The world is moving towards decarbonization policies in the energy and industrial sectors to bring down carbon dioxide release and reach net zero emissions. Technologies to capture CO₂ and use it as a feedstock to produce CO₂-based chemicals and biofuels via chemical or biochemical conversion pathways can potentially reduce the amount of CO₂ released. The paper serves the innovative scientific knowledge for CO₂ transformation via a biochemical pathway to microalgal biomass with its subsequent treatment to biofuels and bioproducts assuming milder climatic conditions (Central or Eastern Europe, Visegrad countries or climatically related world regions). The recent trends were critically reviewed for microalgal biorefinery to reach the sustainability of microalgal-based chemicals with added value, digestion, hydrothermal liquefaction, pyrolysis, and gasification of microalgal residues. Knowledge-based chemical process engineering analysis, systematic data synthesis, and critical technical evaluation of available life cycle assessment studies evaluated the sustainability of microalgal biorefinery pathways. The research showed that biological CO₂ fixation using water, seawater or wastewater to produce third-generation biomass is a promising alternative for bioethanol production via pretreatment, enzymatic hydrolysis, digestion, and distillation, and can be realized on a large scale in an economically viable and environmentally sound manner. Its best economically promising and sustainable pathway is perceived in producing microalgal-based nutraceuticals, bioactive medical products, and food products such as proteins, pigments, and vitamins. Machine learning methods for data mining, process control, process optimization, and geometrical configuration of reactors and bioreactors are the crucial research needs and challenges to implementing microalgal biorefinery in an operational environment.

This study explores the influence of blade design on the low-pressure extrusion process, which is relevant to techniques like spheronization. We investigate how blade geometry affects the extruded paste and final product properties. A model paste was extruded through a basket extruder with varying blade lengths to create distinct wedge gaps (20°, 26° and 32° contact angles). The theoretical analysis explored paste behavior within the gap and extrudate. A model material enabled objective comparison across blade shapes. Our findings reveal a significant impact of blade design on the pressure profile, directly influencing liquid distribution in the paste and extrudate. It also affects the required torque relative to extruder output. The findings of this study hold significant implications for continuous granulation, a technique employed in the pharmaceutical industry for producing granules with uniform size and properties. Understanding the influence of blade geometry on the extrusion process can lead to the development of optimized blade designs that enhance granulation efficiency, improve product quality, and reduce energy consumption. By tailoring blade geometry, manufacturers can achieve more consistent granule characteristics, minimize process variability, and ultimately produce pharmaceuticals with enhanced efficacy.

Selective adjustment of the properties of particular material agglomeration has its inherent place in the chemical, food, but especially in the pharmaceutical, industry. The requirement to produce an agglomerate with desired particle size at a given strength is often formulated. To create the targeted product, it is necessary to know the process parameters affecting the preparation of its features. This paper deals with survey distribution characteristics and compressibility changes of an agglomerate in dependence on the duration of the granulation process through the usage of the most modern devices working with particulate materials. The investigated product will be prepared for coating granulating disc designed at the Institute of Process Engineering, Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava.

The aim of this study was to find a suitable granulation method intended for the transformation of waste in powder form from nickel ore processing, into stable granules. Requirements for the granulate were a particle size of a few millimeters, high strength and low friability for trouble-free transportation and material handling. For their further use as a sorbent in bio-gas plants, the granules had to have high porosity. By applying non-compacting granulation methods, a granulate of the desired dimension and properties was created. The created granulates were analyzed by dynamic image analysis (DIA) and powder rheometer. A high shear granulation method was chosen as the best method for powder waste processing, in which the most sustainable granulates were created using a small amount of granulation liquid. The granules produced by this method had good strength, low friability and a porous structure.

This book provides a comprehensive overview of particulate materials, their properties, and the engineering principles underlying their processing. Particulate materials, ubiquitous in industries ranging from pharmaceuticals to construction, consist of discrete solid particles. Understanding the unique characteristics of these materials is crucial for designing efficient and effective processing equipment. The book delves into the key factors influencing the behavior of particulate materials, including particle size distribution, shape, surface properties, and inter-particle forces. It explores the concepts of bulk density, porosity, and permeability, and discusses how these properties impact material handling, mixing, separation, and compaction processes. The book also covers the theoretical foundations of particulate mechanics, such as the mechanics of granular materials. Additionally, it presents experimental techniques for characterizing the properties of particulate materials and discusses the design and operation of various processing equipment, including mills, classifiers, filters, and dryers. This book is intended for engineers, scientists, and students involved in the processing of particulate materials. It provides a solid foundation in the fundamental principles and practical applications of particulate technology.