An analysis of the textural properties of activated carbons obtained from biomass via the LBET, NLDFT and QSDFT methods.

This article presents the unique research results of the comprehensive analysis of the porous structure of activated carbons obtained from biomass waste materials from the wood industry during activation in an air atmosphere. The porous structure was analysed on the basis of nitrogen and argon adsorption isotherms via complementary multi-method analysis, i.e.

Numerical Analysis of the Porous Structure of Activated Carbons Derived from Synthetic Polymers.

This paper presents original results from the unique analysis of the porous structure of activated carbons (ACs) produced through the chemical activation of polyethylene terephthalate (PET) and polyacrylonitrile (PAN), as well as from a physical mixture of both polymers. An advanced method of adsorbent surface analysis-more specifically, the new method of numerical clustering-based adsorption analysis regarding the surface heterogeneity, pore geometry and adsorption energy distribution parameters-allowed us to obtain information about the porous structure of the ACs from the synthetic polymers mentioned above. As the results showed, ACs obtained with PAN were characterised by a first adsorbed layer with the highest volume.

Effect of synthesis conditions on the porous texture of activated carbons obtained from Tara Rubber by FeCl activation.

This paper presents the results of an unique analysis of the influence of the mass ratio of activator FeCl to precursor and the temperature of the activation process on the formation of the porous structure of activated carbons obtained from Tara Rubber by FeCl activation. The study used the new numerical clustering based adsorption analysis method and the quenched solid density functional theory, taking into account, among other things, the heterogeneity of the analysed surface which is a new approach rarely used in the analysis of the porous structure of adsorbents. On the basis of the calculation results, it was concluded that the activated carbon with the most developed porous texture was obtained at a mass ratio (FeCl:Tara Rubber) of 2, at an activation process temperature of 800 °C.

Numerical analysis of the porous structure of spherical activated carbons obtained from ion-exchange resins.

This paper presents the results of an analysis of the porous structure of spherical activated carbons obtained from cation-exchange resin beads subjected to ion exchange prior to activation. The study investigated the effects of the type of cation exchange resin, the concentration of potassium cations in the resin beads and the temperature of the activation process on the adsorption properties of the resulting spherical activated carbons. The numerical clustering-based adsorption analysis method and the quenched solid density functional theory were used to analyse the porous structure of spherical activated carbons.

Analysis of the Influence of Activated Carbons' Production Conditions on the Porous Structure Formation on the Basis of Carbon Dioxide Adsorption Isotherms.

The results of a study of the impact of activation temperature and the mass ratio of the activator to the carbonised precursor on the porous structure of nitrogen-doped activated carbons obtained from lotus leaves by carbonisation and chemical activation with sodium amide (NaNH) are presented. The analyses were carried out via the new numerical clustering-based adsorption analysis, the Brunauer-Emmett-Teller, the Dubinin-Raduskevich, and the density functional theory methods applied to carbon dioxide adsorption isotherms. Carbon dioxide adsorption isotherms' analysis provided much more detailed and reliable information about the pore structure analysed.

Mathematical analysis of the effect of process conditions on the porous structure development of activated carbons derived from Pine cones.

This paper presents the results of a study on the influence of the degree of impregnation and activation temperature on the formation of the porous structure of activated carbons (ACs) obtained from Pine cones by the chemical activation process using potassium hydroxide as an activator. The advanced new numerical clustering based adsorption analysis (LBET) method, together with the implemented unique numerical procedure for the fast multivariant identification were applied to nitrogen and carbon dioxide adsorption isotherms determined for porous structure characterization of the ACs. Moreover, the Quenched Solid Density Functional Theory (QSDFT) method was chosen to determine pore size distributions.

Computer Analysis of the Porous Structure of Activated Carbons Derived from Various Biomass Materials by Chemical Activation.

In this study, the preparation of activated carbons from various materials of biomass origin by activation with potassium hydroxide and a comprehensive computer analysis of their porous structure and adsorption properties based on benzene (CH) adsorption isotherms were carried out. In particular, the influence of the mass ratio of the activator's dry mass to the char mass on the formation of the microporous structure of the obtained activated carbons was analysed. The summary of the analyses carried out based on benzene adsorption isotherms begged the conclusion that activated carbon with a maximum adsorption volume in the first adsorbed layer and homogeneous surface can be obtained from ebony wood at a mass ratio of the activator to the char of = 3.

Computer Analysis of the Effect of Activation Temperature on the Microporous Structure Development of Activated Carbon Derived from Common Polypody.

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody () via chemical activation with phosphoric acid (HPO) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation.

Analysis of the Effect of Conditions of Preparation of Nitrogen-Doped Activated Carbons Derived from Lotus Leaves by Activation with Sodium Amide on the Formation of Their Porous Structure.

This paper presents results of the analysis of the impact of activation temperature and mass ratio of activator to carbonized precursor on the porous structure of nitrogen-doped activated carbons derived from lotus leaves by carbonization and chemical activation with sodium amide NaNH. The analyses were carried out via the new numerical clustering-based adsorption analysis (LBET) method applied to nitrogen adsorption isotherms at -195.8 °C.

An Evaluation of the Reliability of the Results Obtained by the LBET, QSDFT, BET, and DR Methods for the Analysis of the Porous Structure of Activated Carbons.

This paper presents the results of an analysis of the impact of the activator to the product of carbonized materials mass ratio on the porous structure of activated carbons obtained from mahogany, ebony, and hornbeam wood by carbonization and chemical activation with potassium hydroxide. The analyses were carried out on nitrogen adsorption isotherms using the Brunauer-Emmett-Teller (BET), Dubinin-Radushkevitch (DR), and Quenched Solid Density Functional Theory (QSDFT) methods, as well as the numerical clustering-based adsorption analysis (LBET) method. The activated carbons with the best adsorption properties and homogeneous surfaces were obtained at a mass ratio of = 3.

An evaluation of the reliability of the characterization of the porous structure of activated carbons based on incomplete nitrogen adsorption isotherms.

The paper presents the results of research devoted to reliability evaluation of the analysis of results of the porous structure of activated carbons based on incomplete nitrogen adsorption isotherms using the BET, t-plot, and NLDFT methods, as well as the LBET method comprising the unique numerical fast multivariant procedure of adsorption system identification. The research involved the application of the nitrogen adsorption isotherms obtained for five samples of activated carbons produced from waste materials of organic origin by way of chemical activation with potassium hydroxide, sodium hydroxide, and potassium carbonate with the use of microwave heating. The analyses performed pointed to a good correlation between the results obtained using the BET, t-plot, NLDFT, and LBET methods.

Numerical studies of the effects of process conditions on the development of the porous structure of adsorbents prepared by chemical activation of lignin with alkali hydroxides.

This paper presents the results of the application of the advanced LBET and QSDFT methods compared to the BET and DR approach to the comprehensive analysis of the porous structure of activated carbons obtained by chemical activation of demineralised Kraft lignin with potassium and sodium hydroxides. Based on the analysis of nitrogen adsorption isotherms, the influence of the preparation process conditions on the porous structure formation was investigated. Particularly, the impact of the type of activating agent, the activation temperature, the hydroxide to lignin mass ratio, and the flow rate of inert gas on the porous structure formation was assessed.

Use of fast multivariant identification of the parameters of adsorption systems to study the impact of activating agent on microporous structure formation during activation.

The possibility of using fast multivariant identification of adsorption system parameters to evaluate the influence of the activation conditions on the microporous structure of carbonaceous adsorbents was examined. The fitted models used in the procedure are based on a unique approach to the modeling of adsorption processes, which is a significant development of the conventional BET approach. This takes into account the occurrence of branched clusters and surface heterogeneity.

Computer analysis of the microporous structure of activated carbon fibres using the fast multivariant identification procedure of adsorption system parameters.

The paper presents the results of the research on possible employment of the new fast multivariant identification procedure of adsorption system parameters as a tool for analysis of the microporous structure of activated carbon fibres. This research should provide information on what significant advantages can be drawn from applying the proposed new method of porous structures description in comparison to the classical approaches, as well as show how the results obtained using this method should be interpreted and what calculation results and additional information will be obtained from analysing the adsorption isotherms using a more sophisticated tool as compared to the classical models. Particularly, in presented method it is possible to easily acquire not only information regarding the values of the obtained structure parameters, but also, more importantly, precise information on the reliability of these parameter calculations.

Computer analyses of new numerical methods for the description of adsorption process and the reliability of identification of microporous structure parameters.

The aim of this work was the computer analysis of numerical properties of the original mathematical method of the description of adsorption process and the reliability of the identification of structure parameters. The method is based on the theory of multilayer adsorption, the derivation and further theoretical discussion of which was presented in the author's earlier works. The following tasks were given special attention in this paper: the influence of the assumed structure parameters, the influence of the high-pressure section of adsorption isotherms and the influence of the number of simultaneously fitted adsorption isotherms on the quality of identification and the errors of microporous structure parameters.

Numerical analysis of nitrogen adsorption isotherms on active carbons by an employment of the new LBET class models.

The reported research concerns properties of the new LBET class models designed to describe the heterogeneous adsorption on microporous carbonaceous materials. In particular, the new adsorption models were used for the analysis of the microporous structure of two active carbons on the basis of nitrogen adsorption isotherms. This paper gives more information on the properties of the proposed identification technique.

Computer analysis of microporous structure by employing the LBET class models with various variants of the adsorption energy distribution in comparison to the classical equations.

The paper presents a properties study of the new LBET class models for heterogeneous multilayer adsorption and its applicability to analysis of microporous carbonaceous adsorbents in comparison to the selected classical equations. This paper shows that the LBET formulas give a good insight into the pore size distribution and dominant pore shape. Moreover, they provide more reliable evaluation of material surface area than the popular classical equations.

Computer modeling and analysis of heterogeneous structures of microporous carbonaceous materials.

The aim of this work was to study the problems connected with computer modeling and analysis of heterogeneous structures of microporous carbonaceous materials. The research was focused on the numerical properties of original mathematical models for heterogeneous multilayer adsorption on microporous carbonaceous materials presented in our earlier papers and their applicability to examination of real microporous materials. These models are aimed at drawing information on pore structure and capacity on the basis of adsorption isotherms of small molecule adsorbates.