Partition mechanism of adsorption and the absence of displacement phenomena in the zonal analytical chromatography of proteins on bead 2-hydroxy-3-phenoxypropyl-cellulose

1989 ◽  
Vol 54 (9) ◽  
pp. 2375-2385 ◽  
Author(s):  
Peter Gemeiner ◽  
Eva Hrabárová ◽  
Magdaléna Zacharová ◽  
Albert Breier ◽  
Milan J. Beneš
Keyword(s):  
Reaction Time ◽  
Perchloric Acid ◽  
Adsorption Mechanism ◽  
Spherical Shape ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Hydrophobic Region ◽  
Bead Cellulose ◽  
To Come

Hydrophobization of bead cellulose is described, carried out by its alkylation with 1,2-epoxy-3-phenoxypropane under the conditions of acid (perchloric acid, borontrifluoride diethyl etherate) and basic (sodium hydroxide) catalysis. Reaction conditions (temperature, reaction time, molar ratio of reactants) have been determined, allowing the hydrophobization of bead cellulose to be carried out to the largest possible extent while maintaining its spherical shape. The nonstoichiometric mechanism suggested for the adsorption of amphiphilic adsorptives on bead 2-hydroxy-3-phenoxypropyl-cellulose (HPP-C) was checked by means of adsorption of six proteins. It was found that the surface of the hydrophobic segment of the adsorbent must be sufficiently large to be able to come in touch with the hydrophobic region of the protein through its multiple residues. In such cases the partitioning of the protein between the hydrophobic segment present as a liquid-like film and the surrounding solution becomes the predominant step of the adsorption. This adsorption mechanism is also reflected in zonal chromatography on bead HPP-C, as no displacement phenomena could be observed in any of the six proteins used. Retention of these proteins has been affected to a decisive extent by the degree of hydrophobization of HPP-C.

Transesterification of NDC with EG: Effects of Reaction Conditions on NDC Conversion

2013 ◽  
Vol 807-809 ◽  
pp. 2774-2778
Author(s):  
Lin Ping Sun ◽  
Qian Qiao
Keyword(s):  
Reaction Time ◽  
Ethylene Glycol ◽  
Reaction Temperature ◽  
Zinc Acetate ◽  
Metal Salt ◽  
Metal Salts ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Transesterification of dimethyl 2,6-napthalene dicarboxylate with ethylene glycol over metal salts catalyst was empolyed as probe reation. The effects of reaction temperature, reaction time, the molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, N2 flowrate, kind of metal salt on the conversion of dimethyl 2,6-napthalene dicarboxylate have been investigated. The results showed that the sequence of influence was as follows: reaction temperature > reaction time > ethylene glycol/dimethyl 2,6-napthalene dicarboxylate molar ratio > amount of the catalyst. The optimum reaction conditions were 210 oC of reaction temperature, 240 min of reaction time, 2.8 molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, 60 ml/min of N2, amount of zinc acetate being 0.08 % / mole of dimethyl 2,6-napthalene dicarboxylate.

Selective Epoxidation of Styrene with Mn-TAML/TBHP

2014 ◽  
Vol 685 ◽  
pp. 133-136 ◽  
Author(s):  
Ge Wang ◽  
Ran Li ◽  
Ya Ru Liu ◽  
Hui Ying Liu ◽  
Zhi Min Sun ◽  
...  
Keyword(s):  
Reaction Time ◽  
Styrene Oxide ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Styrene Epoxidation ◽  
Reaction Conditions ◽  
Reaction Conversion ◽  
Tert Butyl Hydroperoxide ◽  
Optimum Reaction ◽  
Optimized Conditions

Styrene was selectively oxidized to styrene oxide with macrocylic amido Mn (II) complex as catalyst and tert-Butyl hydroperoxide (TBHP) as oxidant. The effects of reaction temperature, reaction time, solvents, amount of catalyst and oxidant on the conversion and selectivity of styrene epoxidation were investigated. The optimized conditions were achieved by molar ratio of n (catalyst) :n (styrene)=1% in acetonitrile solvent at 75 °C in 1.5 h. Under optimum reaction conditions, reaction conversion of 92.6% and selectivity of 86.9 % were obtained.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

scholarly journals Biodiesel Production from a Novel Nonedible Feedstock, Soursop (Annona muricata L.) Seed Oil

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2562 ◽  
Author(s):  
Chia-Hung Su ◽  
Hoang Nguyen ◽  
Uyen Pham ◽  
My Nguyen ◽  
Horng-Yi Juan
Keyword(s):  
Reaction Time ◽  
Seed Oil ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Annona Muricata ◽  
Reaction Conditions ◽  
Biodiesel Feedstock ◽  
Acid Catalyzed ◽  
American Society ◽  
Optimal Reaction

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.

scholarly journals High-Quality Biodiesel Production from Buriti (Mauritia flexuosa) Oil Soapstock

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 94 ◽  
Author(s):  
Samantha Pantoja ◽  
Vanessa Mescouto ◽  
Carlos Costa ◽  
José Zamian ◽  
Geraldo Rocha Filho ◽  
...  
Keyword(s):  
Reaction Time ◽  
Methyl Esters ◽  
Natural Antioxidants ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Palm Tree ◽  
Reaction Conditions ◽  
Mauritia Flexuosa ◽  
Buriti Oil ◽  
Brazilian Standard

The buriti palm (Mauritia flexuosa) is a palm tree widely distributed throughout tropical South America. The oil extracted from the fruits of this palm tree is rich in natural antioxidants. The by-products obtained from the buriti palm have social and economic importance as well, hence the interest in adding value to the residue left from refining this oil to obtain biofuel. The process of methyl esters production from the buriti oil soapstock was optimized considering acidulation and esterification. The effect of the molar ratio of sulfuric acid (H2SO4) to soapstock in the range from 0.6 to 1.0 and the reaction time (30–90 min) were analyzed. The best conditions for acidulation were molar ratio 0.8 and reaction time of 60 min. Next, the esterification of the fatty acids obtained was performed using methanol and H2SO4 as catalyst. The effects of the molar ratio (9:1–27:1), percentage of catalyst (2–6%) and reaction time (1–14 h) were investigated. The best reaction conditions were: 18:1 molar ratio, 4% catalyst and 14 h reaction time, which resulted in a yield of 92% and a conversion of 99.9%. All the key biodiesel physicochemical characterizations were within the parameters established by the Brazilian standard. The biodiesel obtained presented high ester content (96.6%) and oxidative stability (16.1 h).

Desulfurization from Gasoline by Polymer Resin at Room Temperature and Atmospheric Pressure

2011 ◽  
Vol 396-398 ◽  
pp. 1283-1286
Author(s):  
Jian Peng Zhu ◽  
Chun Hu Li ◽  
Jia Ling Chen ◽  
Ying Wei Luo
Keyword(s):  
Reaction Time ◽  
Sulfur Content ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Oxidative Desulfurization ◽  
Sulfur Compounds ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Polymer Resin ◽  
Mild Conditions

Abstract. Investigation of polymer resin as catalyst in the oxidative desulfurization (ODS) process has revealed that the method can be applied to make a relative high removal of sulfur compounds. The reaction conditions, including temperature, amount of oxidant and reaction time were studied. The best result occurs under mild conditions with respect to room temperature and atmospheric pressure, to remove 75.54% of the totle sulfur content in the presence of H2O2 with an O/S molar ratio of 17. Possible mechanism is also disscussed.

Selective aerobic allylic oxidation of α-pinene catalyzed by metalloporphyrins in the absence of solvents and additives

2019 ◽  
Vol 43 (9-10) ◽  
pp. 419-425 ◽  
Author(s):  
Huanhuan Dong ◽  
Shichao Xu ◽  
Jing Wang ◽  
Yuxiang Chen ◽  
Liangwu Bi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Flow Rate ◽  
Catalyst Concentration ◽  
Aerobic Oxidation ◽  
Oxygen Flow Rate ◽  
Oxidation Products ◽  
Allylic Oxidation ◽  
Temperature Reaction ◽  
Reaction Conditions

Selective aerobic oxidation of α-pinene to high-value products is a major challenge in chemistry. Metalloporphyrins are proved to be selective catalysts for aerobic oxidation of simple hydrocarbons. Herein, we extend this method to more complex substrates using metallodeuteroporphyrins as model catalysts. It was found that the oxidation occurs mainly on the C=C and allylic C–H bonds of α-pinene influenced by the reaction temperature, reaction time, catalyst concentration, and oxygen flow rate. Allylic C–H oxidation products are obtained with a maximum selectivity value of 78.4% using the following reaction conditions: 105°C, 7 h, 5 ppm, and 60 mL/min. The influence of the metal nuclei of the metallodeuteroporphyrins on this reaction is also investigated. It was found that metallodeuteroporphyrins with Fe3+ as the metal nucleus exhibit the highest catalytic activity.

Preparation and Characterization of Cationic Cassia Tora Gum

2013 ◽  
Vol 781-784 ◽  
pp. 526-530 ◽  
Author(s):  
Shao Ying Li ◽  
Chun Mei Niu ◽  
Hua Yu Zhong
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Water Solubility ◽  
Cold Water ◽  
Water Solution ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Cassia Tora ◽  
Dispersing Agent

Series of cationic cassia tora gum (CCTG) were synthesized using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) as cationic etherifying agent, isopropanol-water solution as dispersing agent, in presence of sodium hydroxide under different reaction conditions. The optimum ratio for preparing the cationic cassia tora gum are that CHPTAC-CTG molar ratio is 0.6:1; NaOH-CHPTAC molar ratio is 1.3:1.The optimum conditions are that reaction temperature is 55°Cand reaction time is 3.5 h. The cold water solubility was improved apparently. The solution transmittance has corresponding relationship with the nitrogen content (N%) in the certain range, and the maximum transmittance is up to 87.2%. N% increased with the increase of reaction time and stable N% can be obtained in shorter reaction time at higher reaction temperature. The products were characterized by 13C-NMR. The heat resistance of CTG and CCTG were analyzed.

Optimization of melon oil methyl ester production using response surface methodology

2017 ◽  
Vol 2 (1) ◽  
pp. 1-10 ◽  
Author(s):  
O. S. Aliozo ◽  
L. N. Emembolu ◽  
O. D. Onukwuli
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Methyl Ester ◽  
Response Surface ◽  
Research Work ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Central Composite Designs ◽  
American Society

Abstract In this research work, melon oil was used as feedstock for methyl ester production. The research was aimed at optimizing the reaction conditions for methyl ester yield from the oil. Response surface methodology (RSM), based on a five level, four variable central composite designs (CCD)was used to optimize and statistically analyze the interaction effect of the process parameter during the biodiesel production processes. A total of 30 experiments were conducted to study the effect of methanol to oil molar ratio, catalyst weight, temperature and reaction time. The optimal yield of biodiesel from melon oil was found to be 94.9% under the following reaction conditions: catalyst weight - 0.8%, methanol to oil molar ratio - 6:1, temperature - 55°C and reaction time of 60mins. The quality of methyl ester produced at these conditions was within the American Society for Testing and Materials (ASTM D6751) specification.

Catalytic Synthesis of Isoamyl Acetate Catalyzed by (NH4)6[MnMo9O32]•8H2O Supported Activated Carbon with Waugh Structure

2013 ◽  
Vol 781-784 ◽  
pp. 190-193
Author(s):  
Mei Xu ◽  
Hua Yuan ◽  
Wei Liu ◽  
Jian Wang ◽  
Feng Zhen Yang
Keyword(s):  
Acetic Acid ◽  
Activated Carbon ◽  
Reaction Time ◽  
Conversion Rate ◽  
Isoamyl Alcohol ◽  
Isoamyl Acetate ◽  
Catalytic Synthesis ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimum Reaction

The synthesis of isoamyl acetate with ammonium 9-molybdate manganese heteropolyacid salt supported activated carbon as catalyst was studied. The optimum reaction conditions are obtained as follows: isoamyl alcohol to acetic acid molar ratio = 1.646, the weight of catalyst is 40% of total weigh, m (acidulate catalyst)=0.2g, m (water carrying reagent toluene) = 3ml, reaction time is about 63 minutes. Selectivity is 100% and conversion rate is 89.48%.

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