Study of Bunsen reaction in agitated reactor operating in counter current mode for iodine-sulphur thermo-chemical process

2016 ◽  
Vol 3 (1) ◽  
pp. 12
Author(s):  
A. Shriniwas Rao ◽  
S. Sujeesh ◽  
Nafees A. Vakil ◽  
H.Z. Fani ◽  
A. Sanyal ◽  
...  
Keyword(s):  
Chemical Process ◽  
Current Mode ◽  
Reactor Operating ◽  
Counter Current

scholarly journals Counter-Current Leaching of Low-Grade Laterites with Hydrochloric Acid and Proposed Purification Options of Pregnant Solution

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 599 ◽  
Author(s):  
Christiana Mystrioti ◽  
Nymphodora Papassiopi ◽  
Anthimos Xenidis ◽  
Konstantinos Komnitsas
Keyword(s):  
Hydrochloric Acid ◽  
Current Mode ◽  
Leach Solution ◽  
Low Grade ◽  
Mode Of Operation ◽  
Oxidative Precipitation ◽  
Alkaline Earths ◽  
Low Levels ◽  
Counter Current ◽  
Mn Oxides

A hydrochloric acid hydrometallurgical process was evaluated for Ni and Co extraction from a low-grade saprolitic laterite. The main characteristics of the process were (i) the application of a counter-current mode of operation as the main leaching step (CCL), and (ii) the treatment of pregnant leach solution (PLS) with a series of simple precipitation steps. It was found that, during CCL, co-dissolution of Fe was maintained at very low levels, i.e., about 0.6%, which improved the effectiveness of the subsequent PLS purification step. The treatment of PLS involved an initial precipitation step for the removal of trivalent metals, Fe, Al, and Cr, using Mg(OH)2. The process steps that followed aimed at separating Ni and Co from Mn and the alkaline earths Mg and Ca, by a combination of repetitive oxidative precipitation and dissolution steps. Magnesium and calcium remained in the aqueous phase, Mn was removed as a solid residue of Mn(III)–Mn(IV) oxides, while Ni and Co were recovered as a separate aqueous stream. It was found that the overall Ni and Co recoveries were 40% and 38%, respectively. About 45% of Ni and 37% of Co remained in the leach residue, while 15% Ni and 20% Co were lost in the Mn oxides.

Hot test of partitioning strontium from high-level liquid waste (HLLW) by dicyclohexano-18crown-6 (DCH18C6)

2001 ◽  
Vol 89 (3) ◽  
Author(s):  
W. Jianchen ◽  
S. Chongli
Keyword(s):  
Crown Ether ◽  
Liquid Waste ◽  
Current Mode ◽  
Feed Solution ◽  
High Level Liquid Waste ◽  
Trpo Process ◽  
Centrifugal Contactor ◽  
High Level ◽  
Counter Current ◽  
Hot Test

The crown ether strontium extraction(CESE) process for partitioning strontium from HLLW was studied. A hot test was carried out in a counter current mode with genuine HLLW by using a miniature centrifugal contactor set. 0.1 mol/L DCH18C6 in 1-octanol was used as extractant. The feed solution was the HLLW raffinate of TRPO process after removing TRU elements. Acidity of the feed was 1.45 mol/L HNO

scholarly journals Prospective Evaluation of Spent Sulfuric Acid Recovery by Process Simulation

2020 ◽  
Author(s):  
Krisztina Várnai ◽  
László Petri ◽  
Lajos Nagy
Keyword(s):  
Sulfuric Acid ◽  
Energy Consumption ◽  
Process Simulation ◽  
Azeotropic Distillation ◽  
Current Mode ◽  
Prospective Evaluation ◽  
Simulation And Optimization ◽  
Acid Recovery ◽  
Steady State Simulation ◽  
Counter Current

This study presents the steady-state simulation and optimization with regard to the recovery of spent sulfuric acid. Our purpose was to prove the utility of process simulation in terms of designing with special materials using energy-efficient methods. Process simulation is used in order to compare technological variants, analyze technological problems that occur as well as optimize the process. In this investigation three concentration processes are compared: azeotropic distillation and multiple-effect evaporation both in co-current and counter-current modes. The main aspects of the comparison are energy consumption and heat efficiency. Process simulation is an adequate tool for analyzing the thermal decomposition of sulfuric acid, the presence of sulfuric acid in the vapor fraction, and the costs of applying a third agent. Here, three models and a simulation-based prospective evaluation of energy consumption and the economy are presented. It is shown that the process of azeotropic distillation consumes an extremely large amount of thermal energy which seems to be more than that consumed by single-effect evaporation, while triple-effect evaporation in the counter-current mode was found to be the most thermally efficacious.

scholarly journals Closed-Loop Recycling Dual-Mode Counter-Current Chromatography with Specified Sample Loading Durations: Modeling of Preparative and Industrial-Scale Separations

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6561
Author(s):  
Artak E. Kostanyan ◽  
Andrey A. Voshkin
Keyword(s):  
Theoretical Analysis ◽  
Closed Loop ◽  
Current Mode ◽  
Operating Mode ◽  
Dual Mode ◽  
Sequential Separation ◽  
Mathcad Software ◽  
Counter Current ◽  
Further Development ◽  
Continuous Loading

We previously reported on a new counter-current chromatography (CCC) operating mode called closed-loop recycling dual-mode counter-current chromatography (CLR DM CCC), which incorporates the advantages of closed-loop recycling (CLR) and dual-mode (DM) counter-current chromatography and includes sequential separation of compounds in the closed-loop recycling mode with the mobile x-phase and in the inverted-phase counter-current mode with the mobile y-phase. The theoretical analysis of several implementations of this separation method was carried out under impulse sample injection conditions. This study is dedicated to the further development of CLR DM CCC theory applied to preparative and industrial separations, where high-throughput operation is required. Large sample volumes can be loaded via continuous loading within a specified time. To simulate CLR DM CCC separations with specified sample loading durations, equations are developed and presented in “Mathcad” software.

Performance Study of a Thermally Double Coupled Multi-Tubular Reactor by Considering the Effect of Flow Type Patterns

2016 ◽  
Vol 14 (1) ◽  
pp. 63-78 ◽  
Author(s):  
Mohsen Abbasi ◽  
Mehdi Farniaei ◽  
Sedigheh Kabiri ◽  
Mohammad Reza Rahimpour ◽  
Saeid Abbasi
Keyword(s):  
Current Flow ◽  
Tubular Reactor ◽  
Current Mode ◽  
Superior Performance ◽  
Performance Study ◽  
Reversed Flow ◽  
One Dimensional ◽  
Production Of Hydrogen ◽  
Simulation Results ◽  
Counter Current

AbstractIn this study, a steady-state heterogeneous one-dimensional model predicts the performance of a thermally double coupled auto-thermal multi-tubular reactor for simultaneous production of hydrogen, benzene, methanol and dimethyether (DME) in an economical approach for both co- and counter- current modes of operation. Reversed flow of cyclohexane has been considered for the counter-current flow regime. The simulation results for co- and counter-current modes have been investigated and compared with corresponding predictions for conventional methanol reactor and traditional coupled methanol reactor. In addition, various operating parameters along the reactor have been studied. The simulation results present that methanol yield in co- and counter- current modes are reached to 0.3735 and 0.3363 in a thermally double coupled reactor, respectively. Also, results for counter-current mode show a superior performance in hydrogen and benzene production. Finally, the results of simulation illustrate that the coupling of these reactions could be beneficial.

Modeling and Comparison a Thermally Coupled Reactor of Methane Tri – Reforming and Dehydrogenation of Cyclohexane Reactions for Syngas Production in Both Co- & Counter-Current Modes

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
E. Dehghanfard ◽  
Z. Arab Aboosadi
Keyword(s):  
Fixed Bed ◽  
Current Mode ◽  
Superior Performance ◽  
Hydrogen Yield ◽  
The Novel ◽  
One Dimensional ◽  
Syngas Production ◽  
Dehydrogenation Of Cyclohexane ◽  
Double Pipe ◽  
Counter Current

Abstract The aim of this work is a comparison of different inlets (Co- and Counter-current modes) to feed a thermally coupled reactor (TCR) in producing syngas as a valuable chemical. The novel thermally coupled reactor has been designed as a double pipe reactor where tri-reforming of methane for syngas production has been considered in the exothermic side of fixed bed plug reactor, and dehydrogenation of cyclohexane reaction occur in the endothermic side. The heat generated in the exothermic part by the walls of the tube side is transferred to the endothermic section. A steady-state homogeneous one-dimensional model predicts the performance of this reactor for simultaneous production of synthesis gas and benzene in an economical approach for both co- and counter-current modes of operation. The reversed flow of cyclohexane has been considered for the counter-current flow regime. The simulation results of co- and counter-current modes of TCR and also an optimized tri-reforming of methane (OTRM) single reactor are investigated and compared with each other. The results showed that methane conversion, hydrogen yield and ${H_2}/Co$ ratio in the exothermic side of TCR reached to 91.1 %, 1.82 and 2.1 in co-current mode and 87.8 %, 1.77 and 2.3 in counter-current mode, respectively. Additionally, the results showed that cyclohexane conversion at the endothermic side of the reactor in co- and counter-current modes achieved to 98.6 % and 99.9 %, respectively. So, the results for counter-current mode showed superior performance in hydrogen and benzene production in the endothermic side of TCR. Also, Changes in various operating parameters during the reactor have been studied.

Systematic Error for Extraction of Controlled Substances from Plant/Fungal Materials

2020 ◽  
Vol 58 (10) ◽  
pp. 985-991
Author(s):  
Júlia Nagy ◽  
Tibor Veress
Keyword(s):  
Mathematical Model ◽  
Systematic Error ◽  
Current Mode ◽  
Liquid Extraction ◽  
Salvinorin A ◽  
Preliminary Treatment ◽  
Extraction Recovery ◽  
Other Substances ◽  
Counter Current

Abstract The aim of this work was to investigate the applicability of a mathematical model developed for the description of supercritical fluid extraction (SFE) of cannabinoids from marijuana and hashish for liquid extraction of other substances. The mentioned model is applicable for dynamic SFE whose implementation is analogous to liquid–solid extraction in quasi-counter current mode. According to this model, quasi-counter current liquid–solid extractions were designed by calculation of component transport constants for extractions of psilocin from hallucinogenic mushroom, mescaline from hallucinogenic cactus, harmine from tropical lyan and salvinorin A from hallucinogenic sage. The mentioned model was found to be suitable for the determination of extraction time needed to reach a predefined extraction recovery for quasi-counter current liquid–solid extractions, as well, which allows the elimination of systematic error caused by the non-extracted part. The calculated component transport constants predict the expectable velocity of the extraction, i.e., the higher the component transport constant is, the higher the extraction velocity is. For mushrooms, it could be stated that preliminary treatment of mushrooms with liquid nitrogen significantly increases the extractability of psilocin.

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