Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 23 for “"crystal size distribution"”.
-
Novel continuous crystallization configurations for improved yield, purity and controlled crystal size distribution
Continuous crystallization process has potential advantages such as lower cost and improved flexibility in pharmaceutical production when compared to batch crystallization. A good continuous crystallization process should achieve a high product yield and purity comparable to current batch …
-
Modeling and experimental validation of a single-feed semi-batch precipitation process
Crystallization is a widely practiced unit operation throughout the chemical and pharmaceutical process industries. Despite its widespread application, crystallization still suffers a disproportionate number of process difficulties due to the complexity of the steps involved in the process. In …
-
DEVELOPMENT OF NOVEL DESIGN AND CONTROL APPROACHES FOR INTEGRATED CRYSTALLIZATION OPERATION AND SYSTEMS
Crystallization is an important separation and purification technique for a wide variety of solid products in pharmaceutical, food and fine chemical industries. The production of more than 90% of the active pharmaceutical ingredients (APIs) involves crystallization. Therefore, it is crucial to …
-
Modeling and Simulation of Antisolvent Crystallization: Mixing and Control
… the issues of mixing and control in antisolvent crystallization processes, and to aid the development of systematic and scientific design approaches. The first part presents the development of an algorithm that couples macromixing and micromixing models with the population balance equation. It …
-
Effect of antiscalants during eutectic freeze crystallization of a reverse osmosis retentate
Eutectic Freeze Crystallization (EFC) is a separation technique which involves simultaneous crystallization of water and solute under eutectic conditions. It can be applied to treatment of various industrial aqueous streams containing dissolved organic and inorganic contaminants, such as reverse …
-
Optimal Control of Antisolvent and Cooling Crystallization
Common quality requirements for crystallization products is so critical in the pharmaceutical industry, including the demands of the drug administration and customers (e.g. bioavailability, size uniformity, and polymorphic form) and the concern of the manufacturer for downstream processes such as …
-
Multiscale Modeling and Mechanistic Analysis of Crystallization and Particulate Processes
Crystallization is a critical separation and solid-form control step in pharmaceutical and materials manufacturing, yet the mechanisms to understand molecular interactions, nucleation, growth, and particle evolution remain incompletely understood. Key knowledge gaps persist in explaining how …
-
The design, development and testing of a non-invasive continuous crystalliser system for the study of calcium oxalate crystallisation processes
… for conventional MSMPR analysis. Various crystalliser offtakes and six system designs were developed and tested to allow measurements using the thermostatted flow cell. The flow cell allows for continuous measurement of the sample dispersion using a noninvasive monitoring instrument - a …
-
Primary and secondary crystal nucleation of pharmaceutics
Control of the crystallisation process is essential in the consistent and reliable production of many particulate materials in the pharmaceutical and chemical industries. Crystal Nucleation defines the crystal size distribution of the obtained crystal population affecting downstream operations. The …
-
Finite element and population balance models for food-freezing processes
… to consider product quality by modeling the ice crystal size distribution (CSD) throughout the hardening process. This is achieved through the use of population balance equations (PBE). Crystal size and corresponding hardened ice cream coarseness can be predicted through the PBE model presented …
-
Phase behaviour and crystal nucleation in complex multicomponent system
The continuing research and use of co-crystallisation for separation, purification and modification of pharmaceutical materials in multiple industrial sectors can be attributed to the potential for high control of product quality attributes. Nucleation is a key phenomenon in crystallisation that …
-
Crystalization studies in hollow fiber devices
Crystallization was examined under a new perspective and in a flow environment much different from that available in currently used industrial devices. Three crystallization techniques were tested in the unique flow environment offered by hollow fiber devices. In addition, a new type of heat …
-
A thermodynamic framework for the modeling and optimization of crystallization processes
Crystallization is a widely used chemical engineering separation unit operation process. Since this technique can produce high purity products it is used for the industrial production of many chemical compounds, such as pharmaceuticals, agrochemicals, and fine chemicals. The production of these …
-
Multidimensional population balance modeling and optimization of continuous reactive crystallization
… efficiency of filtration depends strongly on the crystal size distribution (CSD) and shape. Undesired gypsum CSD and shape not only prolong the filtration and bottleneck the plant's overall production, but also decrease the phosphate recovery from the wet cake. To optimize the process, a …
-
Historic and prehistoric volcanic activity on St Kitts and Nevis, West Indies: Controls on future hazard
… The geochemistry also showed that rapid crystallization, reheating and partial melting occurred in the shallow crust before eruption. Magma mingling occurred shortly before or syn-eruption. 9 Crystal Size Distribution (CSD) methods allowed decompression and ascent rates to be estimated, …
-
Stochastic modeling of nonisothermal antisolvent crystallization processes
… a stochastic approach to model antisolvent crystallization processes is addressed. The motivations to choice a stochastic approach instead of a population balance modeling has been developed to find a simple and an alternative way to describe the evolution of the Crystal Size Distribution …
-
Mathematical modeling and design of novel semi-continuous and continuous crystallizations
Crystallization is an important separation technology used for the purification of products during their final stages of manufacturing. Novel semi-continuous and continuous crystallization process designs are receiving increasing attention in pharmaceutical industry due to significant advantages in …
-
Control of polymorphism in continuous crystallization
… of studies on the process dynamics in continuous crystallization, in particular in yield improvement and impurity separation, the research community lacks the systematic understanding of the control of polymorphism in continuous crystallization. Variations in the polymorphism of the active …
-
Crystallization of calcium sulphate during phosphoric acid production : improving filtration through improvement in particle shape and size distribution
… sulfuric acid solution. The induced reactive crystallization process produces a side product of calcium sulfate hydrates, which become the filter media in the subsequent acid separation process. For most industrial processes, the dihydrate form of calcium sulfate crystals (gypsum) precipitates …
Page 1 of 2