scholarly journals A facile and effective method for preparation of 2.5-furandicarboxylic acid via hydrogen peroxide direct oxidation of 5-hydroxymethylfurfural

2017 ◽  
Vol 19 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Shuang Zhang ◽  
Long Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Oxidation Mechanism ◽  
Molar Ratio ◽  
Alkaline Condition ◽  
Optimal Parameters ◽  
Direct Oxidation ◽  
Reaction Parameters ◽  
Alkaline Conditions ◽  
Furandicarboxylic Acid

Abstract In this paper, 2,5-furandicarboxylic acid (FDCA) was efficiently prepared by the direct oxidation of 5-hydroxymethylfurfural (5-HMF) using hydrogen peroxide (H2O2) in alkaline conditions without any catalysts. The effects of reaction parameters on the process were systematically investigated and the optimal parameters were obtained as follows: molar ratio of 5-HMF:KOH:H2O2 was 1:4:8, reaction temperature and reaction time were determined as 70°C and 15 minutes, respectively. Under these conditions, the yield of FDCA was 55.6% and the purity of FDCA could reach 99%. Moreover, we have speculated the detailed oxidation mechanism of 5-HMF assisted by hydrogen peroxide in alkaline condition to synthesize FDCA.

scholarly journals The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Allyl Alcohol ◽  
Water Solution ◽  
Reaction Medium ◽  
Diglycidyl Ether ◽  
Molar Ratio ◽  
Water Medium ◽  
Catalyst Content ◽  
Allyl Alcohol Epoxidation

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

Heterogeneous Microwave Irradiation Biodiesel Processing of Jatropha Oil

2014 ◽  
Vol 554 ◽  
pp. 500-504 ◽  
Author(s):  
Farid Nasir Ani ◽  
Ahmed Bakheit Elhameed
Keyword(s):  
Reaction Time ◽  
Methyl Ester ◽  
Microwave Irradiation ◽  
Calcium Oxide ◽  
Production Cost ◽  
Catalyst Concentration ◽  
Molar Ratio ◽  
Biodiesel Fuel ◽  
Jatropha Oil ◽  
Reaction Parameters

This paper investigated the three critical reaction parameters including catalyst concentration, microwave exit power and reaction time for the transesterification process of jatropha curcas oil using microwave irradiation. The work is an attempt to reduce the production cost of biodiesel. Similar quantities of methanol to oil molar ratio 6:1 and calcium oxide as a heterogeneous catalyst were used. The results showed that the best yield percentage 96% was obtained using 300W microwave exit power, 8 %wt CaO and 7 min. The methyl ester FAME obtained was within the standard of biodiesel fuel.

Oxidation of Benzaldehyde to Benzoic Acid with Aqueous Hydrogen Peroxide over Dodecatungstophosphoric Acid

2013 ◽  
Vol 781-784 ◽  
pp. 219-222
Author(s):  
Qiu Ying Huang ◽  
Bei Bei Dong ◽  
Xiu Cheng Zheng
Keyword(s):  
Hydrogen Peroxide ◽  
Benzoic Acid ◽  
Catalytic Reaction ◽  
Type Structure ◽  
Optimal Parameters ◽  
Reaction Parameters ◽  
Aqueous Hydrogen Peroxide ◽  
Reaction Conditions ◽  
Prepared Sample ◽  
Keggin Type

Dodecatungstophosphoric acid was synthesized and used as catalyst for oxidation of benzaldehyde to benzoic acid with aqueous hydrogen peroxide. The effect of various catalytic reaction parameters including time, temperatures, and the amount of catalyst on the yield of benzoic acid was investigated in details. The results indicated that the as-prepared sample was in the keggin-type structure and the optimal parameters under the reaction conditions were as follows: 0.5 g of catalyst, reacted at 80 C for 5 h.

Optimization of a Ti-MWW Catalysed Phenol Hydroxylation Process

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Agnieszka Wróblewska
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Organic Compounds ◽  
Design Method ◽  
Uniform Design ◽  
Molar Ratio ◽  
Phenol Hydroxylation ◽  
Statistical Experimental Design ◽  
Experimental Design Method ◽  
Good Substitute

AbstractsAs a result of phenol hydroxylation, two useful products can be received: hydroquinone and pyrocatechol. In this work the hydroxylation of phenol with hydrogen peroxide over the Ti-MWW catalyst has been studied. Optimization studies were performed by application of a statistical experimental design method utilizing a rotatable-uniform design. The influence of five parameters on the course of this process was examined: temperature (120-150°C), molar ratio of phenol/hydrogen peroxide (0.5-1.5), acetonitrile - solvent content (20- 50 wt%), catalyst - Ti-MWW content (8-18 wt%) and reaction time (60-120 min). The process description was based on four response functions: the conversion of phenol to organic compounds, the yield of pyrocatechol, the yield of hydroquinone and the conversion of phenol to tars. The most favourable parameters for the process of phenol hydroxylation were as follows: temperature 147-150°C, molar ratio of phenol/hydrogen peroxide 0.5-0.6, acetonitrile content 21-24 wt%, Ti-MWW content 10.3-10.6, reaction time 221-236 min. In summary, these the most favourable parameters allow one to obtain pyrocatechol with the yield of 18 mol%, hydroquinone with the yield of 20 mol%, at the conversion of phenol to organic compounds 38 mol% in relatively mild and safe conditions. These results also showed that Ti-MWWcatalyst can be a good substitute for TS-1 catalyst.

scholarly journals Epoxidation of allyl-glycidyl ether with hydrogen peroxide over Ti-SBA-15 catalyst and in methanol medium

2016 ◽  
Vol 18 (4) ◽  
pp. 9-14 ◽  
Author(s):  
Marika Walasek ◽  
Agnieszka Wróblewska
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Glycidyl Ether ◽  
Diglycidyl Ether ◽  
Methanol Concentration ◽  
Molar Ratio ◽  
Oxidizing Agent ◽  
Aqueous Hydrogen Peroxide ◽  
Allyl Glycidyl Ether ◽  
Catalyst Content

Abstract This work presents the studies on the epoxidation of allyl-glycidyl ether (AGE) over the Ti-SBA-15 catalyst. In these studies an aqueous hydrogen peroxide was used as an oxidizing agent and as a solvent methanol was applied. The studies on the influence the following parameters: temperature (20–80°C), molar ratio of AGE/H2O2 (1:1.5–5:1), methanol concentration (10–90 wt%), catalyst content (1–9 wt%) and reaction time (15–240 min.) were carried out and the most favourable values of these parameters were chosen (temperature 80°C, molar ratio of AGE/H2O2 = 5:1, methanol concentration 30 wt%, catalyst content 3 wt% and the reaction time 240 min.). At these conditions the functions describing the process reached the following values: the selectivity of diglycidyl ether (DGE) 9.2 mol%, the conversion of AGE 13.9 mol% and the efficiency of H2O2 conversion 89.9 mol%.

Stabilization of iron-catalysed hydrogen peroxide decomposition by magnesium

1990 ◽  
Vol 68 (9) ◽  
pp. 1537-1543 ◽  
Author(s):  
John Abbot ◽  
Douglas G. Brown
Keyword(s):  
Hydrogen Peroxide ◽  
Alternative Explanation ◽  
Catalytic Decomposition ◽  
Molar Ratio ◽  
Hydrogen Peroxide Decomposition ◽  
Complex Species ◽  
Hydrolysis Products ◽  
Peroxide Decomposition ◽  
Alkaline Conditions ◽  
Decomposition Experiments

Catalytic decomposition of alkaline hydrogen peroxide by iron can be retarded by introduction of magnesium ions. This effect has been studied to evaluate the possibility of stabilization via formation of an iron–magnesium complex species. Under alkaline conditions, magnesium reacts with initial hydrolysis products of Fe3+ to produce a colourless complex species, in which the metal centres are probably linked through oxy or hydroxy bridges. This species is produced when the Mg:Fe molar ratio exceeds 6:1, and this ratio is also significant when magnesium is introduced during peroxide decomposition experiments. The evidence suggests that complex formation is an important factor in producing stabilization, and cannot be disregarded in favour of an alternative explanation where superoxide radicals combine with Mg2+ to produce magnesium dioxide. Keywords: hydrogen peroxide, kinetics, iron, magnesium, stabilization.

The Process of Phenol Hydroxylation in the Water Solution and over the Ti-MWW Catalyst

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Agnieszka Wróblewska
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Raw Materials ◽  
Water Solution ◽  
Uniform Design ◽  
Mathematical Optimization ◽  
Cost Effective ◽  
Molar Ratio ◽  
Phenol Hydroxylation ◽  
Technological Parameters

Abstract This work presents the studies on the optimization of the process of phenol hydroxylation over the Ti-MWW catalyst. The medium of the reaction was only water introduced into the rector with the 30 wt% hydrogen peroxide (oxidizing agent) and formed during the reaction from the hydrogen peroxide. For the mathematical optimization the rotatable-uniform design was used. The main investigated technological parameters were: the temperature, the molar ratio of phenol/hydrogen peroxide, the catalyst content and the reaction time. The course of the main functions describing the process were presented in the form of layer drawings. The analysis of the layer drawings allowed to establish the most beneficial parameters for this process. Studies have shown that in water solution it is best to conduct phenol hydroxylation process at: the temperature of 93-100oC, phenol/hydrogen peroxide molar ratio 0.9-1, catalyst concentration 3-3.5 wt% and during the reaction time of 55-60 minutes. Under these conditions, it is possible to achieve phenol conversion of 85 mol%, selectivity of transformation to organic compounds in relation to phenol consumed 50 mol% and the yield of hydroquinone about 19 mol%. The phenol hydroxylation method, presented in this article, is a preferred alternative to conventional solutions, as it is more environmentally and cost-effective, taking into account consumption of raw materials and energy.

scholarly journals Turritella terebra Shell Synthesized Calcium Oxide Catalyst for Biodiesel Production from Chicken Fat

2020 ◽  
Vol 997 ◽  
pp. 93-101
Author(s):  
Mohd Nurfirdaus Mohiddin ◽  
A.A. Saleh ◽  
Amarnadh N.R. Reddy ◽  
Sinin Hamdan
Keyword(s):  
Reaction Time ◽  
Oxide Catalyst ◽  
Catalyst Concentration ◽  
Catalytic Performance ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Reaction Parameters ◽  
Renewable Source ◽  
Chicken Fat

Heterogeneous catalyst has been viewed as a promising catalyst for biodiesel production. This study employed Turritella terebra (TT) shell as a source for synthesizing heterogeneous CaO catalyst for biodiesel production via transesterification by utilizing chicken fat as a feedstock. The TT shell CaO catalyst was characterized and its catalytic performance was studied. The spectrographic methods that include FTIR, SEM, PSA, and BET-BJH were employed for characterization of the synthesized CaO. The TT shell CaO catalyst optimally produced chicken fat biodiesel (CFB) with reaction parameters at catalyst concentration of 4 wt%, chicken fat to methanol molar ratio of 1:12, reaction temperature of 60°C, and reaction time of 90 min. The optimal yield was 94.03% and the TT shell CaO catalyst still yield 79.19% of CFB on the fifth cycle of reaction. This study has implied that TT shell is a feasible and attractive renewable source of heterogeneous CaO catalyst for biodiesel production.

A PEGylation Technology of L-Asparaginase with Monomethoxy Polyethylene Glycol-Propionaldehyde

2012 ◽  
Vol 67 (5-6) ◽  
pp. 312-318 ◽  
Author(s):  
Bochu Wang ◽  
Yang Cao ◽  
Shaoping Chi ◽  
Deshuai Lou
Keyword(s):  
Polyethylene Glycol ◽  
Reaction Time ◽  
Anion Exchange ◽  
Gel Filtration ◽  
Molar Ratio ◽  
Protein Drugs ◽  
Amino Groups ◽  
Reaction Parameters ◽  
Optimum Reaction ◽  
Terminal Amino

Polyethylene glycol (PEG) conjugation technology has been successfully applied to improve the performance of protein drugs. In this study, L-asparaginase was N-terminal sitespecifically modified by alkylating PEG with monomethoxy polyethylene glycol-propionaldehyde (mPEG-ALD20000). The optimum reaction parameters were determined as pH 5.0, a molar ratio of mPEG-ALD20000 to L-asparaginase of 10:1, a reaction time of 16 h and temperature of 25 °C. PEG-L-asparaginase (PEG-L-ASNase) was isolated and purified with consecutive anion-exchange (XK, 16 × 20 cm, Q Sepharose FF) and gel-filtration (Tricorn, 10 × 600 cm, Sephacryl S-300 HR) chromatography, respectively. PEG-L-ASNase retained 43.5% of its activity and the N-terminal amino groups were modified to an extent of 3.67%

Research on Synthesis Regularity of Epoxysuccinic Acid

2013 ◽  
Vol 316-317 ◽  
pp. 942-945
Author(s):  
Qing He Gao ◽  
Yi Can Wang ◽  
Zhi Feng Hou ◽  
Hui Juan Qian ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Maleic Anhydride ◽  
Reaction Temperature ◽  
Raw Material ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Synthesis System ◽  
Reaction Conditions ◽  
Sodium Hydrate

The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.

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