Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesi...Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid （HPA） supported on acid-treated clay montmorillonite （K10）. 20% （w/w） dodecatungestophosphoric acid （DTPA） supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20% （w/w） DTPA/K10 for optimization of the activity.展开更多
In present work,liquid phase esterification of acetic acid with ethanol over dodecatungestophosphoric acid （DTPA） supported on K10 montmorillonite was systematically studied and optimization of process parameters wa...In present work,liquid phase esterification of acetic acid with ethanol over dodecatungestophosphoric acid （DTPA） supported on K10 montmorillonite was systematically studied and optimization of process parameters was carried out.The 20% m/m DTPA/K10 was found to be the optimum catalyst with 90% acetic acid conversion and 100% ethyl acetate selectivity.The study was also explored to see the feasibility of 20% m/m DTPA/K10 as a catalyst for the alkylation of acetic acid with other alcohols like methanol,iso-propanol and n-butanol.The 20% m/m DTPA/K10 has shown increased activity with the increase in carbon number,at the same alcohol reflux.The results are novel.展开更多
Fluoride excess in drinking water is noticed in many countries around the world and particularly in Senegal where, in addition to fluoride excess, high levels of salinity are also encountered. In order to reduce fluor...Fluoride excess in drinking water is noticed in many countries around the world and particularly in Senegal where, in addition to fluoride excess, high levels of salinity are also encountered. In order to reduce fluoride excess in drinking water in the groundnut basin of Senegal, two types of clays namely montmorillonite KSF and montmorillonite K10 as well were used as adsorbent materials. The results show that the pH which was initially alkaline becomes acidic varying from 2.80 to 6.80. The pseudo first-order kinetic model fit well with the adsorption experiments for KSF montmorillonite (<em>r</em><sup>2</sup> = 0.96), while for K10 clay the same model describe the experiments with slight differences (<em>r</em><sup>2 </sup>= 0.90). The KSF clay has a better fluoride adsorption capacity compared to that obtained with K10 clay due to the presence of a great level of calcium oxide in the montmorilonite KSF clay.展开更多
In this work, free tall oil fatty acids were epoxidized with in-situ generated peroxyacetic acid. Reaction kineticsof epoxidation was investigated by oxirane content and iodine value titrimetric determination, as well...In this work, free tall oil fatty acids were epoxidized with in-situ generated peroxyacetic acid. Reaction kineticsof epoxidation was investigated by oxirane content and iodine value titrimetric determination, as well as FTIRspectra analysis. A highly functional biobased polyol was synthesized by functionalizing epoxidized tall oilfatty acids with triethanolamine using Montmorillonite K10 as a catalyst. The obtained polyol was analyzed byFTIR and MALDI-TOF MS. The most common chemical and physical characteristics of obtained polyol weredetermined.展开更多
The catalysis of montmorillonite K10(MK10)for aryl O-glycosylation of glycosyl trichloroacetimidates was investigated.It was found that the catalyst MK10 is deactivated gradually in the recycle glycosylation.The fresh...The catalysis of montmorillonite K10(MK10)for aryl O-glycosylation of glycosyl trichloroacetimidates was investigated.It was found that the catalyst MK10 is deactivated gradually in the recycle glycosylation.The fresh and the deactivated catalysts were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Thermogravimetric analysis(TGA),and N_(2)adsorption-desorption.The results show that the eliminated trichloroacetamide molecule deposits on the MK10,which blocks and poisons the active sites,resulting in the deactivation of the catalyst.The regeneration of the deactivated MK10 by calcination was studied preliminarily.展开更多
基金S. Dharne thanks Director, NCL, Pune for permission to workas an M. E. (Chemical Engineering) project trainee
文摘Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid （HPA） supported on acid-treated clay montmorillonite （K10）. 20% （w/w） dodecatungestophosphoric acid （DTPA） supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20% （w/w） DTPA/K10 for optimization of the activity.
文摘In present work,liquid phase esterification of acetic acid with ethanol over dodecatungestophosphoric acid （DTPA） supported on K10 montmorillonite was systematically studied and optimization of process parameters was carried out.The 20% m/m DTPA/K10 was found to be the optimum catalyst with 90% acetic acid conversion and 100% ethyl acetate selectivity.The study was also explored to see the feasibility of 20% m/m DTPA/K10 as a catalyst for the alkylation of acetic acid with other alcohols like methanol,iso-propanol and n-butanol.The 20% m/m DTPA/K10 has shown increased activity with the increase in carbon number,at the same alcohol reflux.The results are novel.
文摘Fluoride excess in drinking water is noticed in many countries around the world and particularly in Senegal where, in addition to fluoride excess, high levels of salinity are also encountered. In order to reduce fluoride excess in drinking water in the groundnut basin of Senegal, two types of clays namely montmorillonite KSF and montmorillonite K10 as well were used as adsorbent materials. The results show that the pH which was initially alkaline becomes acidic varying from 2.80 to 6.80. The pseudo first-order kinetic model fit well with the adsorption experiments for KSF montmorillonite (<em>r</em><sup>2</sup> = 0.96), while for K10 clay the same model describe the experiments with slight differences (<em>r</em><sup>2 </sup>= 0.90). The KSF clay has a better fluoride adsorption capacity compared to that obtained with K10 clay due to the presence of a great level of calcium oxide in the montmorilonite KSF clay.
文摘In this work, free tall oil fatty acids were epoxidized with in-situ generated peroxyacetic acid. Reaction kineticsof epoxidation was investigated by oxirane content and iodine value titrimetric determination, as well as FTIRspectra analysis. A highly functional biobased polyol was synthesized by functionalizing epoxidized tall oilfatty acids with triethanolamine using Montmorillonite K10 as a catalyst. The obtained polyol was analyzed byFTIR and MALDI-TOF MS. The most common chemical and physical characteristics of obtained polyol weredetermined.
基金The financial supports from the National Natural Science Foundation of China(Grant Nos.20672027 and 20972039)the Natural Science Foundation of Hebei(B2008000588)。
文摘The catalysis of montmorillonite K10(MK10)for aryl O-glycosylation of glycosyl trichloroacetimidates was investigated.It was found that the catalyst MK10 is deactivated gradually in the recycle glycosylation.The fresh and the deactivated catalysts were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Thermogravimetric analysis(TGA),and N_(2)adsorption-desorption.The results show that the eliminated trichloroacetamide molecule deposits on the MK10,which blocks and poisons the active sites,resulting in the deactivation of the catalyst.The regeneration of the deactivated MK10 by calcination was studied preliminarily.
