scholarly journals Synthesis of propylene carbonate from urea and 1,2-propylene glycol over metal carbonates

2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.

2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.


2013 ◽  
Vol 781-784 ◽  
pp. 276-279
Author(s):  
Yu Hang Zhao ◽  
Li Cui ◽  
Da Zhi Wang ◽  
Tong Kuan Xu ◽  
Yong Peng Li

Butanone 1,2-propanediol ketal was synthesized by butanone and 1,2-propanediol as raw materials and sulfamic acid as catalyst. The effects of the mole ratio of raw materials agent, the dosage of the water-carrying agent and catalyst, reaction time on the product yield were discussed separately. Experimental results showed that sulfamic acid was a suitable catalyst for synthesizing of butanone 1,2-propanediol ketal. And the optimal reaction conditions are as follows: the mole ratio of butanone to 1,2-propanediol is 1:1.5, the amount of the catalyst is 2.2%, the water-carrying agent is 25ml, the reaction temperature is 358-378K and reaction time 3h. In this condition, the yield of production could reach 93.8%.


2012 ◽  
Vol 550-553 ◽  
pp. 400-403 ◽  
Author(s):  
Xue Nan Sun ◽  
Li Cui ◽  
Tong Kuan Xu ◽  
Da Zhi Wang

Benzaldehyde 1, 2-propanediol acetal was synthesized from benzaldehyde and 1, 2-propanediol in the presence of ionic liquid [HMIM]HSO4. The effect of the amount of catalyst, reaction time, reaction temperature, and the molar ratio of raw materials agent on the product yield was investigated respectively. Experimental results demonstrate that ionic liquid [HMIM]HSO4is a good catalyst for preparation of benzaldehyde 1, 2-propanediol acetal. Results showed the optimal reaction conditions are as follows: the mole ratio of benzaldehyde to 1, 2-propanediol is 1:1.3, the amount of catalyst is 3.0g, the reaction temperature is 343K, and the reaction time is 4h. The achieved yield of acetal is 78. 7%.


Author(s):  
Hao Peng ◽  
Liu Yang ◽  
Ya Chen ◽  
Jing Guo

This paper focused on the oxidative leaching process of vanadium from vanadium-chromium reducing residue in alkaline medium with MnO2. The effect of experimental parameters including reaction time, reaction temperature, dosage of MnO2, dosage of NaOH, and liquid-to-solid ratio on the leaching efficiency of vanadium had been studied. The results indicated that MnO2 was an efficient oxidant for leaching out of vanadium. The leaching efficiency of vanadium was up to 97.25% under optimal reaction conditions: reaction temperature of 90 ℃, reaction time of 60 min, dosage of MnO2 at 50 wt.%, concentration of NaOH at 30 wt.% and liquid-to-solid at 5:1 mL/g.


2014 ◽  
Vol 1033-1034 ◽  
pp. 30-33
Author(s):  
Xiang Wen Kong ◽  
Huan Wang ◽  
Han Wang ◽  
Li Li Ren ◽  
Zhao Jing Li

Amyl ferulate was synthesized by direct esterification with using sodium bisulfate supported by silica as a catalyst, ferulic acid and n-pentanol as raw materials. The influences of some factors on the synthetic process were studied. The optimal reaction conditions based upon 0.2 mol of ferulic acid were chosen that the molar ratio of n-pentanol and ferulic acid was 2 : 1, the mass ratio of catalyst to reactants was 6%, refluxing reaction time was 3 hours. The yield of the product reached 97% under the above conditions. The structure of the product was characterized by IR, 1H NMR and MS spectrum. The catalyst could be recycled and used for many times.


2011 ◽  
Vol 233-235 ◽  
pp. 180-183
Author(s):  
Feng Lan Xing ◽  
Bo Ming ◽  
Ming Zhao

O-cationic Chitosan was prepared by self-made cationic ether agent 2,3-epoxypropyl trimethyl ammonium chloride(GTA) and chitosan. In this process, the effects of reaction solvent, reaction temperature, reaction time, amount of KOH and GTA on the substitution of O-cationic chitosan were studiedand the optimal reaction conditions were investigated. The optimal reaction conditions were as follows: reaction solvent Isopropanol, reaction time 30 h,reaction temperature 85 °C, KOH 3 mL(40 %) and the ratio of chitosan to GTA is 1:1.5.The degree of cationic is 55.36 %.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Guobi Li ◽  
Wenyi Su ◽  
Chunlin Ni

A new ruthenium complex, Ru(bpbp)(pbb)Cl, based on 2,6-bis(1-(phenyl)-1H-benzo[d]imidazol-2-yl)pyridine (bpbp) and 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)benzoate (pbb) was synthesized. The complex Ru(bpbp)(pbb)Cl could catalytically oxidize 1-(1H-benzo[d]imidazol-2-yl)ethanol to 1-(1H-benzo[d]imidazol-2-yl)ethanone with H2O2 as oxidant. Influence of temperature and catalyst amount on the oxidation reaction was evaluated. The reaction optimal conditions are as follows: molar ratio of catalyst to substrate to H2O2 is 1 : 1000 : 3000, the proper reaction temperature is 50°C and reaction time lasts 5 h, and the isolated yield of 1-(1H-benzo[d]imidazol-2-yl)ethanol to 1-(1H-benzo[d]imidazol-2-yl)ethanone under the optimal reaction conditions is 57%.


2010 ◽  
Vol 1279 ◽  
Author(s):  
Xianmei Xie ◽  
Lian Duan ◽  
Zhenghuang Wu ◽  
Lina Wang ◽  
Kai Yan ◽  
...  

AbstractCuFe-Hydrotalcite-Like Compounds (CuFe-HTLcs) were synthesized by coprecipitation with Cu(NO3)2·6H2O, Fe(NO3)3·9H2O, NaOH and Na2CO3 solution. The sample with Cu2+ / Fe3+ = 2 was of the highest crystalline characterized by XRD and particle size distribution. The synthesis of propylene carbonate from 1,2-propanediol (PG) and urea was performed to evaluate the catalytic activities of the CuFe-HTLcs. The effects of reaction time, temperature, dosage of catalyst on the synthesis of propylene carbonate were fully discussed. The optimal reaction conditions were determined by using orthogonal test design: reaction temperature 170 °C, dosage of catalyst 0.2 g, and molar ratio of PG to urea 2:1, reaction time 3 h. Under the optimal conditions, the conversion of urea nearly reached 100 %, and the selectivity of propylene carbonate was up to 90.4%.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2562 ◽  
Author(s):  
Chia-Hung Su ◽  
Hoang Nguyen ◽  
Uyen Pham ◽  
My Nguyen ◽  
Horng-Yi Juan

This study investigated the optimal reaction conditions for biodiesel production from soursop (Annona muricata) seeds. A high oil yield of 29.6% (w/w) could be obtained from soursop seeds. Oil extracted from soursop seeds was then converted into biodiesel through two-step transesterification process. A highest biodiesel yield of 97.02% was achieved under optimal acid-catalyzed esterification conditions (temperature: 65 °C, 1% H2SO4, reaction time: 90 min, and a methanol:oil molar ratio: 10:1) and optimal alkali-catalyzed transesterification conditions (temperature: 65 °C, reaction time: 30 min, 0.6% NaOH, and a methanol:oil molar ratio: 8:1). The properties of soursop biodiesel were determined and most were found to meet the European standard EN 14214 and American Society for Testing and Materials standard D6751. This study suggests that soursop seed oil is a promising biodiesel feedstock and that soursop biodiesel is a viable alternative to petrodiesel.


2012 ◽  
Vol 468-471 ◽  
pp. 1371-1374
Author(s):  
Ke Nian Wei ◽  
Bin Zhou ◽  
Jiang Quan Ma ◽  
Yan Wang

HPW/C catalysts were prepared using impregnation method. The physical chemistry properties of the catalysts were characterized employing XRD and NH3-TPD.The effects of HPW loading, catalyst amount and reaction time on the catalyst performances were investigated. The results more acid content and active center contribute to the reaction performance. Under the optimal reaction conditions of 0.8g 29%(w) HPW/C as the catalyst, n(adipic acid): n(ethanol):n(toluene)=1:6:1,5h,the etherification rate was 97.3%.


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