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Recent Advances for Solid–Liquid Separation by Crystallization
Published in Olayinka I. Ogunsola, Isaac K. Gamwo, Solid–Liquid Separation Technologies, 2022
Alison E. Lewis, Torsten Stelzer
This chapter will focus on treatment technologies that use the concept of crystallization. Crystallization has been used since the dawn of civilization to crystallize out the salt from seawater in large open ponds or from underground saline for easier handling, storing, and trading of the salt.2 Therefore, it can surely be considered as one of the oldest separation technologies in chemical engineering. It represents the workhorse for separation tasks because it is often the most robust and cost-effective unit operation. Crystallization may be defined as a phase change in which a solid (crystalline) phase is generated from a liquid. This liquid feed can be either a solution composed of at least two or more solutes (species) in a solvent forming a homogeneous mixture or a melt that most correctly refers to a pure solid, molten above normal conditions. However, melts may be also homogeneous mixtures of more than one compound.
Methanol Conversions
Published in Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda, 1 Chemistry, 2022
Saeed Sahebdelfar, Maryam Takht Ravanchi, Ashok Kumar Nadda
Crystal seeds are building units that have an important role in crystallization and their introduction into the starting gel is desirable as the nucleation and consequently crystallization rate is accelerated (Sun et al., 2015).
State of the Art and Perspectives in Membranes for Membrane Distillation/Membrane Crystallization
Published in Andreas Sapalidis, Membrane Desalination, 2020
Carmen Meringolo, Gianluca Di Profio, Efrem Curcio, Elena Tocci, Enrico Drioli, Enrica Fontananova
Crystallization is a well-established unit operation for separation, purification, and for giving solid crystalline products from a liquid phase; it is employed in the chemical and pharmaceutical industries. MCr is an innovative crystallization process, put into operation by using membrane technology, by which crystals nucleation and growth is carried out in a well-controlled pathway, starting from an undersaturated solution. The large range of applications offered by the membranes and the future perspectives discussed in the literature present this technology as a promising and competitive alternative to conventional crystallizers for chemical production.
Effect of solution nonideality on cholesterol supersaturation for liquid antisolvent crystallization
Published in Chemical Engineering Communications, 2022
Shital D. Bachchhav, Sandip Roy, Mamata Mukhopadhyay
Crystallization is a process of formation of a solid disperse phase in a continuous medium of solution phase. The formation of solid particles from the solution requires a driving force for nucleation which is the chemical potential difference (Δµ) expressed through supersaturation (S) of the solid solute or the ratio of the solute activity values in the supersaturated and saturated solutions. In general, the choice of crystallization method depends on many factors, such as the physicochemical properties of the system, especially the crystallizing substance, the required product properties and the intended use of the product. Amongst the different methods used for the generation of supersaturation, the antisolvent crystallization is preferred in many applications because of the sharp and controlled reduction of solute solubility that is possible at near-ambient temperature (Rostagno and Prado 2013). The application of antisolvent crystallization processes have been demonstrated for a large range of systems: production of active pharmaceutical ingredients (Zhou et al. 2006; Tulcidas et al. 2019; Chen et al. 2020); Combined Cooling/Antisolvent Crystallization Processes (Schall et al. 2019); perovskite solar cells (Konstantakou et al. 2017); preparation of salt microparticles (Huang et al. 2020). In liquid-antisolvent process, a solid solute (3) is crystallized from its solution in solvent (2) by the addition of an antisolvent (1) in which the solute is relatively insoluble. The antisolvent can be in the form of a liquid, such as, water as in a liquid antisolvent (LAS) process.
Effect of crystallizer design and operational parameters on the batch crystallization of ibuprofen I: experimental
Published in Indian Chemical Engineer, 2022
Achyut Pakhare, Channamallikarjun Mathpati, Vishwanath H. Dalvi, Jyeshtharaj Joshi, Raosaheb Patil, Ekambara Kalekudithi
Crystallization is a unit operation extensively used in food, chemical, and pharmaceutical industries [1]. Crystal size and morphology of the product strongly affect the downstream processes such as filtration and drying [2]. Also, crystal morphology influences the flowability, packing, compaction, syringability, suspension stability, bioavailability, and dissolution characteristics of a drug powder [3]. Ibuprofen, an anti-inflammatory drug, is extensively used for the treatment of rheumatism, arthritis, fever, etc. Ibuprofen exhibit different crystal morphology in different solvents, as well as the size and aspect ratio, affect the flowability. The poor flowability affects the downstream operations in commercial manufacturing processes. These problems can be addressed at the crystallization step.
Synthesis and catalytic properties of ZSM-5 crystals with different morphologies in gelatin hydrogels
Published in Journal of Dispersion Science and Technology, 2021
Xueshuai Chen, Rongli Jiang, Zihan Zhou, Xingwen Wang
Essentially, the morphology of crystal is determined by the growth rate of the crystal faces which have different surface energies during the crystallization.[34] It is worth noting that gelatin plays important role for the formation of sheet-like ZSM-5 crystals. When the gelatin is absent in the starting aluminosilicate gels, the morphology of ZSM-5 crystals are high-degree intergrowth. When the starting gels have different mass ratios of the gelatin/H2O, ZSM-5 crystals uniformly formed with b-oriented have been successfully obtained. The scheme of the MFI-type zeolite was showed in Figure 5b. These results have demonstrated that the addition of gelatin has a strong interaction with the ZSM-5 nucleation, which promotes the preferential growth of (010) crystal plane, and ZSM-5 crystals with b-oriented lengths and well-dispersed have been successfully obtained. Meanwhile, it is also consistent with the conclusion that (010) plane is the most stable plan among the three crystal planes, and it is easier to absorb additives, and the preferential growth of (010) plane will inhibit the growth of b-axis direction.[35] As shown in Figure 5b, MFI-type zeolite possesses two channels including straight channels (5.3 × 5.6 Å) parallel to the b-axis and zigzag channels (5.1 × 5.5 Å) parallel to the a-axis. Generally, reactants and product molecules can enter these two channels randomly, but the diffusion rate of molecules in the straight channels is significantly higher than that in the zigzag channels due to the shape selectivity.[36] So controlling the b-axis thickness of ZSM-5 catalyst is very significant for the catalytic lifetime .