scholarly journals The Reaction Extraction Combining Crystallization for Growth of Sodium Chloride in a Spray Fluidized Bed Crystallizer

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Dan Zheng ◽  
Jie Yan ◽  
Jun Chen ◽  
Zeqin Wang

At present, the crystal size of sodium chloride prepared by a traditional crystallization process (such as stirred crystallization) is inhomogeneous, and it has a great quantity of fine grains in crystallizer. This work presents a novel approach for the growth of sodium chloride from supersaturated solutions by reaction-extractive crystallization in a spray fluidized bed crystallizer (SFBC), in which sodium sulfate solution is transformed into potassium chloride and sulphuric acid based on a reactive extraction-crystallization process using triisooctylamine (TOL) in n-octanol as the extraction system. This paper mainly studies the effect of operating conditions (e.g., circulation flow rate, velocity ratio of oil and aqueous phases, crystallization temperature, hydraulic residence time, and feed velocity) on the crystal size distribution (CSD) during the crystallization process of sodium chloride in a SFBC. Experimental results show that the optimum conditions are 1.0362 m/s as the best circulation flow rate, 9.5 : 8.5 as the best velocity ratio of oil and aqueous phases, 313 K as the best temperature, 4320 s as residence time, and 8 mL.min−1 as the best feed velocity. Meanwhile, the proposed extraction kinetic model about extraction rates is developed and validated against data from the SFBC. And it proves that the reactive extraction system is controlled by diffusion and chemical reaction. Analysis of the extraction kinetic model and comparison with experiments reveal that the extraction kinetic model results are in well agreement with experiments. Furthermore, the uniform and large crystals can be obtained in a spray fluidized bed crystallizer without special concentration since extraction and crystallization are carried out in the same equipment. In addition, all of the sodium chloride products prepared under the optimal conditions in SFBC show a better CSD performance than the stirred crystallization. This research demonstrates that this process enables controlling the crystal size in a rather wide range, thus further underlining the potential of this technique for applications in the crystallization industry.

2012 ◽  
Vol 9 (2) ◽  
Author(s):  
Anita Pinalia

AP is the solid particles with the largest composition in compossite propellant, with fractions 60-80%. Rounded particles of AP indirectly gives better performance of propellant. Therefore we need experiment the crystallization process to produce rounded AP crystal. In this experiment, crystallization was conducted by using a controlled cooling system. Cooling is done through two stages and using a different coolant. The first stage of slow cooling using water (30°C), and continued rapid cooling with ethylene glycol (-27°C). These experiment generate 45.45 kg AP with a purity 99.67%, 40 mesh crystal size, crystal shape close to round, yield 39.71%. Keywords: Ammonium perchlorate, Crystallization, Rounded crystal


2021 ◽  
pp. 791-798
Author(s):  
Yao Zhang ◽  
Chen Lin ◽  
Juan Yu ◽  
Jindong Jiang ◽  
Fan Feng ◽  
...  

2015 ◽  
Vol 155 ◽  
pp. 6-12 ◽  
Author(s):  
Mark Daniel G. de Luna ◽  
Luzvisminda M. Bellotindos ◽  
Riño N. Asiao ◽  
Ming-Chun Lu

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 922
Author(s):  
Xiao Juan Liu ◽  
Yang Zhang ◽  
Xue Zhong Wang

In situ ATR-FTIR spectroscopy and imaging and image analysis were applied to the study of the multicomponent co-crystallization process involving S-valsartan and sacubitril in which LCZ696 crystals were formed. LCZ696 is a combination drug for use in heart failure that was approved by the FDA in 2015 following development by Novartis Pharmaceuticals. Though much work was reported on LCZ696 about its pharmacokinetic and pharmacodynamic effects in the evaluation and clinical testing, less attention was paid to study on the co-crystallization process. LCZ696 crystals have shown difficulties in filtration mainly due to the small particle size. In this work, LCZ696 crystals were prepared successfully by S-valsartan and sacubitril, and characterized by SEM, XRPD, TG-DSC and ATR-FTIR. ATR-FTIR and imaging and image analysis were used to monitoring solution concentration and investigating the co-crystallization mechanism. It revealed that the nucleation process was very slow compared with the transformation process, which is indication that the co-crystallization was controlled by nucleation. LCZ696 crystals are composed of very thin hexagonal plates, which seems indicating that LCZ696 crystals grow mainly in two size dimensions. Stirrer speed and crystal seeds were found to have noticeable effect on the induction time, transformation time and crystal size distribution. The Johnson-Mehl-Avrami equation was found to be able to describe the co-crystallization process.


2018 ◽  
Vol 789 ◽  
pp. 59-63
Author(s):  
Susmardi Masti Casoni ◽  
Chandra Wahyu Purnomo ◽  
Muslikhin Hidayat

The high organic material contained in wastewater released into the environment asresults of various sources of human activities, such as phosphorus, can cause eutrophication. Thestruvite crystallization in an aerated fluidized bed reactor is one of the methods which able toimprove the efficiency of phosphorus removal. In this study, a mixture of synthetic wastewaters andthe MgCl2 solution was treated in a fluidized bed reactor equipped with aeration to produce thestruvite which can be utilized as a slow release fertilizer. Subsequently, the effect of aeration atdifference influent flow rate was investigated to correlate with the changing of phosphorusconcentration in the reactor effluent. The experiments were conducted for 240 minutes with thevariation of aeration are 0.5 L/min to 1.5 L/min; variation of influent flow rate of syntheticwastewater is 150 ml/min to 350 ml/min, with a constant influent flow rate of MgCl2 solution is 50ml/min. These solutions were maintained at the condition of pH 9. The results showed that theoptimal efficiency of phosphor removal which accounted for 82.5% occurred when the aeration rateof 1.5 L/min in the influent flow rate of 150 ml/min. From these findings, it is revealed that theefficiency of P removal in wastewater is obtained by a crystallization process which utilizing anaerated fluidized bed reactor and by increasing the aeration rate and the reactants contact time.


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