Batch Cooling Crystallization of Plate-like Crystals: A Simulation Study

In the paper, batch cooling crystallization of plate-like crystals is investigated by numerical experimentation. The population balance approach is used to describe a seeded crystallization process, developing a bivariate morphological population balance model including nucleation and size dependent crystal growth. The population balance equation is reduced to a system of equations for the bivariate mixed moments of internal variables, which are solved by means of the quadrature method of moments. A sensitivity analyses is carried out to investigate the effects of the process parameters on dynamic evolution of particulate properties including the characteristic mean particle size and shape

Modelling and Simulation of Particle Size Distribution of Precipitates in Continuous Tubular Crystallizers

This paper presents a population balance model for describing the temporal evolution of the particle size distribution of a precipitate produced in a laboratory scale tubular crystallizer, including nucleation, growth and agglomeration of crystals. The quadrature method of moments is used to calculate the moments of the crystal size distribution. The gamma probability density function with the sixth order Laguerre polynomials are used to reproduce the particle size distribution from moments. A sensitivity analyses is carried out by simulation that can be helpful when designing a crystallizer. Influence of the design and process parameters on the particle size distribution of product is analysed

Modelling of Hybrid Method for VOC Removal from Process Wastewater: Distillation and Hydrophilic Pervaporation

The study is motivated by the industrial problem from pharmaceutical industry, which is ethanol and methanol removal from process wastewater. To complete this goal hybrid method is investigated and optimized. Two distillation columns are sufficient for separation of alcohol-water mixture. Suitable water can be purified as bottom product of first column. Ethanol and methanol purification is achieved with combination of second distillation column and pervaporation. The target of this research is to rigorously model and optimize the separation of water-ethanol-methanol ternary mixture in professional flowsheet simulator environment. The minimal sufficient membrane transfers area and number of minimal theoretical stages of the columns are determined. Cost estimation is also investigated according to Douglas methodology. Considering the simulation and economic results it can be determined that, the hybrid configuration is suitable for separation of ternary mixture in 99.5 weight percent purity

Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions

Nanometer-scale resistive switching devices operated in the metallic conductance regime offer ultimately scalable and widely reconfigurable hardware elements for novel in-memory and neuromorphic computing architectures. Moreover, they exhibit high operation speed at low power arising from the ease of the electric-field-driven redistribution of only a small amount of highly mobile ionic species upon resistive switching. We investigate the memristive behavior of a so-far less explored representative of this class, the Ag/AgI material system in a point contact arrangement established by the conducting PtIr tip of a scanning probe microscope. We demonstrate stable resistive switching duty cycles and investigate the dynamical aspects of non-volatile operation in detail. The high-speed switching capabilities are explored by a custom-designed microwave setup that enables time-resolved studies of subsequent set and reset transitions upon biasing the Ag/AgI/PtIr nanojunctions with sub-nanosecond voltage pulses. Our results demonstrate the potential of Ag-based filamentary memristive nanodevices to serve as the hardware elements in high-speed neuromorphic circuits

Sustainable technology solutions for reuse of process wastewaters from fine chemical industries

In the fine chemical industries, especially in the pharmaceutical industry, production technology generates large amounts of liquid waste and industrial waste solvents. Separation of various organic substances used in industry, such as adsorbable organic halides (AOX), from industrial wastewater is an important task of environmental protection. In this work, two technologies were compared to investigate the recycling/reuse of organic material of process wastewaters. The analysis was based on real case study from fine chemical industry. The separation efficiency, operational parameters and cost analysis were carried out to examine stripping and distillation technologies. The calculation was achieved in professional flowsheet simulator environment. According to the results, it can be determined there is no significant difference in separation efficiency of wastewater output streams. However, in the case of distillation technology, the reuse of halides can be possible inside the factory, so this is the recommended procedure for environmental protection. The cost of recovery technologies is also compared with waste incineration. These calculations also demonstrate the effectiveness of the treatment methods, because with recovery technologies it is possible to obtain a reduction of up to 85% compared to incineration