Enhanced Conversion in the Direct Synthesis of Diethyl Carbonate from Ethanol and CO₂ by Process Intensification

Abstract

To overcome the low equilibrium conversion in the direct synthesis of diethyl carbonate from ethanol and CO 2 under moderate reaction conditions, the reaction was conducted in a membrane reactor packed with pelletized Cu-Ni:3-1 supported on activated carbon. A SiO 2 /g-Al 2 O 3 commercial membrane and zeolite A membranes synthesized on commercial Al 2 O 3 supports were evaluated in the membrane reactor. Although characterization of the membranes by X-ray diffraction confirmed the presence of a zeolite A layer on the supports, gas permeation and permselectivity tests of ethanol and water evidenced some defects of the synthesized membranes. An increase in conversion with respect to a conventional packed-bed reactor was observed in the membrane reactors prepared on Al 2 O 3 , but equilibrium conversion was not attained. However, with the commercial membrane, the ethanol conversion was higher than the equilibrium conversion.

Energy‐Saving Separation of the Ethanol‐tert‐Butanol‐Water Azeotrope System Based on an Ionic Liquid

“…According to the COSMO-SAC model, the infinite-dilution activity coefficient of the corresponding system in different ionic liquids was calculated, and the selectivity S ij 1) of the ionic liquid to the system was obtained. The calculation formula of S ij is as follows [Eq.…”

“…Ethanol) and tert ‐butanol (TBA) are important raw materials for organic synthesis 1, 2 and have a wide range of applications in the chemical industry 3, 4. Since ethanol and tert ‐butanol usually form three azeotropes with water in the refining process, i.e., ethanol‐water, tert ‐butanol‐water, and ethanol‐ tert ‐butanol‐water 5, they are difficult to separate by conventional distillation processes, so special distillation processes are used for their separation.…”

A multifunctional carrier for composite ZnFe2O4: a catalyst for improved one-step diethyl carbonate synthesis from CO2 and ethanol

“…15 Therefore, the catalytic conversion of CO 2 into diethyl carbonate not only reduces the emission of CO 2 , but also produces chemical substances with a wide range of uses, 16,17 which is in line with both economic and environmental benefits. 18,19 As shown in Table 1, the data reported by the state-of-the-art studies in this field were reproduced and listed from publishing year 2021 to 2016. From these recent references, it was found that ethanol conversion and DEC yield remained at a low level.…”

Synthesis of diethyl carbonate from ethanol and CO2 over ZrO2 catalysts

“…In batch reactors, KI/Molecular sieve was tested in the epoxide route and DEC yields of 25% were observed within 1 h of reaction (Anggerta et al 2019), the use of 2-cyanopyridine as water trap, also in a batch reactor, led to almost a 60% DEC yield over 3 h (Giram et al 2018). Continuous processes involving the application of porous membranes have also been developed (Arbeláez et al 2019;Wang et al 2017a, b) and productivities up to 47 mmol L −1 h −1 were achieved (Wang et al 2017a, b). Moreover, techniques of catalyst design were developed, with the use of evaporationimpregnation and deposition-precipitation in the synthesis (Leino et al 2018) and the use of the combination of KBr-KNO 3 with CeO 2 catalysts (Wang et al 2016).…”

“…The main drawback of this route is the thermodynamic limitation, being exothermic but not spontaneous under normal conditions (∆ r G o 298 K = + 35.85 kJ mol −1 ) (Leino et al 2011). Although, as described above, recent studies have been focusing on dislocating the thermodynamical equilibrium with water removal (Arbeláez et al 2019;Giram et al 2018;Wang et al 2017a, b), the development of more active catalysts is also critical to allow the reaction to be conducted at more favorable temperatures with higher selectivity.…”