600-14-6Relevant articles and documents
MECHANISM OF OXIDATION OF SOME ALIPHATIC KETONES BY N-BROMOSUCCINIMIDE IN ACIDIC MEDIA
Singh, Bharat,Pandey, Lalji,Sharma, J.,Pandey, S. M.
, p. 169 - 172 (1982)
Kinetics of the oxidation of methyl n-propyl ketone and methyl isobutyl ketone by N-bromosuccinimide (NBS) have been studied in perchloric acid media in presence of mercuric acetate.A zero order dependence to N-bromosuccinimide and a first order dependence to both ketones and hydrogen ion concentrations have been observed.Sodium perchlorate, mercuric acetate and succinimide additions have negligible effect while methanol addition has a positive effect on the reaction rate.A solvent isotope effect (k0D2O/K0H2O=2.3-2.7 and 2.4-2.8 for MeCOn.pr and MeCOi-Bu, respectively) has been observed at 35 deg.Kinetic investigations have revealedthat the order of reactivity is methyl n-propyl ketone>methyl isobutyl ketone.Various thermodinamic parameters have been computed and corresponding 1,2-diketones were found to be the products.A suitable mechanism in conformity with the above observations has been proposed.
An efficient and durable hierarchically porous KLA/TiPO catalyst for vapor phase condensation of lactic acid to 2,3-pentanedione
Zhang, Ju,Li, Xinli,Pang, Jun,Zou, Weixin,Tang, Congming,Dong, Lin
, p. 5972 - 5979 (2019)
Sustainable production of 2,3-pentanedione from bio-lactic acid via a vapor condensation reaction over KLA/TiPO (KLA: potassium lactate) was investigated in this work. A KNO3 precursor supported on the surface of TiPO was in situ converted to basic sites in a KLA/TiPO catalyst. KLA together with Ti4+(Lewis acidic site) make up the acid-base pairs in the KLA/TiPO catalyst, resulting in excellent activity for the condensation of lactic acid to 2,3-pentanedione. The loading amount of KNO3 was shown to have an important influence on the catalytic performance, since the acid-base properties of the catalysts were found to vary with the addition of KNO3. Reaction conditions such as lactic acid feed flow rate and lactic acid concentration were also discussed. Both lactic acid conversion and 2,3-pentanedione selectivity increased with elevated lactic acid feed flow rates, indicating the existence of an external diffusion resistance of the lactic acid reactant during the catalytic reactions. However, the lactic acid feed flow rate increased to 1.0 mL h?1 (corresponding to LA liquid hourly space velocity (LHSV) = 2.6 H?1), and the external diffusion resistance was efficiently eliminated. Enhancing the LA concentration improved the selectivity of 2,3-pentanedione, suggesting that the reaction order of the lactic acid molecule for lactic acid conversion to 2,3-pentanedione is higher than the other side reactions. Encouragingly, in retaining 30-45% of the lactic acid conversion, the condensation reaction with a 2,3-pentanedione selectivity of around 73% proceeded efficiently for at least 116 h on stream. The long-term stability of the present catalyst was found to be related to its hierarchical pores, which ameliorated the mass transfer effect of the reactant and product, except for the appropriate acid-base properties for lactic acid condensation to 2,3-pentanedione.
Potassium-Ion-Exchanged Zeolites for Sustainable Production of Acrylic Acid by Gas-Phase Dehydration of Lactic Acid
Yan, Bo,Tao, Li-Zhi,Mahmood, Azhar,Liang, Yu,Xu, Bo-Qing
, p. 538 - 550 (2017)
Development of high-performance solid acid catalysts for chemicals and materials production from bioresourced feedstock has become an important research topic in heterogeneous catalysis for renewable energy and green chemistry. We provide herein a comprehensive study on the catalytic performance of various K+-exchanged zeolites (KxNa1-xZ-y, x = 0.90-0.98) with similar molar K/Al ratios for acrylic acid (AA) production by gas-phase dehydration of lactic acid (LA) and discuss the effects of zeolite type (Z = ZSM-22, ZSM-35, MCM-22, ZSM-11, ZSM-5, ZSM-5/ZSM-11, and β) and SiO2/Al2O3 ratio (y). ZSM-5 and β are found more efficient than the other zeolites for this LA-to-AA reaction. Variation of y in the zeolite (β and ZSM-5) is shown to significantly affect the catalytic performance: not only higher AA selectivity and yield but also better catalytic stability is achieved by lowering y. A K0.97Na0.03ZSM-5-27 is then identified as the best-performing catalyst, offering very high AA selectivity (80-81 mol%) and yield (74-78 mol%) at 360 °C under high LA space velocity (WHSVLA = 2.1 h-1). This catalyst also shows a remarkable long-term stability, being capable to maintain a high AA selectivity (>70 mol%) and yield (>55 mol%) for longer than 80 h. Furthermore, an in situ calcination of the used catalyst with flowing air at 450 °C is shown to be efficient for complete catalyst regeneration. Correlating the catalyst performance with its surface acid-base property measured by NH3- and CO2-TPD clearly uncovers that balance between the surface acidity and basicity would be a key, besides Z and y of the zeolite, to the catalyst performance.
Selective conversion of lactic acid into acrylic acid over hydroxyapatite catalysts
Matsuura, Yumiko,Onda, Ayumu,Yanagisawa, Kazumichi
, p. 5 - 10 (2014)
Lactic acid conversion into acrylic acid was carried out over Ca-HAP catalysts at 623 K. Stoichiometric Ca-HAP catalyst gave a high acrylic acid yield of about 60 C-%. Furthermore, non-stoichiometric calcium deficient Ca-HAP catalysts containing the specific amounts of sodium ions, which were prepared under hydrothermal conditions, exhibited remarkably high acrylic acid yields of about 80 C-%. In contrast, non-stoichiometric Ca-HAP catalysts with vacancy sites and Ca-HAP catalysts with excess amounts of sodium species showed relatively low acrylic acid yields and high selectivities into acetaldehyde and 2,3-pentanedione.
Confined alkali metal ions in two-dimensional aluminum phosphate promoted activity for the condensation of lactic acid to 2,3-pentanedione
Dai, Yunsheng,Li, Xinli,Tang, Congming,Yang, Chenglong,Zhang, Ju
supporting information, p. 13806 - 13813 (2021/08/16)
The sustainable production of 2,3-pentanedione from bio-lactic acid was investigated over alkali metal ion-intercalated laminar aluminum phosphate. The confined alkali metal ion through the adjacent layers of aluminum phosphate offered excellent stability for the condensation of lactic acid to 2,3-pentanedione at least 80 h on stream, remaining constant at 55% conversion of lactic acid as well as around 80% of 2,3-pentanedione selectivity. The intercalated alkali metal ions can efficiently stabilize the enol intermediate, promoting the activity of lactic acid condensation. Besides, it can also prevent the occurrence of a layered stack of aluminum phosphate, providing an excellent mass transfer space for molecular diffusion, which is demonstrated by the calculation of the relation between molecular mean free paths for lactic acid and 2,3-pentanedione and the interlamellar spacing of aluminum phosphate. As a result, the alkali metal ion-intercalated laminar aluminum phosphate exhibited excellent performance for the condensation of lactic acid to 2,3-pentanedione at 270 °C, achieving 90% of lactic acid conversion and 80% of selectivity towards 2,3-pentanedione.
PREPARATION METHOD OF ACRYLIC ACID FROM LACTIDE BY USING ION EXCHANGE RESIN
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Paragraph 0051-0054; 0060; 0066; 0072; 0078; 0084, (2019/10/10)
The present invention relates to a method for manufacturing acrylic acid by dehydration of lactide derived from a biomass using a strongly acidic cation exchange resin. An object of the present invention is to provide the method for manufacturing acrylic acid, which is a high moisture absorbent raw material, in an environmentally friendly manner at a high yield and a high selectivity by using the strongly acidic cation exchange resin.COPYRIGHT KIPO 2019