Catalysts for vapor-phase dehydration of ethylene glycol and their application to pyruvic acid synthesis

High-Performance Vapor-Phase Selective Oxidation of Ethyl Lactate to Ethyl Pyruvate over SiO2 Supported PMoVNb Oxides

“…Pyruvate and its esters are important chemicals widely used in food, spice, cosmetics, pharmaceutical and other industries [2][3][4]. Currently, pyruvate and its esters are still produced mainly via the energy-intensive pyrolysis of tartaric acid with KHSO 4 as a dehydrating agent [5,6]. Unfortunately, this process obtains a yield of only 50-54% but obviously negative environmental effect due to the use of numerous dehydrating agents.…”

“…This is a green and atom-economical reaction route which has received extensive attention from the scientific and industrial circles. This highly atom-efficient catalytic oxidative dehydrogenation process includes liquid and vapor phase strategies [5,[10][11][12][13][14].…”

Highly Efficient Oxidation of Ethyl Lactate to Ethyl Pyruvate Catalyzed by TS-1 Under Mild Conditions

“…Pyruvic acid and its esters (pyruvate) are important raw materials and chemical intermediates which are widely applied in food, plastic, pharmaceutical, and pesticidal industries. − They can also be used as the precursors in the synthesis of bioactive substances. , Currently, the commercial production of pyruvate is realized by the dehydrative decarboxylation of tartaric acid. Excess KHSO 4 as a dehydrating agent is required in this process, leading to low atom efficiency and environmental pollution . Pyruvate can also be produced by microbial fermentation of carbohydrates. − However, precise regulation of the reaction conditions including pH value, temperature, and so on, low space–time yield, and high cost of product separation and purification limit the industrialization of this method.…”

.alpha.-Te2MoO7 as an Active Species in the Vapor-Phase Selective Oxidation of Ethyl Lactate to Pyruvate over TeO2-MoO3 Catalysts

“…Pyruvic acid is the simplest homologue of a-keto acids, which were extensively reviewed (Cooper et al, 1983), covering 19 general methods for their synthesis. Some of the routes are elegantly designed for laboratory procedure in organic synthesis, but the applications of catalytic processes are of more recent vintage (Sugiyama et al, 1991(Sugiyama et al, , 1992(Sugiyama et al, , 1993; Tsujino et al, 1992;Hayashi et al, 1993a-c).…”

“…An established laboratory procedure (Howard and Fraser, 1945) for pyruvic acid synthesis is the dehydrative decarboxylation of tartaric acid in the presence of an excess of powdered potassium hydrogen sulfate (KHSO4). Although the unique dehydrating agent KHSO4 melts at a low temperature of 197 °C, it was successfully adapted for vapor-phase flow operations as a silica-supported pyrosulfate catalyst (K2S2C>7/Si02) to obtain ethyl pyruvate continuously from the tartrate in a rather good yield of 60% at 300 °C (Sugiyama et al, 1991(Sugiyama et al, , 1992). An alternative approach to pyruvic acid, bypassing the expensive tartrate, has been made by the liquid-phase oxidation of sodium lactate (eq 1, R = Na) on lead-modified palladium-on-carbon and related cata-…”