improved c-butyrolactone and cyclohexanone yields, good energy efficiency, and optimal hydrogen utilization. The effects of reaction temperature, n(H 2 )/n (reactants) and liquid hourly space velocity on the coupling process are investigated. One thousand hours of stability testing shows that the Cu-based catalyst has relatively high activity and good stability in the coupling process.

Dimethyl Carbonate Synthesis from Propylene Carbonate with Methanol Using Cu–Zn–Al Catalyst

“…Based on structural, morphology, and textural characterization, it may be said that CZA800 has high crystallinity because of sintering which leads to small specific surface area. This shows that the higher calcination temperature of 800 °C destroys the hydrotalcite structure and decreases the surface area and pore size, although it increases the crystallinity. , Zheng et al and Busca et al have reported BET surface area of 67 m 2 /g for HTLc having Cu/Zn/Al molar ratio of 3.8/1.3/1. Cunha et al, Mehar et al and Venugopa et al have reported BET surface areas of 96, 73 and 57 m 2 /g for Cu/Zn/Al molar ratio of 1.5/0.5/1, 1/1/1 and 6/2.5/1.5, respectively.…”

“…size, although it increases the crystallinity. 50,51 Zheng et al 36 and Busca et al 37 have reported BET surface area of 67 m 2 /g for HTLc having Cu/Zn/Al molar ratio of 3.8/1.3/1. Cunha et al, 28 Mehar et al 33 and Venugopa et al 34 have reported BET surface areas of 96, 73 and 57 m 2 /g for Cu/Zn/Al molar ratio of 1.5/0.5/1, 1/1/1 and 6/2.5/1.5, respectively.…”

“…Few authors have previously synthesized copper–zinc-aluminum (hydrotalcite) based catalysts. They used them for different applications such as methanol or ethanol steam reforming, CO 2 hydrogenation, hydrogenolysis of glycerol, aerobic oxidation and synthesis of various chemicals, etc. − Table shows a comparative assessment of characterization of copper–zinc-aluminum HTLc and their applications. ,− ,− …”

Coupling reaction between methanol dehydrogenation and maleic anhydride hydrogenation over zeolite‐supported copper catalysts

“…However, coupling methanol dehydrogenation with a contradictory hydrogenation reaction is considered an effective way to overcome the disadvantages of the single dehydrogenation process by virtue of the exothermic and hydrogen consumption properties of hydrogenation reactions. Several groups have reported the catalytic coupling of dehydrogenation and hydrogenation reactions where both reactions with the characteristics of heat and hydrogen compensation were carried out over one catalyst simultaneously . For example, Zhu et al found that it is an environmentally benign route to produce γ ‐butyrolactone (GBL) through coupling butanediol dehydrogenation and maleic anhydride (MA) hydrogenation over Cu/ZnO/Al 2 O 3 catalysts in terms of good energy efficiency and optimal hydrogen utilization.…”