Volume 37, Issue 1 - Special issue: Chemical engineering in Russia; Issue editor: Andrey N. Zagoruiko

The main aim of this article is to provide a state-of-the-art review of the magnetic resonance imaging (MRI) utilization in heterogeneous catalysis. MRI is capable to provide very useful information about both living and nonliving objects in a noninvasive way. The studies of an internal heterogeneous reactor structure by MRI help to understand the mass transport and chemical processes inside the working catalytic reactor that can significantly improve its efficiency. However, one of the serious disadvantages of MRI is low sensitivity, and this obstacle dramatically limits possible MRI application. Fortunately, there are hyperpolarization methods that eliminate this problem. Parahydrogen-induced polarization approach, for instance, can increase the nuclear magnetic resonance signal intensity by four to five orders of magnitude; moreover, the obtained polarization can be stored in long-lived spin states and then transferred into an observable signal in MRI. An in-depth account of the studies on both thermal and hyperpolarized MRI for the investigation of heterogeneous catalytic processes is provided in this review as part of the special issue emphasizing the research performed to date in Russia/USSR.

Exploration of confined swirled flows in the former USSR and present-day Russia has a long history and is presented by numerous publications, mostly written in Russian. The obtained results have been put to practical use in different areas of chemical, energy, and processing industries. In view of the process intensification concept, such characteristics of confined swirled flows may be considered unique: high centrifugal gravity, elongation of trajectories, the presence of internal separation zones, energy separation phenomena, and efficient mass/heat transfer in the absence of any moving parts. For instance, high gravity provides an excellent opportunity for multiphase flow stabilization, preventing the appearance of nonuniformities and stability loss, while enhancement of various driving forces acting on the reaction medium takes place. This review is devoted to outlining the main research trends and to discuss the most essential practical implementations in the subject matter done up until now. It is not foreseen to embrace the whole area of swirled flow investigations in the world, but only covers most of the significant ideas and applications contributed in by former Soviet and Russian scientists and engineers. Shortcomings and difficulties of using swirled flows are also briefly discussed.

Minimization of the costs with simultaneous increase in the raw materials and energy use efficiency is a challenge for the modern world. One of the most effective tools to solve this task is the use of process intensification (PI), first proposed by Ramshaw C. The incentive for process intensification, Proceedings, 1st Intl. Conf. Proc. Intensif. for Chem. Ind., 18, BHR Group, London, 1995, p. 1. and then extended by Stankiewicz AI, Moulijn JA. Process intensification: transforming chemical engineering. Chem Eng Prog 2000: 22–34. In the presented review, some principles of PI in chemical engineering and their application for wide variety of processes is discussed. The role of the Russian scientist with a research background is carried out in other countries.

This review analyzes alternative noncatalytic routes for the conversion of various natural hydrocarbon gases to syngas, oxygenates, olefins, and other chemicals. The possibility of producing a wide assortment of products directly from light gaseous hydrocarbons, including methane, was demonstrated. The advantages and practical implementations of such technologies are discussed.

In the last decade, novel approaches for post-synthesis processes of separation and high purification of gases are gaining larger acceptance in industry. The market is competing with consolidated operations such as cryogenic distillation. The key for new approaches of distillation, membranes and crystallization in challenging and harsh environments is the development of new tough, high-performance materials that are characterized by higher energy efficiency compared with conventional cryogenic distillation. This review highlights the most promising fields of research in high purification and separation of gases by considering the elevated pressure and thermal distillations, membrane cascades, purification in synthesis by use of catalytic technologies, crystallization and hydride methods based on them.

This review summarizes Russian developments on the most important industrial processes of hydrocarbon feedstock refining according to the data of the last 15–20 years on the kinetics of deactivation of heterogeneous and liquid-phase catalysts under non-stationary conditions. The methodological aspects of the creation and application of kinetic models for the deactivation of heterogeneous and liquid-phase catalysts under non-stationary conditions are considered. It is shown that high efficiency of catalytic technologies is ensured by regulation of hydrodynamic and thermal conditions of industrial processes of gasoline reforming, alkane dehydrogenation, alkylation of benzene with higher alkenes and catalytic dewaxing using kinetic models, which take into account catalyst deactivation.

The review is dedicated to the research and development work made in USSR and Russia in the area of catalytic processes with artificially created unsteady-state conditions. The paper discusses the reverse-flow operation of catalytic reactor, forced feed composition cycling and sorption enhancement of catalytic reactions. It is demonstrated that under proper choice of process concept and control strategy these approaches may result in creation of new technologies with improved efficiency, lower capital and operation costs, higher process stability under variation of process conditions and increased target product yield in thermodynamically limited reaction and complex reaction systems.