Continuous Gas-Phase Synthesis of 1-Ethyl Chloride from Ethyl Alcohol and Hydrochloric Acid Over Al₂O₃-Based Catalysts: The “Green” Route

Abstract

The synthesis of 1-ethyl chloride in the gas-phase mixture of ethanol and hydrochloric acid over ZnCl 2 /Al 2 O 3 catalysts was studied in a continuous reactor using both commercial and tailor-made supports. The catalytic materials were characterized by the means of structural (XPS, TEM, XRD, and BET) and catalytic activity (selectivity and conversion) measurements. The reaction parameters such as temperature, pressure, and feedstock flow rates were optimized for the conversion of ethanol to ethyl chloride. The new tailor-made highly porous Al 2 O 3 -based catalyst outperformed its commercial counterpart by exhibiting high conversion and selectivity (∼98%) at the temperature of 325°C. Long-term stability tests (∼240 h) confirmed the excellent durability of the tailor-made alumina catalysts. The process demonstrated here poses an efficient and economic "green" largescale on-site synthesis of this industrially important reactant in industry, where bioethanol is produced and 1-ethyl chloride is necessary, e.g., for ethylation of cellulose and synthetic polymer products. On-site in situ production of ethyl chloride avoids the problems associated with the transportation and storage of toxic and flammable 1-ethyl chloride.

Kinetics of ethanol hydrochlorination over γ-Al2O3 in a microstructured reactor

“…The activation energies and preexponential factors for the ethyl chloride and diethyl ether formation were determined with low errors (o5% energy of ethyl chloride formation is 79 kJ/mol which is in agreement with the results of Bukhanko et al (2013). The parameters for the HCl adsorption and acetaldehyde formation are less precise with an error of 6.7 and 12% respectively.…”

“…So far only one kinetic study on ethanol hydrochlorination has been published (Bukhanko et al, 2013). Neat and ZnCl 2 modified aluminas have been tested and activation energies for the hydrochlorination reaction of ethanol have been reported.…”

Reversible formation of alcohol solvates and their potential use for heat storage

“…For alkyl chloride formation in our system different pathways could be assumed. It has been reported that gas phase reaction of EtOH and HCl with formation of H 2 O over ZnCl 2 /Al 2 O 3 as a catalyst, is a suitable method for ethyl chloride preparation [80]. According to a possible explanation, the starting material ( A direct interaction between the ligands (i.e., Cland alcohol) in the coordination sphere of the Mg 2?…”

Gas phase synthesis of isopropyl chloride from isopropanol and HCl over alumina and flexible 3-D carbon foam supported catalysts

“…Two main routes are widely used upon isopropyl chloride production -hydrochlorination of propylene over different catalysts (such as alumina, FeCl3, hydrochlorinated alumina, tellurium compounds) and hydrochlorination of isopropanol over zinc chloride or aluminosilicate catalysts [7][8][9][10][11][12][13][14][15][16]. Hydrochlorination of alkenes and primary alcohols to synthesise corresponding primary alkyl halides is more preferable than chlorination because of environmental reasons [17][18][19][20][21][22][23]. Esterification of primary alcohols (methanol, ethanol) over highly porous and non-toxic alumina catalysts was found to be the most environmentally friendly, modern, and efficient route [20][21][22][23].…”

“…Hydrochlorination of alkenes and primary alcohols to synthesise corresponding primary alkyl halides is more preferable than chlorination because of environmental reasons [17][18][19][20][21][22][23]. Esterification of primary alcohols (methanol, ethanol) over highly porous and non-toxic alumina catalysts was found to be the most environmentally friendly, modern, and efficient route [20][21][22][23]. This method can also be considered as "green" when utilising bio-alcohols (produced by biomass fermentation) as feedstock [24][25][26][27].…”