- Email: [email protected]
CALS-model of innovative technology for plasmachemical synthesis of nanopowders
20th European Symposium on Computer Aided Process Engineering – ESCAPE20 S. Pierucci and G. Buzzi Ferraris (Editors) © 2010 Elsevier B.V. All rights reserved.
CALS-model of innovative technology for plasmachemical synthesis of nanopowders A. Bessarabov,a A. Kvasyuk,a M. Ivanov,b N. Menshutinac a
The State Scientific-Research Institute of Chemical Reagents and High Purity Chemical Substances (IREA); Bogorodsky Val, 3, 107076, Moscow, Russia; E-mail: [email protected] b LOHR PLASMA, 29 rue du 14 Juillet, 67980 Hangenbieten, France; E-mail: [email protected] c Mendeleev University of Chemical Technology of Russia (MUCTR); Miusskaya square, 9, 125047, Moscow, Russia; E-mail: [email protected]
Abstract Information model of plasmochemical processes for synthesis of nanodispersed materials was developed on the basis of the CALS concept for the example of ultrapure compounds of tin, iron, silicon, titan, tungsten. Keywords: CALS, plasmachemistry, nanopowders, oxides, thermodynamic modelling.
1. Introduction In the last years, a special interest was generated by some nanopowders which are used in production of ceramic products, such as: tungsten carbide, tantalum, niobium, hafnium, molybdenum, silicon; silicon nitride, titanium nitride, aluminium nitride; silicon oxide, ferric oxide, aluminium oxide, zirconium oxide, titanium oxide and tin oxide. In our works special attention has been given to producing of oxide nanopowders of high purity.
2. CALS-project of universal plasmachemical apparatus To obtain a nanodisperse oxide of high purity the universal plasmachemical apparatus [1] was developed, which allows applying not only initial hardphase product by means of powder feeder, but liquid-phase reagents with the help of special sprayer. Universality of the plant allows obtaining nanodisperse oxide of metals of 2nd, 3rd and 4th group of the periodic system. Depending on amount of the parent material, plasmaformation gas flow and power insertion it is possible to obtain nanopowders of different dimension series. Development of the plasmachemical process was carried out in the context of the most current and perspective system of computer support – CALS-technology (Continuous Acquisition and Life cycle Support). Within design CALS-project a typical scheme was created (protocol of application) - «Initial data for designing» (fig. 1). Design electronic description according to STEP standard (fig. 1) contains the structure and variants of item configuration, geometrical models and drawings, properties and features of components. At the element of this scheme universal plasmachemical apparatus is shown allows to transfer to reactor (Fig. 1-a) not only the initial solid product by means of powder feeder, but the liquid reagents (chlorides and alchoxides) with a special sprayer (Fig. 1-b).
A. Bessarabov et al.
Fig. 1. Element of design CALS-project of plasmachemical apparatus for synthesis of nanomaterials (ɚ – reactor, b – sprayer, c – filter).
For this CALS-project of apparatus (Fig. 1) includes metering device for the transfer of initial materials powders, pulverizer for transfer of plasma-creating gas, filter for the product recovery (Fig. 1-c) and plasma torch. Apparatus universality allows obtaining nanodisperse compounds of tin, iron, silicon, titan, tungsten on it.
3. Regulation of nanopowders dispersity To the work and CALS-project researches, dealing with influence for nanodispersity of two parametrical complexes: aggregate condition of initial substance; ratio of speed pressures of plasma stream (PS) and stream of input gas (SIG) were included. Research of influence of aggregate condition was carried out for plasmachemical synthesis of nanopowders of silicon oxide (required granulated content: d = 10 nm). To the proper subcategory of information CALS-project the table of obtained results (Fig. 2-ɚ) was included. It is shown that for obtaining of required granulated content when using of initial substance (tetraethoxysilane – TEOS) ratio of SIG/PS is enough to 1. When input through sprayer of liquid TEOS ratio of SIG/PS equal to 12 is required. When input through feeder of quartz powder (d0 = 10 mcm) for obtaining of nanodisperse silicon oxide (10 nm) high ratio of SIG/PS equal to 50 is required. In CALS-project researches of influence for dispersity of final product of ratio of SIG/PS (Fig. 2-b) are shown. Quartz powder was used as initial product (d0= 10 mcm). Ratio of SIG/PS (E) varied from 20 till 50.
CALS-model of innovative technology for plasmachemical synthesis of nanopowders
Fig. 2. Element of CALS-project «Modeling of nanopowders dispersity» (influence on dispersity: ɚ – aggregate condition; b - ratio of SIG/PS).
As the result there were nanopowders with the diameter from 60 till 10 nm. This relation is approximated by the next exponential relation: ln(d) = a0 + a1E. Linear equation of correlation of ratio of SIG/PS and input power (W) also included to the model: W = W0 + b1E. Application in the CALS-project of methods of computer modeling and forecasting allow to create optimum flexible structure of high technology plasmachemical production and to provide full post sell support, including the documentation in electronic form.
4. Thermodynamic modeling Section no. 11 (mathematical description of the process) of the CALS project (Fig. 1) presents the results obtained in simulating the plasmachemical synthesis. Analysis of chemical and heat-and-mass exchange processes at elevated temperatures leads to severe difficulties already in the stage of formulation of the simulation problem. It is appropriate to use thermodynamic simulation methods as a first approximation. These methods presume that, in the processes under consideration, the working body forms a conditionally closed, isolated system in which a local thermodynamic equilibrium (LTE) is attained. In this approximation, the state of the system is only determined by the content of chemical elements in the system and by values of two parameters of state. The use of the thermodynamic equilibrium approximation is justified by the high concentration of energy in the volumes under consideration and by the resulting high rates of conversion processes, which instantaneously bring the system in the LTE state. A calculation of equilibrium for isolated multicomponent thermodynamic systems can be reduced to a problem of determination of a state with the minimum entropy. Therefore, to compose the sought-for system of equations, it is necessary to find an analytical relationship between the entropy of a unit mass of the working body and the thermodynamic parameters determining its composition, properties, and existence conditions.
A. Bessarabov et al.
Fig. 3. Screen form of the results of thermodynamic simulation of the plasmachemical synthesis.
A thermodynamic calculation of the equilibrium states of the system is performed in a wide range of basic parameters of the plasmachemical process: starting component ratios, temperatures, and pressures (Fig. 3). A thermodynamic simulation makes it possible to choose the synthesis conditions, analyze the environmental safety of the production process, and assess the mechanism of thermal dissociation of the starting compounds.
5. Computer quality management The system of a computer quality management is developed for a choice and the analysis of initial reagents and target products of plasmachemical synthesis (Fig. 4). The system has hierarchical structure of databases. Three basic information categories are allocated: «Analyzed substance»; «Analysis procedure» and «Output documentation» [2]. The developed information structure allows choosing optimum methods of the analytical control for as much as possible exact definition of qualitative characteristics of analyzed products. On the basis of information model the program complex of the CALS-project of analytical monitoring is developed. The program interface is performed taking into account an optimality of work of the user. Special procedures and the screen forms including a complex of modern elements of representation of the information and interaction with the user are developed for each stage of functioning of system. For assortment of initial reagents considered by us and target products of plasmachemical synthesis the following inorganic clusters are entered into the first category (Fig. 4): «alchoxides» (tetraethoxysilane, tetrabuthoxytitan); «oxides» (oxides of silicon, titan, tin, iron, and tungsten); «salts» (tungsten carbide).
CALS-model of innovative technology for plasmachemical synthesis of nanopowders
Fig. 4. Element of CALS-project CQM-system in category «Analyzed substance» (a – SiɈ2 high purity «HP 7-5»; b – SiɈ2 «HP 12-4»; c – tetraethoxysilane «HP 11-5»).
The chosen structure of classification of high purity nanomaterials corresponds to the applied All-Russian qualifier of standards (ARQS), a part of Uniform system of classification and coding of the technical and economic and social information (USCC) of the Russian Federation. The qualifier is harmonized with the International qualifier of standards (IQS) and the Interstate qualifier of standards.
6. Conclusions Implementation of CALS technologies and modern computerized quality management systems in development of science-intensive plasmachemical processes raises the productivity and diminishes the expenditure of time and material resources. This is achieved by simplified access to information, reorganization of the working activities (without change of the tasks to be accomplished), computerization of the working environment, and significant improvement of relationships between partner designers.
7. Acknowledgements This work was partly supported by the European Commission in the context of the Project ECOPHOS (Contract No INCO-CT-2005-013359).
References [1] Ⱥ.Ɇ. Bessarabov, Ⱥ.N. Ponomarenko, M.Ya. Ivanov, 2007, Information CALS-technologies (ISO-10303 STEP) in development of plasmachemical processes of obtaining of ultradisperse oxides of special pure, Journal of applied chemistry., Vol. 80, No. 1, p. 15-19. [2] A.M. Bessarabov, O.A. Zhdanovich, A.M. Yaroshenko, G.E. Zaikov, 2007, Development of an analytical quality control system of high-purity chemical substances on the CALS concept basis, Oxidation Communications, Vol. 30, No. 1, p. 206-214.
CALS-model of innovative technology for plasmachemical synthesis of nanopowders A. Bessarabov,a A. Kvasyuk,a M. Ivanov,b N. Menshutinac a
The State Scientific-Research Institute of Chemical Reagents and High Purity Chemical Substances (IREA); Bogorodsky Val, 3, 107076, Moscow, Russia; E-mail: [email protected] b LOHR PLASMA, 29 rue du 14 Juillet, 67980 Hangenbieten, France; E-mail: [email protected] c Mendeleev University of Chemical Technology of Russia (MUCTR); Miusskaya square, 9, 125047, Moscow, Russia; E-mail: [email protected]
Abstract Information model of plasmochemical processes for synthesis of nanodispersed materials was developed on the basis of the CALS concept for the example of ultrapure compounds of tin, iron, silicon, titan, tungsten. Keywords: CALS, plasmachemistry, nanopowders, oxides, thermodynamic modelling.
1. Introduction In the last years, a special interest was generated by some nanopowders which are used in production of ceramic products, such as: tungsten carbide, tantalum, niobium, hafnium, molybdenum, silicon; silicon nitride, titanium nitride, aluminium nitride; silicon oxide, ferric oxide, aluminium oxide, zirconium oxide, titanium oxide and tin oxide. In our works special attention has been given to producing of oxide nanopowders of high purity.
2. CALS-project of universal plasmachemical apparatus To obtain a nanodisperse oxide of high purity the universal plasmachemical apparatus [1] was developed, which allows applying not only initial hardphase product by means of powder feeder, but liquid-phase reagents with the help of special sprayer. Universality of the plant allows obtaining nanodisperse oxide of metals of 2nd, 3rd and 4th group of the periodic system. Depending on amount of the parent material, plasmaformation gas flow and power insertion it is possible to obtain nanopowders of different dimension series. Development of the plasmachemical process was carried out in the context of the most current and perspective system of computer support – CALS-technology (Continuous Acquisition and Life cycle Support). Within design CALS-project a typical scheme was created (protocol of application) - «Initial data for designing» (fig. 1). Design electronic description according to STEP standard (fig. 1) contains the structure and variants of item configuration, geometrical models and drawings, properties and features of components. At the element of this scheme universal plasmachemical apparatus is shown allows to transfer to reactor (Fig. 1-a) not only the initial solid product by means of powder feeder, but the liquid reagents (chlorides and alchoxides) with a special sprayer (Fig. 1-b).
A. Bessarabov et al.
Fig. 1. Element of design CALS-project of plasmachemical apparatus for synthesis of nanomaterials (ɚ – reactor, b – sprayer, c – filter).
For this CALS-project of apparatus (Fig. 1) includes metering device for the transfer of initial materials powders, pulverizer for transfer of plasma-creating gas, filter for the product recovery (Fig. 1-c) and plasma torch. Apparatus universality allows obtaining nanodisperse compounds of tin, iron, silicon, titan, tungsten on it.
3. Regulation of nanopowders dispersity To the work and CALS-project researches, dealing with influence for nanodispersity of two parametrical complexes: aggregate condition of initial substance; ratio of speed pressures of plasma stream (PS) and stream of input gas (SIG) were included. Research of influence of aggregate condition was carried out for plasmachemical synthesis of nanopowders of silicon oxide (required granulated content: d = 10 nm). To the proper subcategory of information CALS-project the table of obtained results (Fig. 2-ɚ) was included. It is shown that for obtaining of required granulated content when using of initial substance (tetraethoxysilane – TEOS) ratio of SIG/PS is enough to 1. When input through sprayer of liquid TEOS ratio of SIG/PS equal to 12 is required. When input through feeder of quartz powder (d0 = 10 mcm) for obtaining of nanodisperse silicon oxide (10 nm) high ratio of SIG/PS equal to 50 is required. In CALS-project researches of influence for dispersity of final product of ratio of SIG/PS (Fig. 2-b) are shown. Quartz powder was used as initial product (d0= 10 mcm). Ratio of SIG/PS (E) varied from 20 till 50.
CALS-model of innovative technology for plasmachemical synthesis of nanopowders
Fig. 2. Element of CALS-project «Modeling of nanopowders dispersity» (influence on dispersity: ɚ – aggregate condition; b - ratio of SIG/PS).
As the result there were nanopowders with the diameter from 60 till 10 nm. This relation is approximated by the next exponential relation: ln(d) = a0 + a1E. Linear equation of correlation of ratio of SIG/PS and input power (W) also included to the model: W = W0 + b1E. Application in the CALS-project of methods of computer modeling and forecasting allow to create optimum flexible structure of high technology plasmachemical production and to provide full post sell support, including the documentation in electronic form.
4. Thermodynamic modeling Section no. 11 (mathematical description of the process) of the CALS project (Fig. 1) presents the results obtained in simulating the plasmachemical synthesis. Analysis of chemical and heat-and-mass exchange processes at elevated temperatures leads to severe difficulties already in the stage of formulation of the simulation problem. It is appropriate to use thermodynamic simulation methods as a first approximation. These methods presume that, in the processes under consideration, the working body forms a conditionally closed, isolated system in which a local thermodynamic equilibrium (LTE) is attained. In this approximation, the state of the system is only determined by the content of chemical elements in the system and by values of two parameters of state. The use of the thermodynamic equilibrium approximation is justified by the high concentration of energy in the volumes under consideration and by the resulting high rates of conversion processes, which instantaneously bring the system in the LTE state. A calculation of equilibrium for isolated multicomponent thermodynamic systems can be reduced to a problem of determination of a state with the minimum entropy. Therefore, to compose the sought-for system of equations, it is necessary to find an analytical relationship between the entropy of a unit mass of the working body and the thermodynamic parameters determining its composition, properties, and existence conditions.
A. Bessarabov et al.
Fig. 3. Screen form of the results of thermodynamic simulation of the plasmachemical synthesis.
A thermodynamic calculation of the equilibrium states of the system is performed in a wide range of basic parameters of the plasmachemical process: starting component ratios, temperatures, and pressures (Fig. 3). A thermodynamic simulation makes it possible to choose the synthesis conditions, analyze the environmental safety of the production process, and assess the mechanism of thermal dissociation of the starting compounds.
5. Computer quality management The system of a computer quality management is developed for a choice and the analysis of initial reagents and target products of plasmachemical synthesis (Fig. 4). The system has hierarchical structure of databases. Three basic information categories are allocated: «Analyzed substance»; «Analysis procedure» and «Output documentation» [2]. The developed information structure allows choosing optimum methods of the analytical control for as much as possible exact definition of qualitative characteristics of analyzed products. On the basis of information model the program complex of the CALS-project of analytical monitoring is developed. The program interface is performed taking into account an optimality of work of the user. Special procedures and the screen forms including a complex of modern elements of representation of the information and interaction with the user are developed for each stage of functioning of system. For assortment of initial reagents considered by us and target products of plasmachemical synthesis the following inorganic clusters are entered into the first category (Fig. 4): «alchoxides» (tetraethoxysilane, tetrabuthoxytitan); «oxides» (oxides of silicon, titan, tin, iron, and tungsten); «salts» (tungsten carbide).
CALS-model of innovative technology for plasmachemical synthesis of nanopowders
Fig. 4. Element of CALS-project CQM-system in category «Analyzed substance» (a – SiɈ2 high purity «HP 7-5»; b – SiɈ2 «HP 12-4»; c – tetraethoxysilane «HP 11-5»).
The chosen structure of classification of high purity nanomaterials corresponds to the applied All-Russian qualifier of standards (ARQS), a part of Uniform system of classification and coding of the technical and economic and social information (USCC) of the Russian Federation. The qualifier is harmonized with the International qualifier of standards (IQS) and the Interstate qualifier of standards.
6. Conclusions Implementation of CALS technologies and modern computerized quality management systems in development of science-intensive plasmachemical processes raises the productivity and diminishes the expenditure of time and material resources. This is achieved by simplified access to information, reorganization of the working activities (without change of the tasks to be accomplished), computerization of the working environment, and significant improvement of relationships between partner designers.
7. Acknowledgements This work was partly supported by the European Commission in the context of the Project ECOPHOS (Contract No INCO-CT-2005-013359).
References [1] Ⱥ.Ɇ. Bessarabov, Ⱥ.N. Ponomarenko, M.Ya. Ivanov, 2007, Information CALS-technologies (ISO-10303 STEP) in development of plasmachemical processes of obtaining of ultradisperse oxides of special pure, Journal of applied chemistry., Vol. 80, No. 1, p. 15-19. [2] A.M. Bessarabov, O.A. Zhdanovich, A.M. Yaroshenko, G.E. Zaikov, 2007, Development of an analytical quality control system of high-purity chemical substances on the CALS concept basis, Oxidation Communications, Vol. 30, No. 1, p. 206-214.