The influence of water-miscible alcohols (methanol, 1-propanol, 2-propanol, and t-butyl alcohol) on the isomerization of glucose to fructose and mannose was investigated under subcritical aqueous conditions (180-200 °C). Primary and secondary alcohols promoted the conversion and isomerization of glucose to afford fructose and mannose with high and low selectivity, respectively. On the other han...

The subcritical fluid extraction of lovastatin from tablet powder mixtures prepared in this laboratory and MEVACOR tablets is successfully demonstrated. Methanol modifier percentage, additive type (acidic, basic, or neutral), and additive concentration on the extraction efficiency are examined. The extraction recoveries of lovastatin from MEVACOR tablets are shown to be highly dependent on meth...

The aim of this study is to explore the capability of subcritical methanol to reduce the acidity of naphthenic acids and to determine reaction kinetics for large-scale reactor design.The experiments were carried out in a 25 mL autoclave reactor (China) at temperatures of 70-120oC, Methanol Partial Pressures (MPPs) of 0.1-1.5 MPa, and reaction times of 0-60 min. The total...

The aim of this study is to explore the capability of subcritical methanol to reduce the acidity of naphthenic acids and to determine reaction kinetics for large-scale reactor design.The experiments were carried out in a 25 mL autoclave reactor (China) at temperatures of 70-120oC, Methanol Partial Pressures (MPPs) of 0.1-1.5 MPa, and reaction times of 0-60 min. The total...

Most previous studies reported in literature on biodiesel production from sludge were performed by acid catalyzed transesterification that required long reaction time (about 24h) and high methanol loading. The objective of this study was to investigate the in situ transesterification of sludge in subcritical mixture of methanol and acetic acid. At 250°C and a solvent (85% methanol and 15% aceti...

Esterification of several carboxylic acids with supercritical alcohols such as 1-propanol, 1butanol, 1-octanol, isoamylalcohol, ethanol, methanol, and subcritical benzyl alcohol without using any catalyst was studied. A variety of esters were synthesized very effectively using supercritical alcohols as solvent and reagent. Moderate to excellent yields were obtained depending on the nature of th...

Study presents that supercritical methanol has the ability to convert oils/fats consisting of triglycerides and free fatty acids (FFAs) into fatty acid methyl esters through transesterification and methyl esterification, respectively, without any catalyst. This one-step method (Saka process) is simpler process realizing shorter reaction time and higher yield of methyl esters than those of the c...

Copper and nickel mixed catalysts obtained by calcination of iron aluminium hydrotalcites (layered double hydroxides, LDH) have been tested in the conversion a lignin model dimer subcritical methanol. Phase distribution textural properties were characterized X-ray diffraction Rietveld analysis N2 physisorption. The presence copper was critical for effective hydrogenation, both direct hydrogen t...