Alexandr Zubov

University of Chemistry and Technology Prague · Department of Chemical Engineering

Redox flow batteries of various chemistries are potential electrochemical energy storages for residential accumulation and grid stabilization. Decoupled power and capacity represent the main advantages of the technology. The key component of the battery, the carbon felt electrode, does not participate in the electrochemical reaction directly, but i...

Density gradient theory describes the evolution of diffuse interfaces in both mixtures and pure substances by minimization of the total free energy, which consists of a non-convex bulk part and an interfacial part. Minimization of the bulk free energy causes phase separation while building up the interfacial free energy (proportional to the square...

Global sensitivity analysis (GSA) is a powerful tool for quantifying the effects of model parameters on the performance outputs of engineering systems, such as wastewater treatment plants (WWTP). Due to the ever-growing sophistication of such systems and their models, significantly longer processing times are required to perform a system-wide simul...

Understanding the biorecognition and transduction mechanisms is a key aspect in the development of robust sensing technologies. Therefore, the design of tools and analytical approaches that could allow gaining a deeper insight into the bio- and electrochemical processes would significantly accelerate the progress in the field of biosensors. Herein,...

Surrogate modeling (also referred to as metamodeling) has attracted increased attention from researchers in various fields of engineering due to its use in computationally expensive engineering tasks such as Monte Carlo based global sensitivity analysis and process design optimization. However, the applications of surrogate models in the field of w...

Development of predictive environmental property models is increasingly becoming crucial as stringent regulations for substances with high global warming and ozone depletion potentials are being introduced. This contribution presents new environmental property models using two group contribution (GC) based approaches for the prediction of ozone dep...

In this work we present a framework to generate surrogate models from rigorous process models embedded in a modelling environment or a process simulator. These unit operations (i.e. process flowsheet subsystems) are treated as black-box models to generate data for fitting and deriving the surrogate. Further, the methodology includes the formulation...

Poly(L-lactic acid) (PLLA) is a fully biodegradable bioplastic with promising market potential. The paper deals with systematic development and analysis of the modeling framework allowing direct mapping between PLLA production process conditions and rheological properties of the polymer melt. To achieve this, the framework builds upon three distinc...

Design, optimization and integration of biosensors hold a great potential for the development of cost-effective screening and point-of-care technologies. However, significant progress in this field can still be obtained on condition that sufficiently accurate mathematical models will be developed. Herein, we present a novel approach for the improve...

We respond to the comments by Glass and Mitsos regarding our approach to validation of binary liquid–liquid equilibrium data.

A simple model for binary liquid–liquid equilibrium data correlation is explored. The model describes liquid–liquid equilibrium in terms of Henry’s law and unsymmetrically normalized activity coefficients in each phase. A procedure for parameter estimation including an approach to initial guesses, uncertainty analysis of regression results, obtaine...

Due to hardening competition and increased focus on resource efficiency, efforts are made to develop advanced industrial optimization and control systems with the goal to shift the (semi-)batch production from recipe-based to a state-based approach. This study illustrates the steps needed for the implementation of optimization and on-line control o...

Semi-batch polymerization processes are traditionally operated according to rigidly prescribed recipes prohibiting process optimisation and product property adjustment in real time. In this contribution, we focus on the development of computationally efficient model of 4-monomer semi-batch emulsion copolymerization for the use in model-based predic...

Design of Wastewater Treatment Plants (WWTPs) is a complex engineering task which requires integration of knowledge and experience from environmental biotechnology, process engineering, process synthesis and design as well as mathematical programming. A methodology has been formulated and applied for the systematic analysis and development of plant...

Optimal processes often exhibit active path constraints. Parametric uncertainties in the process model might thus lead to constraint violations. A heuristic approach is presented to overcome this challenge. The nominal model is optimized with additional path constraints due to worst-case models. A heuristic method of choosing these models is propos...

Application properties of polymer foams are closely related to their morphology. Experimental characterization and subsequent morphological analysis thus represent essential tools for their investigation. Spatially three-dimensional porous structures of four closed-cell polyurethane foams are reconstructed using the X-ray micro-tomography (μCT) ima...

Real-time optimization-based control methodologies in emulsion (co)polymerization allow achievement of a significant intensification of the process and increase of the product quality. This paper describes the development of the fast and computationally simple process model of continuous styrene and n-butyl acrylate emulsion copolymerization for us...

Self-optimization of chemical reactions enables faster optimization of reaction conditions or discovery of molecules with required target properties. The technology of self-optimization has been expanded to discovery of new process recipes for manufacture of complex functional products. A new machine-learning algorithm, specifically designed for mu...

Advanced models of penetrant transport and reaction in spatially 3D porous polyolefin particles reconstructed from X-ray µCT images require proper determination of particle morphology. Moreover, polyolefins exhibit a relatively low absorptivity for X-rays, therefore their investigation using µCT can be difficult. In this paper, a low-resolution µCT...

This paper presents the deterministic model of styrene–butadiene cold emulsion copolymerization in the cascade of up to twelve reactors and its validation by the real industrial production of SBR. Model allows the dynamic prediction of basic latex properties (number and weight-average molecular weights, conversion of monomers) as well as the key qu...

We attempt to validate tomography-based spatially D model of polypropylene particle by comparison of model predictions with measured degassing characteristics of polypropylene powder samples. Statistically relevant number of porous PP particles from three particle size fractions is inspected by X-ray micro-tomography. The voxel size of reconstructe...

In this contribution porous polyolefin particles were digitally reconstructed from X-ray micro-computed tomography images with spatial resolution of about 3 micrometers. Calculation of transport and polymerization processes has been carried out in these spatially 3D reconstructed porous particles. The effect of particle structure on the diffusion a...

The 3D spatial structure of porous polyethylene particles was reconstructed from their X-ray micro-tomography images. Several polyolefin particles with an artificial granular structure were generated. Transport in reconstructed particles was calculated for the case of a monomer diffusing through both the pores and the polymer. The calculated degass...

Cover: A strategy to reliably reconstruct 3D images of porous polyolefin particles using X-ray microtomography is presented. Polyolefins exhibit low absorptivity for X-rays, hence they represent challenging samples for mCT imaging. Exploration of the influence of scanning/reconstruction settings on the resulting polymer morphology and transport cha...