Production of Lactic Acid From Glycerol by Applying an Alkaline Hydrothermal Process Using Homogeneous Catalysts and High Glycerol Concentration

Abstract

-The production of lactic acid from glycerol by means of the alkaline hydrothermal process was evaluated using high concentrations of glycerol. The operating conditions that influence the hydrothermal process were studied. Temperature (250 -280 °C), catalyst to glycerol molar ratio (0.05 to 0.15), and water to glycerol volumetric ratio (0.8 to 1.5) were evaluated, as well as the use of NaOH and KOH as catalysts. A concentration of lactic acid of 122 g/L was obtained at 260 °C, 0.04 NaOH to glycerol molar ratio, 1.0 water to glycerol volumetric ratio and 3 h of reaction using crude glycerol as raw material. The results showed higher lactic acid concentration and productivity than the fermentative process and the hydrothermal process carried out using low initial glycerol concentration.

Mechanism Analysis and Kinetic Modelling of Cu NPs Catalysed Glycerol Conversion into Lactic Acid

“…When PG was used as a substrate, the LA formation was observed only using a tandem catalytic system. According to modern ideas about the possible pathway of the process [25,32,33], the reaction of LA formation consists of several consecutive steps. On the first step, glyceraldehyde and dihydroxyacetone, which is tautomeric pair, are formed by the removal of hydrogen from glycerol (Figure 1).…”

Polar Aromatic Compounds in Soot from Premixed Flames of Kerosene, Synthetic Paraffinic Kerosene, and Kerosene–Synthetic Biofuels

“…That is, under the proper conditions even the most non-polar solvents such as n-hexane can extract polar-AHs. Thus, Viana et al (2003) 42 demonstrated that extraction by supercritical CO 2 and Soxhlet extraction with n-hexane or dichloromethane (CH 2 Cl 2 ) were comparably effective in the case of lapachol (a very polar aromatic compound: a hydroxy-quinone) from Tabebuia avellanedae wood. Therefore, fractioning procedures are mandatory after extraction in order to isolate the target fractions.…”

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“…Therefore, the investigations mentioned above would be helpful to deeply understand the formation mechanism of WTBs with a compression molding. Besides, a use of PLLA would be a promising application of glycerol as a by-product of the biofuel because a production process of lactic acid from glycerol has been well established [20]. In this study, we aimed the chemical modification of WTBs using cellulose-g-PLLA according to the previous method [18].…”