scholarly journals Biodegradation of 1,2,3-Trichloropropane to Valuable (S)-2,3-DCP Using a One-Pot Reaction System

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 3 ◽  
Author(s):  
Tadesse Fantaye Bogale ◽  
Ijaz Gul ◽  
Le Wang ◽  
Jiao Deng ◽  
Yong Chen ◽  
...  
Keyword(s):  
Batch Reactor ◽  
Scale Up ◽  
Environmental Pollutants ◽  
Reaction System ◽  
Liquid Waste ◽  
One Pot ◽  
Original Activity ◽  
Product Removal ◽  
Enantioselective Resolution ◽  
Carcinogenic Effects

1,2,3-trichloropropane (TCP) being one of the important environmental pollutants, has drawn significant concern due to its highly toxic and carcinogenic effects. In this study, we built a one-pot reaction system in which immobilized haloalkane dehalogenase (DhaA31) and halohydrin dehalognase (HheC) were used to catalyze the recalcitrant TCP to produce 2,3-dichloro-1-propanol (2,3-DCP) by removing epichlorohydrin (ECH). Since HheC displays a high R enantiopreference toward 2,3-DCP, the production of enantiopure (S)-2,3-DCP was expected. However, the enantioselective resolution of (R,S)-2,3-DCP by HheC was greatly inhibited by the circular reaction occurring between the product ECH and 1,3-dichloro-2-propanol (1.3-DCP). To resolve this problem, HZD-9 resin-based in situ product removal was implemented. Under the optimized conditions, TCP was completely consumed, resulting in optically pure (S)-2,3-DCP with enantiomer excess (e.e) > 99% and 40% yield (out of the 44% theoretical maximum). The scale-up resin-integrated reaction system was successfully carried out in 0.5 L batch reactor. Moreover, the system could be reused for 6 rounds with 64% of original activity retained, showing that it could be applied in the treatment of large volumes of liquid waste and producing enantiopure (S)-2,3-DCP.

PENGGUNAAN AIR SUPER KRITIS PADA DEPOLIMERISASI NYLON-12 (BATCH PROCESS)

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Mohamad Yusman
Keyword(s):  
Supercritical Water ◽  
Scale Up ◽  
Experimental Studies ◽  
Reaction System ◽  
Batch Process ◽  
Chemical Recycling ◽  
Water Decomposition ◽  
Product Distributions ◽  
New Process ◽  
Nylon 12

Water at the supercritical state is a new process for the chemical recycling. At this thermodynamic state i.e. Pc = 218 atmospheres and Tc = 374oC , water behaves very differently from its everyday temperament and it is a very good solvent for organic components. Experimental studies show that supercritical water can decompose hydrocarbons/polymers and produce useful products like 2-Azacyclotridecanone /lactam-1 from Nylon-12 (batch process). The decomposition process itself was carried out in batch reaction system in order to get more information about product distributions, time dependence, and scale-up possibilities.Keywords: supercritical water, decomposition, batch, polymer, hydrocarbon

scholarly journals Facile Hydrothermal and Solvothermal Synthesis and Characterization of Nitrogen-Doped Carbon Dots from Palm Kernel Shell Precursor

2021 ◽  
Vol 11 (4) ◽  
pp. 1630
Author(s):  
Yakubu Newman Monday ◽  
Jaafar Abdullah ◽  
Nor Azah Yusof ◽  
Suraya Abdul Rashid ◽  
Rafidah Hanim Shueb
Keyword(s):  
Carbon Dots ◽  
Batch Reactor ◽  
Average Particle Size ◽  
Research Work ◽  
Palm Kernel ◽  
Average Particle ◽  
One Pot ◽  
Palm Kernel Shell ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Carbon dots (CDs), a nanomaterial synthesized from organic precursors rich in carbon content with excellent fluorescent property, are in high demand for many purposes, including sensing and biosensing applications. This research focused on preparing CDs from natural and abundant waste, palm kernel shells (PKS) obtained from palm oil biomass, aiming for sensing and biosensing applications. Ethylenediamine and L-phenylalanine doped CDs were produced via the hydrothermal and solvothermal methods using one-pot synthesis techniques in an autoclave batch reactor. The as-prepared N-CDs shows excellent photoluminescence (PL) property and a quantum yield (QY) of 13.7% for ethylenediamine (EDA) doped N-CDs (CDs-EDA) and 8.6% for L-phenylalanine (L-Ph) doped N-CDs (CDs-LPh) with an excitation/emission wavelength of 360 nm/450 nm. The transmission electron microscopy (TEM) images show the N-CDs have an average particle size of 2 nm for both CDs. UV-Visible spectrophotometric results showed C=C and C=O transition. FTIR results show and confirm the presence of functional groups, such as -OH, -C=O, -NH2 on the N-CDs, and the X-ray diffraction pattern showed that the N-CDs were crystalline, depicted with sharp peaks. This research work demonstrated that palm kernel shell biomass often thrown away as waste can produce CDs with excellent physicochemical properties.

scholarly journals Production of lactic acid from cellulose using solid catalyst

2019 ◽  
Vol 268 ◽  
pp. 07006 ◽  
Author(s):  
Sujitra Doungsri ◽  
P. Rattanaphanee ◽  
Aatichat Wongkoblap
Keyword(s):  
Lactic Acid ◽  
Batch Reactor ◽  
Nitrogen Pressure ◽  
Reaction Pathways ◽  
Solid Catalyst ◽  
One Pot ◽  
Solid Catalysts ◽  
Platform Chemicals ◽  
Acid And Base ◽  
The One

Lactic acid (LA), one of the important biomass derived platform chemicals, has been used in food and chemical industries, especially in biodegradable polymer as polylactic acid (PLA). The aim of this work is to study the one-pot production of LA from cellulose by using different solid catalysts. The reaction was conducted in a high pressure batch reactor and the catalyst used in this study were ZrO2 and Al2O3. The reaction was carried out at temperature of 200oC for 6 hr. and under nitrogen pressure of 1 MP. It was found that the production yield of LA were 8.02% and 6.63%, when the ZrO2 and Al2O3 catalysts were used respectively. The result indicated that the ZrO2 may effect on the LA production because of the acid and base sites of the ZrO2. Therefore, the reaction pathways for conversion of cellulose into lactic acid have been investigated, and developed the new conditions to achieve the higher yield.

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

Optimal experimental design and artificial neural networks applied to the photochemically enhanced Fenton reaction

2001 ◽  
Vol 44 (5) ◽  
pp. 339-345 ◽  
Author(s):  
S. Göb ◽  
E. Oliveros ◽  
S.H. Bossmann ◽  
A.M. Braun ◽  
C.A.O. Nascimento ◽  
...  
Keyword(s):  
Neural Networks ◽  
Hydrogen Peroxide ◽  
Artificial Neural Networks ◽  
Fenton Reaction ◽  
Irradiation Time ◽  
Batch Reactor ◽  
Reaction System ◽  
Process Conditions ◽  
Minor Effect ◽  
Artificial Neural

Among advanced oxidation processes (AOPs), the photochemically enhanced Fenton reaction may be considered as one of the most efficient for the degradation of contaminants in industrial wastewater. This process involves a series of complex reactions. Therefore, an empirical model based on artificial neural networks has been developed for fitting the experimental data obtained in a laboratory batch reactor for the degradation of 2,4-dimethyl aniline (2,4-xylidine), chosen as a model pollutant. The model describes the evolution of the pollutant concentration during irradiation time as a function of the process conditions. It has been used for simulating the behavior of the reaction system in sensitivity studies aimed at optimizing the amounts of reactants employed in the process, an iron(III) salt and hydrogen peroxide, as well as the temperature. The results show that the process is most sensitive to the concentration of iron(III) salt and temperature, whereas the concentration of hydrogen peroxide has a minor effect.

scholarly journals Zinc Chloride Catalyzed Amino Claisen Rearrangement of 1-N-Allylindolines: An Expedient Protocol for the Synthesis of Functionalized 7-Allylindolines

2019 ◽  
Vol 25 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Seema Jain
Keyword(s):  
Zinc Chloride ◽  
Claisen Rearrangement ◽  
Reaction System ◽  
Biologically Active ◽  
Catalyst Loading ◽  
One Pot ◽  
Substitution Pattern ◽  
Claisen Rearrangements ◽  
Lower Temperature ◽  
Molecular Libraries

Abstract7-Allylindolines are valuable synthons for designing biologically active molecular libraries. Lewis acid catalyzed amino-Claisen rearrangement provides a one pot synthetic entry to these heteroarenes. In this context, Zinc chloride (ZnCl2)–N,N-dimethylformamide system efficiently catalyzed amino-Claisen rearrangements of 1-N-allylindolines to 7-allylindolines. The rearrangement is influenced by stereoelectronic effects of substituents present in 1-N-allylindolines. The substrates containing electron donating functionalities underwent rearrangement at lower temperature than substrates with electron withdrawing functional groups. The regioselectivity of the process is governed by the substitution pattern on allyl moiety in 1-N-allylindoline as well as ZnCl2 catalyst loading in the reaction system.

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