Purification of 1,3-Propanediol for Production of Polytrimethylene Terephthalate (PTT) from Biomass

2011 ◽  
Vol 320 ◽  
pp. 191-195 ◽  
Author(s):  
Yeon Ki Hong

1,3-Propanediol (1,3-PDO) has received increasing attention due to usage as the monomer of biopolymer-polytrimethylene terephthalate (PTT) which can be produced from bioresources. For the economic production of 1,3-PDO, the deveolpment of cost effective removal process of by-products such as carboxylic acids from its fermentation broth. Amien-based extraction is the separation process using reactions between amine and materials extracted. The extractabilities for carboxylic acid increased with amine concentration and decreased with pH values. It was also observed that the removal efficiency of carboxylic acids from 1,3-PDO solution was above 90% without any coextraction of 1,3-PDO. From this work, it was found that the amine-based extraction can be promising separation process for the production of pure 1,3-PDO.

2021 ◽  
Author(s):  
Rongjie Yi ◽  
Qi Zhang ◽  
Chengwu Yi

The degradation of oxacillin in aqueous solution by strong ionization dielectric barrier discharge (DBD) was explored. The effects of input voltage, initial pH, initial concentration of solution and hydroxyl (·OH) inhibitor on the removal efficiency of OXA were investigated. The results showed that the removal efficiency of OXA with initial concentration of 20mg/L reached 91.5% under the optimal treatment conditions of 3.8 kV and 7.3 pH. With the higher voltage and the lower initial concentration, the removal effect was better. The pH of the solution has little effect on the removal efficiency, and the removal effect is the best in neutral aqueous solution. The inhibition effect of TBA was stronger than that of CO32- and HCO3-. Moreover, ·OH was the main active substance in the process of strong ionization discharge, which played a major role in the removal of OXA. In addition, two main by-products were identified, the transformation pathways including hydroxylation (+16 Da), decarboxylation (-44 Da) were observed. This study provided a theoretical basis for the effective removal of antibiotics in water by strong ionization discharge.


2012 ◽  
Vol 9 (4) ◽  
pp. 2297-2308 ◽  
Author(s):  
Edris Bazrafshan ◽  
Kamal Aldin Ownagh ◽  
Amir Hossein Mahvi

Fluoride in drinking water above permissible level is responsible for human being affected by skeletal fluorosis. The present study was carried out to assess the ability of electrocoagulation process with iron and aluminum electrodes in order to removal of fluoride from aqueous solutions. Several working parameters, such as fluoride concentration, pH, applied voltage and reaction time were studied to achieve a higher removal capacity. Variable concentrations (1, 5 and 10 mg L-1) of fluoride solutions were prepared by mixing proper amount of sodium fluoride with deionized water. The varying pH of the initial solution (3, 7 and 10) was also studied to measure their effects on the fluoride removal efficiency. Results obtained with synthetic solution revealed that the most effective removal capacities of fluoride could be achieved at 40 V electrical potential. In addition, the increase of electrical potential, in the range of 10-40 V, enhanced the treatment rate. Also comparison of fluoride removal efficiency showed that removal efficiency is similar with iron and aluminum electrodes. Finally it can be concluded that the electrocoagulation process has the potential to be utilized for the cost-effective removal of fluoride from water and wastewater.


Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4214 ◽  
Author(s):  
Cagide ◽  
Oliveira ◽  
Reis ◽  
Borges

6-Bromochromone-2-carboxylic acid (3) was synthesized by a microwave-assisted process. The optimization of the reaction was performed varying parameters, such as type of base/number of reagent equivalents, solvent, temperature and reaction time. The yield of the reaction was improved to 87%. The new synthetic route is versatile as several chromone-2-carboxylic acids (compounds 4B–10B) were obtained with good yields (54–93%). Only in the case of the nitro substituent (compound 11B), an ester was obtained instead of the desired carboxylic acid. Following this synthetic route chromone carboxylic acids can be attained with a high degree of purity, without the need of the tedious and expensive purification processes through column chromatography. The reaction is safe, cost-effective, fast and robust, and can be used in the development of concise and diversity-oriented libraries based on chromone scaffold. The overall study can be looked as a step forward to speed-up the discovery of chromone-based multitarget-directed ligands.


2012 ◽  
Vol 550-553 ◽  
pp. 634-638 ◽  
Author(s):  
Seong Ho Jung ◽  
Ki Sub Kim ◽  
Yeon Ki Hong ◽  
Byung Heung Park

Propionic acid has been received increasing attention due to its various usages as an antifungal agent in food and a chemical in the production of several chemical products. In order to develop an alternative production process of propionic acid such as fermentation of glycerol, the cost effective recovery process of propionic acid from its fermentation broth is needed. Differently from conventional physical extraction, long chain amine (TOA)-based extraction is the separation process using reactions between amine and materials extracted. The equilibrium distribution of propionic acid increased with amine concentration and decreased with increase of n-heptane composition in mixed diluents. From the loading values with TOA concentrations, it was found that the stoichiometries of acid-amine-1-octanol complex were (1,1) and (1,1,1). From this study, amine-based extraction can be promising separation process for the recovery of propionic acid.


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 756
Author(s):  
Rama Pulicharla ◽  
François Proulx ◽  
Sonja Behmel ◽  
Jean-B. Sérodes ◽  
Manuel J. Rodriguez

Ozonation is becoming a common disinfection method for drinking water treatment. This has prompted the investigation of ozonation disinfection by-products (ODBPs) in drinking water. Ozonation generates a diverse range of carbonyl disinfection by-products, including carboxylic acids, aldehydes, ketones and aldo-ketoacids. Among these ODBPs, carboxylic acid by-products (CABPs) are observed in higher concentrations compared to other carbonyl by-products. However, relatively little research has been conducted on CABPs, including their precursors, formation and occurrence, methods of detection and toxicity. This review outlines the occurrence and variability of CABPs in a number of water sources treated and disinfected with ozonation. It considers the effect of ozonation parameters, including ozone dose, temperature and time of ozonation on the formation of CABPs. The review also discusses the various analytical approaches for CABP quantification, as well as their possible toxicity in drinking water.


2001 ◽  
Vol 1 (4) ◽  
pp. 177-184
Author(s):  
B.I. Dvorak ◽  
J.W. Schauble

Environmental engineers are frequently faced with uncertainty in making design decisions because the true value of many process parameters is unknown. In this study, the design of countercurrent air stripping towers was modeled using fuzzy numbers, taking into account uncertainties in mass transfer and Henry's constant. It was found that, in addition to cost, the risk of failure is an important design consideration for stripping tower design. A significant over-design is both cost-effective and results in less risk of design failure. The air-to-water ratio that yielded the least risk of failure switched from low to high as the removal efficiency of the tower increased. An important result is that at lower removal efficiencies, tower design and operation is most sensitive to uncertainties in mass transfer and at higher removal efficiencies, tower design and operation is most sensitive to uncertainties in Henry's constant . The implication is that low air-to-water ratios are best when the regulatory target removal efficiency is low and/or when the uncertainty in the value of the contaminant's Henry's constant is larger than the uncertainty in the mass transfer coefficient value. Otherwise a high air-to-water ratio results in the least risk of process failure.


2018 ◽  
Vol 21 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Ghasem Marandi

Aim and Objective: The reaction of cyclohexylisocyanide and 2-aminopyridine-3- carboxylic acid in the presence of benzaldehyde derivatives in ethanol led to 3-(cyclohexylamino)-2- arylimidazo[1,2-a]pyridine-8-carboxylic acids in high yields. In a three component condensation reaction, isocyanide reacts with 2-aminopyridine-3-carboxylic acid and aromatic aldehydes without any prior activation. Material and Methods: The synthesized products have stable structures which have been characterized by IR, 1H, 13C and Mass spectroscopy as well as CHN-O analysis. Results: In continuation of our attempts to develop simple one-pot routes for the synthesis of 3- (cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8-carboxylic acids, aromatic aldehydes with divers substituted show a high performance. Conclusion: In conclusion, this study introduces the art of combinatorial chemistry using a simple one-pot procedure for the synthesis of new materials which are interesting compounds in medicinal and biological sciences.


2021 ◽  
pp. 174751982098715
Author(s):  
Khethobole C Sekgota ◽  
Michelle Isaacs ◽  
Heinrich C Hoppe ◽  
Ronnett Seldon ◽  
Digby F Warner ◽  
...  

Propylphosphonic acid anhydride has been successfully used as a coupling agent in the synthesis of a series of indolizine-2-carboxamido derivatives from indolizine-2-carboxylic acid and its 3-acetylated analogue. The acid substrates were obtained by saponification of the corresponding methyl esters produced, in turn, selectively and efficiently, by time-controlled cyclisation of a single Morita–Baylis–Hillman adduct. Various amino and hydrazino compounds with medicinal potential have been used to prepare indolizine-2-carboxamido and hydrazido derivatives.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4545
Author(s):  
Sudharsan Sadhasivam ◽  
Omer Barda ◽  
Varda Zakin ◽  
Ram Reifen ◽  
Edward Sionov

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by Penicillium and Aspergillus species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps. The method showed good performance in the analysis of these mycotoxins in apple and pear fruit samples with recovery ranges of 55–97% for PAT and 84–101% for CTN, respectively. The limits of detection (LOD) of PAT and CTN in fruits were 0.006 µg/g and 0.001 µg/g, while their limits of quantification (LOQ) were 0.018 µg/g and 0.003 µg/g, respectively. The present findings indicate that the newly developed HPLC method provides rapid and accurate detection of PAT and CTN in fruits.


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