Chlorination of glycerol with HCl to 1,3‐dichloro‐2‐propanol catalyzed by aliphatic carboxylic acids

Abstract

Glycerol oversupplied in biodiesel production can be used as a renewable raw material for producing high-valued chemicals, such as 1,3-dichloro-2-propanol (1,3-DCP), propanediol, acrolein, and acrylic acid. Catalytic chlorination of glycerol to 1,3-DCP is an alternative to propylene chlorination. The catalytic activities of various aliphatic carboxylic acid catalysts for the catalytic chlorination of glycerol with HCl to 1,3-DCP were investigated. When monocarboxylic acids, such as acetic, propanoic, butyric, and hexylic acids, were used as the catalysts, the monocarboxylic acids with the carbon numbers of 3 and 4 favored the glycerol chlorination to 1,3-DCP. When dicarboxylic acids, such as oxalic, malonic, succinic, and adipic acids, were used as the catalysts, the dicarboxylic acids with long carbon chain favored the glycerol chlorination to 1,3-DCP. The highest yield of 1,3-DCP of 88.6% was obtained over adipic acid catalyst after reacting at 110°C for 14 h. When hydroxylcarboxylic acids, such as citric, malic, and lactic acids, were used as the catalysts, the 1,3-DCP yields were approximately half of those over monocarboxylic and dicarboxylic acid catalysts with the same carbon number, respectively. The steric hindrance effect of carboxylic acids played an important role in glycerol chlorination to 1,3-DCP as compared with their acid strengths.

Selective Chlorination of Glycerol to 3-Chloro-1,2-Propanediol Catalyzed by Brønsted Acidic Ionic Liquids

“…The 1,3-DCP yield was less than 14% and a small amount of 2-MCPD and 2,3-DCP were formed. Furthermore, as compared with the case using carboxylic acid as the catalyst (Hou et al, 2015), the 3-MCPD yield increased by 10% over the Brønsted acidic ionic liquid catalysts, indicating that the Brønsted acidic ionic liquids favored the chlorination of glycerol to 3-MCPD, probably due to the steric hindrance effect of large molecules.…”

“…However, the production process is very complicated. In the production of dichloropropanol via the chlorination of glycerol, 3-MCPD is produced first as an intermediate product, which can be rapidly chlorinated to dichloropropanol over carboxylic acid catalysts Hou et al, 2015). Over heteropolyacid catalysts, 3-MCPD with a maximum selectivity of 42.3% was obtained, accompanied by the formation of dichloropropanol and other byproducts (Song et al, 2010).…”

Synthesis of epichlorohydrin from 1,3‐dichlorohydrin with solid catalysts using γ‐Al2O3 as carrier material

“…Besides, there are many problems with refining the main products and separating the catalysts from the reaction mixture . Compared with homogeneous catalysis, solid catalysis enables easier product separation, hence avoiding the production of large volumes of wastewater and increasing the cost efficiency, using less labor materials and financial resources …”

“…[8][9][10] Compared with homogeneous catalysis, solid catalysis enables easier product separation, hence avoiding the production of large volumes of wastewater and increasing the cost efficiency, using less labor materials and financial resources. [11][12][13][14] A solid base is a substance that can donate electron pairs or accept protons. 15 We divide it into the intrinsic type and load type according to structure.…”

Glycerol chlorination reaction mechanism

“…Furthermore, there are many works in the literature studying kinetic and mechanistic aspects of reaction of glycerol and HCl 13,16,17,19,20,29‐34 . Tesser and coworkers 19 have carried out several experiments using glycerol, gaseous HCl, and different organic acids as catalyst to obtain 1,3‐DCP.…”