Catalysts and Supports for Conversion of Lactic Acid to Acrylic Acid and 2,3-Pentanedione

Abstract

The catalytic conversion of lactic acid over various sodium salt catalysts and support materials has been carried out to identify potential catalyst/support combinations for 2,3-pentanedione and acrylic acid production. Low surface area, pure silica is the best support for suppressing undesirable side reactions to acetaldehyde and propanoic acid, which are favored over high surface area (microporous) or surface acidic materials. The best catalysts for 2,3-pentanedione and acrylic acid formation are the sodium salts of group IV and group V oxides, with sodium arsenate giving a 2,3-pentanedione yield of 25% and combined selectivity to acrylic acid and 2,3-pentanedione of 83% at 300 °C and 0.5 MPa total pressure.

Catalytic dehydration of lactic acid to acrylic acid over sulfate catalysts

“…In the dehydration process, lactic acid can be reduced by reductive materials to form propanoic acid. What needs to be emphasized is that the reductive materials include activated carbon support (Gunter et al, 1995), formed coke on catalysts surfaces or hydrogen originated during dehydration process. In Table 5, molar yield of acrylic acid from 26 wt.% lactic acid is only 0.7% at 400…”

“…Furthermore, as the application of anaerobic lacto-bacteria (Bai et al, 2003), energy saving is achieved in this process. Lactic acid is capable to produce various chemicals such as acrylic acid, propanoic acid, acetaldehyde, 2,3-pentanedione (Gunter et al, 1994(Gunter et al, , 1995Waldley et al, 1997;Varadarajan and Miller, 1999), as well as biodegradable poly lactic acid. All the products from lactic acid are industrial chemicals, and the products can be separated by matured industrial process.…”

Catalytic conversion of lactic acid into propylene glycol over various metals supported on silica

“…Lactic acid has been known as one of the most reactive species because it has both hydroxyl and carboxy functional groups. It can be converted into a variety of chemicals through polymerization [4], condensation [5][6][7], dehydration [8], esterification [9,10], and oxidation [11].…”

Highly efficient and robust Mg0.388Al2.408O4 catalyst for gas-phase decarbonylation of lactic acid to acetaldehyde

“…Carbon monoxide is also used to synthesize propionaldehyde and other aldehydes through hydroformylation reaction of ethylene and other alkenes [14][15][16][17]. As a platform molecule, LA is utilized to produce many value added chemicals such as acrylic acid [18][19][20][21][22][23], acetaldehyde [8], 2,3-pentanedione [24,25], propionic acid [26], pyruvic acid [27] and polylactic acid [28]. Except for corn starch, rich and inexpensive biomass materials such as cellulose [29], sugars [30], and sorbitol [31] have also been used to produce LA.…”