Department of Chemical thermodynamics and kinetics
Critical phenomena and processes in multicomponent heterogeneous systems with chemical interaction
Head of Scientific Group
Maria A. Toikka
PhD, Associate Professor
Maya A. Trofimova
PhD, Associate Professor
Artemiy A. Samarov
PhD, Associate Professor
Alexandra D. Golikova
PhD, Assistant Professor
- Alexander A. Smirnov, postgraduate student;
- Georgii Kh. Misikov, student;
- Konstantin A. Zolotovskiy, student.
Experimental studies of critical phenomena in systems with chemical interaction of components. Kinetics of chemical reactions in the near-critical region of liquid-phase systems. Thermodynamic and structural features of multicomponent critical phases during an equilibrium and non-equilibrium chemical reaction (critical surfaces and hypersurfaces). Thermodynamic and model calculations. Thermochemical studies (calorimeters of mixing, titration, differential scanning calorimetry). Deep eutectic solvents. Additional (applied) profile of activity: research of processes associated with the production of biofuels.
The journals in which the results of the scientific group are published:
In the first half of 2022, the scientific team obtained many new results as part of the continuation of the experimental study of reaction systems containing biodiesel, including deep eutectic solvents (DES). The results of studying the phase behavior of the system oleic acid – methyl alcohol – methyl oleate – water  indicate that the heterogeneous region occupies almost the entire volume of the concentration tetrahedron (about 85% of its volume). Comparative analysis of the experimentally obtained data for binary methyl oleate - water and ternary methyl alcohol - methyl oleate - water mixtures with literature compositions showed that the results are in good agreement with each other: the solubility of these systems increases with increasing temperature of the experiment. Modeling of the phase behavior of the system under study was carried out using thermodynamic models: NRTL and UNIFAC. It was found that the results of calculations using the NRTL model are in good agreement with the experimental data (the standard deviation does not exceed 0.42%). The compositions of the coexisting liquid phases calculated using the UNIFAC model are in good agreement with the experimental values. Deep eutectic solvents (DES)  formed by choline chloride and ethylene glycol or propylene glycol were used to separate model azeotropic mixtures containing ethyl, n-propyl, and n-butyl alcohols and the corresponding esters (acetates). For this, experimental data on the compositions of coexisting liquid phases at temperatures of 293.15 K and 313.15 K and atmospheric pressure were obtained. Equilibrium liquid-liquid compositions were determined using NMR spectroscopy. The liquid density and dynamic viscosity of the studied deep eutectic solvents are measured in the temperature range from 293.15 K to 323.15 K at atmospheric pressure. The separation efficiency of DES was characterized by partition coefficients and selectivity values for alcohols. The selectivity values in systems containing alcohols and esters were compared with other deep eutectic solvents consisting of choline chloride and various hydrogen bond donors (malonic acid, glutaric acid, glycerol, and urea). The highest selectivity of alcohol recovery among the studied DES was shown by DES based on choline chloride and ethylene glycol. The highest efficiency of this solvent in separation is achieved in the system n-butyl alcohol - n-butyl acetate - DES.
Without exception, all the results obtained by the scientific group in the first half of 2022 are necessary for the development of an experimental database on the physicochemical properties of systems containing biodiesel fuel components, as well as for the analysis of the possibility of using deep eutectic solvents (DES) in the synthesis and purification of biodiesel based on the evaluation of the effectiveness of various DES, and to search for fundamental thermodynamic and kinetic patterns of the behavior of the studied systems.
- Maria Toikka, Petr Kuzmenko, Artemiy Samarov, Maya Trofimova. Phase behavior of the oleic acid – methanol – methyl oleate – water mixture as a promising model system for biodiesel production: Brief data review and new results at 303.15 K and atmospheric pressure. Fuel 319 (2022) 123730. Doi: 10.1016/j.fuel.2022.123730. Q1
- Artemiy Samarov, Igor Prikhodko, Dmitrii Liubichev, and Maria Toikka. Liquid−Liquid Equilibrium of Alcohol−Ester Systems with Deep Eutectic Solvents Based on Choline Chloride and Alkanediols (Ethylene Glycol or Propylene Glycol) // Journal of Chemical & Engineering Data 2022 67 (3), 707-716. DOI: 10.1021/acs.jced.1c00913. Q1
The development of energy and resource-saving environmentally friendly technologies is one of the main trends in the innovative development of the Russian Federation. Today one of the leading places among alternative energy sources is occupied by biodiesel fuel. Scientific problem, which is being solved by a scientific group led by Toikka M.A. in the direction of "Chemistry and Materials Science", is to search, develop, develop and improve new experimental and theoretical methods for studying and analyzing phase equilibria of reaction systems containing biodiesel fuel and deep eutectic solvents (DES). Specific scientific tasks are to obtain a set of experimental data on the phase equilibrium of multicomponent heterogeneous systems, including components of biodiesel fuel, as well as deep eutectic solvents that act as extracting solvents in the processes of synthesis and purification of biodiesel, namely: experimental data on the kinetics of reactions in a heterogeneous medium (for the same systems); evaluation of the effectiveness of the use of deep eutectic solvents for the purification of biodiesel fuel; thermodynamic analysis of the topological features of the phase diagrams of the state of complex reaction systems and the kinetics of reactions in a heterogeneous medium based on the obtained experimental data; development of methods for analyzing and modeling processes in the systems under consideration using the apparatus of nonequilibrium thermodynamics; generalization of the results of the project for a wide range of physical and chemical systems. Experimental studies also cover a number of model systems involving carboxylic acid esters with a smaller number of carbon atoms, in contrast to fatty acid esters. In the course of 2021, the team of the scientific group obtained new experimental data on phase equilibrium, primarily for model systems with the participation of carboxylic acid esters and mixtures, including biodiesel synthesis products. Thus, new experimental data on liquid-liquid equilibrium and solubility were obtained for a system containing acetic acid, n-butyl alcohol, n-butyl acetate, and water at 328.15 K and 101.3 kPa . It is known that the addition of butyl acetate to biodiesel fuel improves the characteristics of the latter: the fluidity of the fuel increases, as well as the safety of fuel use due to the high flash point of butyl acetate. One of the most important directions in the study of the system acetic acid - n-amyl alcohol - n-amyl acetate - water is the study of solubility and phase equilibria for organizing the industrial process of reactive distillation of n-amyl acetate. This coupled process combines the reaction and separation steps that are increasingly being used in fuel synthesis, including biodiesel. New experimental data on the solubility and liquid-liquid equilibrium in the quaternary system acetic acid – n-amyl alcohol – n-amyl acetate – water and its ternary subsystems acetic acid – n-amyl alcohol – water, acetic acid - n-amyl acetate – water and n-amyl alcohol – n-amyl acetate – water, including binary mixtures (n-amyl alcohol – water and n-amyl acetate – water) at 293.15 K, 303.15 K, 313.15 K, 323.15 K and atmospheric pressure [2, 3]. The results of studying the chemical equilibrium for this system at a temperature of 318.15 K are presented in . It has been established that both homogeneous compositions and the region of heterogeneous chemically equilibrium mixtures belong to the chemical equilibrium surfaces. The liquid–liquid phase equilibrium in ethanol–n-propyl acetate and n-propanol–ethyl acetate systems with deep eutectic solvents (DES) was also studied at temperatures of 293.15 K and 313.15 K and atmospheric pressure. Choline chloride–glycerol and choline chloride–urea DES were studied in a 1:2 molar ratio. The experimental data were checked for internal consistency using the Othmer–Tobias equation. Based on the obtained data, distribution coefficients and selectivity values were calculated. The effect of alcohol and ether on the position of the phase equilibrium region has been established. The results of data processing using the NRTL model equations reflect a high level of correlation – the standard deviation does not exceed 0.96% . The synthesis of fatty acid esters (biodiesel) from sunflower oil and methanol with a KOH catalyst was carried out. To assess the effect of the composition of DES on the efficiency of extraction, mixtures of biodiesel fuel with esters of methyl acetate, methyl butyrate, methyl propionate, ethyl acetate, ethyl butyrate and ethyl propionate with DES were studied with a ratio of choline chloride: glycerol = 1:2, 1:1.8, 1:1.6, 1:1.4 . The effect of the DES composition on the viscosity and density of the extractant is considered. The main methods for analyzing reaction compositions are gas chromatography (Crystal 5000.2 and Shimadzu GC-2010PLUS) and nuclear magnetic resonance (Bruker 500 MHz Avance III) for identifying mixtures of complex composition. Experimental studies of phase equilibria were carried out on facilities specially designed for this scientific research. In general, according to the results of 2021, 5 [1-5] articles on the topics of the scientific group were published in journals indexed in the Web of Science Core Collection and Scopus databases, including 3 Q1 articles [1, 3, 4]. The results are presented in abstracts of reports at 9 international and 3 National conferences.
The scientific group implements 2 grants from the Russian Science Foundation and 1 grant from the President of the Russian Federation for young scientists. The work of the team was supported by the Government of St. Petersburg for young PhD of science. In 2021, 2 undergraduates and 2 bachelors successfully passed the defended their graduation theses.
- Alexander Smirnov, Artemiy Samarov, Maria Toikka. Liquid−Liquid Equilibrium, Solubility, and Critical States in an Acetic Acid−n Butyl Alcohol−n Butyl Acetate−Water System at 328.15 K and 101.3 kPa: Topology of Phase Diagrams and NRTL Modeling. J. Chem. Eng. Data 2021, (Publication Date: February 26) 66 (3), 2021, P. 1466-1474. DOI: 10.1021/acs.jced.0c01066. Q1
- Maya Trofimova, Georgii Misikov, Artemiy Samarov, Igor Prikhodko and Maria Toikka. Solubility in the system acetic acid – n-amyl alcohol – n-amyl acetate – water at 293.15 K, 303.15 K, 313.15 K and 323.15 K and atmospheric pressure. The Journal of Chemical Thermodynamics 161 (2021) 106515 (accepted for publication 1 May 2021). DOI: 10.1016/j.jct.2021.106515.
- Misikov G., Toikka M. Samarov A., Toikka A. Phase equilibria liquid-liquid for ternary systems n-amyl alcohol – water – (acetic acid, n-amyl acetate), n-amyl acetate – water – acetic acid at 293.15 K, 303.15 K, 313.15 K and 323.15 K. Fluid Phase Equilibria, Vol. 552 (2021) 113265. DOI: 10.1016/j.fluid.2021.113265. Q1
- Alina Senina, Artemiy Samarov, Maria Toikka, Alexander Toikka. Chemical equilibria in the quaternary reactive mixtures and liquid phase splitting: a system with n-amyl acetate synthesis reaction at 318.15 K and 101.3 kPa. Journal of Molecular Liquids 345 (2022) 118246. DOI: 10.1016/j.molliq.2021.118246. Q1
- Samarov A.A., Toikka M.A., Toikka A.M. Phase Equilibria in Alcohol–Ester Systems with Deep Eutectic Solvents Based on Choline Chloride at 293.15 and 313.15 K. Theoretical Foundations of Chemical Engineering, 2021, Vol. 55, No. 2, pp. 290–300. DOI: 10.31857/S004035712102010X
The development of an experimental base on the physicochemical properties of biofuel systems, methods of thermodynamic modeling of complex systems, which should include reaction mixtures based on biofuel production reagents, are an absolute basis for the development of energy- and resource-saving environmentally friendly technologies. One of the defining aspects of the development of the production and use of liquid biofuel — the object of this study — remains the rational use of biological resources, the implementation of processes and waste-free production.
In 2020, a research group conducted research on biofuel systems in which combined reaction-mass transfer processes take place. The importance of thermodynamic research is undeniable for expanding the fundamental basis in biofuel research. Specific experimental objects of research are model biofuel systems containing mixtures of carboxylic acids (ethane, propane) and alcohols (ethanol, propanol, butanol). The main studied physicochemical properties are chemical and phase equilibria, as well as excess enthalpies. The resulting array of fundamental physical and chemical results is included in the main databases of physical and chemical data (NIST, etc.). In theoretical terms, the analysis of the results of the project is associated with the use of the apparatus of nonequilibrium thermodynamics to characterize chemical processes.
The scientific group has published seven articles in international journals indexed in WOS / Scopus in 2020.
One of the images (top right), published in an article in the international journal Journal of Chemical & Engineering Data (IF 2.369), is featured on the cover of the May 2020 issue. The authors of the work are the staff of the Department of Chemical Thermodynamics and Kinetics of the Institute of Chemistry — Artemiy A. Samarov, Maya A. Trofimova, Maria A. Toikka and Alexander M. Toikka (DOI: 10.1021 / acs.jced.9b01205).
The research group implements one RFBR grant, two RSF grants and one RF President's scholarship for young scientists. In 2020, one PhD student was successfully defended.
The most significant publications of 2020:
- Alina Senina, Vladimir Margina, Alexandra Golikova, Nikita Tsvetov, Anna Sadaeva, Maria Toikka. Physico-chemical study of systems involving ethanol, promising for use as a biofuel // Fuel. Vol. 284 (2021) 119099. (Impact Factor Web of Science 2019 JCR Science Edition - 5.578; DOI: 10.1016 / j.fuel.2020.119099)
- Maria Toikka, Kristina Podryadova, Anastasia Kudryashova. Liquid-liquid equilibria, solubility and critical states in the systempropionic acid – 1-propanol –n-propyl propionate – water at 303.15 K // The Journal of Chemical Thermodynamics. Vol. 152 (2021) (online 12 August 2020) 106265. (Impact Factor Web of Science 2019 JCR Science Edition - 2.888; DOI: 10.3390 / sym12071142)
- Alexandra Pulyalina, Valeriia Rostovtseva, Iana Minich, Oleg Silyukov, Maria Toikka, Nataliia Saprykina, Galina Polotskaya. Specific Structure and Properties of Composite Membranes Based on the Torlon® (Polyamide-imide)/Layered Perovskite Oxide // Symmetry 2020, 12(7), 1142. (Impact Factor Web of Science 2019 JCR Science Edition - 2.645; DOI: 10.3390 / sym12071142)
- Nikita Tsvetov, Anna Sadaeva, Maria Toikka, Irina Zvereva, Alexander Toikka. Excess molar heat capacity for the binary system n-propyl alcohol plus water in the temperature range 278.15-358.15 K: new data and application for excess enthalpy calculation // Journal of Thermal Analysis and Calorimetry (on-line 5 April 2020) 2020. (Impact Factor Web of Science 2019 JCR Science Edition - 2.731; DOI: 10.1007 / s10973-020-09605-y)
- Artemiy Samarov, Maya Trofimova, Maria Toikka and Alexander Toikka. Experimental Data on Chemical Equilibrium in the System with Ethyl Formate Synthesis Reaction at 298.15 K // Journal of Chemical and Engineering Data, Available online 30 March 2020. (Impact Factor Web of Science 2019 JCR Science Edition - 2.369; DOI: 10.1021 / acs.jced.9b01205)
In 2019, fundamentally new results were obtained for the prospective use and development of biofuel systems technology, solving urgent problems of optimizing biofuel production in the direction of energy and resource conservation. An experimental study of the phase behavior of biofuel systems of the carboxylic acid - alcohol - corresponding ether - water type has been carried out in a wide range of temperatures and compositions of chemically reacting mixtures, as well as an analysis of new possibilities for theoretical thermodynamic-kinetic study of combined processes. Thermochemical experiments include studies of heats of mixing (excess enthalpies) and the heats of chemical reactions in biofuel systems.
Theoretical approaches and methods for solving problems in the field of thermodynamic theory of solutions are largely based on the results of the thermodynamic school of St. apparatus of nonequilibrium thermodynamics for the development of research methods for combined membrane processes, phase and chemical equilibria, as well as for the development of the phenomenological theory of chemical processes in general. The results of the work of the scientific group were highlighted in the media: the program "Good morning" on the TV channel "Petersburg" on January 28, 2019 "What is biofuel".
In 2019, the research group has published nine articles in international journals indexed in WOS / Scopus.
The research group implements two RFBR grants, two Russian Science Foundation grants and one RF President's scholarship for young scientists. The work of the team was supported by the Government of St. Petersburg for young candidates of sciences, including in the field of scientific and pedagogical activities. In 2019, 4 bachelors successfully defended their Diploma thesis.
The most significant publications of 2019:
- Maria Toikka, Alexey Sadaev, Artemiy Samarov. Liquid-liquid equilibria, solubility and critical states in the system propionic acid – n-butanol – n-butyl propionate – water at 293.15 K and atmospheric pressure // The Journal of Chemical Thermodynamics, Available online 17 September 2019. (Impact Factor Web of Science 2019 JCR Science Edition - 2.888; DOI: 10.1016 / j.jct.2019.105957)
- Maya Trofimova, Alexey Sadaev, Artemiy Samarov, Alexandra Golikova, Nikita Tsvetov, Maria Toikka, Alexander Toikka. Liquid-liquid equilibrium of acetic acid – ethanol – ethyl acetate – water quaternary system: Data review and new results at 323.15 K and 333.15 K // Fluid Phase Equilibria. Vol. 503 (1 January 2020) (on-line 14 September 2019). (Impact Factor Web of Science 2019 JCR Science Edition - 2.838; DOI: 10.1016 / j.fluid.2019.112321)
- Alexandra Golikova, Nikita Tsvetov, Artemiy Samarov, Maria Toikka, Irina Zvereva, Maya Trofimova, Alexander Toikka. Excess enthalpies and heat of esterification reaction in ethanol + acetic acid + ethyl acetate + water system at 313.15 K // Journal of Thermal Analysis and Calorimetry (on-line 20 June 2019). (Impact Factor Web of Science 2018 JCR Science Edition - 2.731; DOI: 10.1007 / s10973-019-08488-y)
- M.A. Toikka, A.A. Samarov, A.A. Sadaeva, A.A. Senina, O. L. Lobachev. Chemical equilibrium in the system propionic acid - ethyl alcohol - ethyl propionate - water and extraction processes with the participation of deep eutectic solvents // Fine chemical technologies. Volume 14 No. 1. 2019. S. 47-58. (Impact factor RSCI 2019 - 0.25; DOI: 10.32362 / 2410-6593-2019-14-1-47-58)
- Alexander Smirnov, Anna Sadaeva, Kristina Podryadova, Maria Toikka. Quaternary liquid-liquid equilibrium, solubility and critical states: Acetic acid - n-butanol - n-butyl acetate - water at 318.15 K and atmospheric pressure // Fluid Phase Equilibria. Vol. 493 (1 August 2019) P. 102-108. (Impact Factor Web of Science 2019 JCR Science Edition - 2.838; DOI: 10.1016 / j.fluid.2019.04.020)
- Toikka M., Sadaeva A., Samarov A., Toikka A. Solubility and critical surface in the system propionic acid–ethanol–ethyl propionate–water at 293.15, 303.15 and 313.15 K // Journal of Chemical Thermodynamics. Vol. 132. May 2019. P. 113-121. (Impact Factor Web of Science 2019 JCR Science Edition - 2.888; DOI: 10.1016 / j.jct.2018.12.026)
- Maya Trofimova, Alexey Sadaev, Artemiy Samarov, Maria Toikka, Alexander Toikka. Solubility, liquid-liquid equilibrium and critical states for the quaternary system formic acid – ethanol – ethyl formate – water at 298.15 K and 308.15 K // Fluid Phase Equilibria. Vol. 485 (April 2019) P. 111-119. (Impact Factor Web of Science 2019 JCR Science Edition - 2.838; DOI: 10.1016 / j.fluid.2018.12.024)
In 2018, work was continued on the study of reaction-mass transfer processes in multicomponent reaction stratified systems formed by biofuel components. A study of several model heterogeneous liquid-phase chemically reacting mixtures was carried out, including by calorimetric methods, which made it possible to establish new thermodynamic-kinetic regularities of the combined processes "reaction + phase transition". The element of novelty was the use of the apparatus of nonequilibrium thermodynamics.
The obtained experimental and theoretical data received the corresponding thermodynamic interpretation. In particular, a number of works provide new experimental data on phase and chemical equilibrium in systems with the participation of ethyl propionate, ethyl acetate, and amyl acetate. The extraction properties of deep eutectic solvents (DES) based on choline chloride and glycerol / urea have been studied. The information and service portal “Gazeta.ru” published a message about one of the following results: “Russian scientists have modeled the process of biofuel synthesis”.
In 2018, the research group published seven articles in international journals indexed in WOS / Scopus. Five articles — in journals of Q1 level. The group employs: 2 associate professors, 1 assistant, 1 junior researcher, 1 graduate student and 8 students.
The research group implements two RFBR grants, two Russian Science Foundation grants and two RF President's scholarships for young scientists. The work of the team was supported by the Government of St. Petersburg for young candidates of sciences, including in the field of scientific and pedagogical activities. In 2018, two bachelors successfully defended their Diploma thesis.
- M. Toikka, V. Vernadskaya, A. Samarov. Solubility, liquid-liquid equilibrium and critical states for quaternary system acetic acid – n-amyl alcohol – n-amyl acetate – water at 303.15 K and atmospheric pressure, Fluid Phase Equilibria. Vol. 471 (2018) P. 68–73. DOI: 10.1016/j.fluid.2018.05.009
- M. Toikka, D. Trofimova, A. Samarov. Liquid-liquid equilibrium and critical states for the quaternary system propionic acid–n-butanol–n-butyl propionate–water at 303.15 K, Fluid Phase Equilibria. Vol. 460 (25 March 2018) P. 17–22. DOI: 10.1016/j.fluid.2017.12.023
- A.A. Samarov, M.A. Smirnov, A.M. Toikka, I.V. Prikhodko, Study of Deep Eutectic Solvent on the Base Choline Chloride as Entrainer for the Separation Alcohol-Ester Systems, Journal of Chemical and Engineering Data. 2018. 63 (6). P. 1877–1884. DOI: 10.1021/acs.jced.7b00912