Properties of limestone related to SO2/SO3 reactivity were investigated. Limestone calcined under different conditions (temperature, time and with/without additives)
yield calcines of distinctly different physical structures. The amount of pores and the size of the pores formed during calcination
The main purpose of the present work was to gain a better understanding and more reliable explanation of the temperature regime
for gas desulphurization using Ca-based sorbents in atmospheric fluidized-bed combustors.
Pore size, surface area and pore volume of each calcine were determined by mercury porosimetry and BET methods. At higher
calcination temperature and during longer time, sintering became significant and the obtained calcine had a smaller internal
surface area and thereby the average pore radius increased. The additives such as NaCl also accelerated sintering thus increasing
the pore size. The measurements of porosity were supplemented by scanning electron microscopic observations employed for qualitative
description of the pore structure. SEM micrographs are presented.
Authors:D. Sternik, M. Błachnio, P. Staszczuk, G. Chądzyński, and E. Kowalska
properties (adsorption capacity, desorption energy distribution and pore-size
distribution functions) of nanomaterial surfaces from selected materials,
based on sorptometric and liquid thermodesorption measurements under quasi-equilibrium
conditions, are presented. The fractal dimensions of nanotubes using sorptometric
and AFM data have been evaluated.
Comparison of thermogravimetric
and other data provide new information about the adsorption and pore structure
of the studied materials. The fractal dimensions of nanomaterial surfaces
using sorptometry are in good agreement with those from AFM.
Specific surface area and pore size distribution are determined usually from adsorption isotherms at low temperatures using
nitrogen or noble gases. These are not absolute parameters and the measuring methods are fraught with serious difficulties.
General problems of sorption measurements and recent developments are discussed. To obtain information for practical purposes
these measurements need to be supplemented by investigations of the sorbate/sorbent system used in practice. Results of the
measurement of nitrogen and water vapour adsorption on different materials are compared.
Thermodesorption of benzene and water from alumina samples saturated in vacuum dessicator were studied under quasi-isothermal
conditions. The Q-TG and Q-DTG curves show multi-step mass losses associated with the evaporation of liquids from pores and
physisorbed liquid films from active sites with different energies. The isotherms of adsorption-desorption of nitrogen on
porous alumina samples were measured using sorptomatic method and pore size distribution functions have been calculated. The
correlation between porosity parameters and the volume of desorbed liquids is presented. A good agreement between above data
Authors:G. Romanos, V. Kasselouri, K. Beltsios, and N. Kanellopoulos
The aim of the present study was the pore structure characterization of porous glass derived from a leachable precursor. Two
independent techniques were applied on this purpose. The interpretation of the results obtained by these techniques, i.e.
thermoporometry and nitrogen porosimetry was indicative for their supplementary character in what concerns the calculation
of pore size distributions. The experimental work described in this study gives an example for the monitoring of the compositional
evolution of phase separating compact-glass precursors of porous glasses.
Authors:P. Staszczuk, D. Sternik, G. Chądzyński, E. Robens, and M. Błachnio
adsorption measured at 77 K was used to characterize the surface heterogeneity
of high-temperature superconductor surfaces. Properties relating to adsorption
and porosity of the solids (adsorption capacity, specific surface area, radii
and volume of the pores, pore-size distribution function) were determined
from nitrogen adsorption–desorption isotherms and atomic force microscopy
(AFM) for a series of oxide superconductors. It is shown that the adsorption
isotherms of all samples are S-shaped and belong to type II according to the
IUPAC classification. On the basis of the nitrogen adsorption isotherms and
AFM data, fractal dimensions were determined and correlations found with adsorption
and porosity parameters.
Authors:Tamás Földes, Gizella B. Árgyelán, Péter Bogner, Imre Repa, Balázs Kiss, and Kinga Hips
This paper summarizes the benefits of non-destructive core measurements by medical Computer Tomograph (CT) in integrated 3D reservoir characterization. A direct relationship exists between CT measurements and petrography, conventional petrophysical analysis and well logs. Based on CT measurements the internal structure of core samples, and the geometry of framework constituents, porosity type and pore size distribution, as well as fracturing, can be described. There is a close connection between distribution of the Hounsfield Unit of CT measurements and pore size distribution detected by conventional petrophysical analysis. Calculation of effective porosity from petroleum saturation experiments provides a new way to determine the porosity of the whole core sample. Beside the description of reservoir parameters, the results of CT measurements can be extended over the surrounding area of the well. By matching the cylinder maps of CT to FMI images and other well logs the original position of the core samples can be reconstructed. Applying high-tech CT measurements in 3D reservoir characterization and modeling of fluid migration significantly reduces the exploration and production risks.
Authors:Charu Dwivedi, Naina Raje, Manmohan Kumar, A. Reddy, and P. Bajaj
The present work describes the application of radiotracer technique for studying uptake of arsenic on titanium hydroxide,
commercial titanium dioxide (TiO2) powder (anatase) and synthesized mesoporous titania beads in acidic, neutral, and alkaline conditions. Sol–gel templating
method was used to prepare titania–polysaccharide composites, with different polymer contents. Mesoporous titania was obtained
by heat treatment of the composite beads in a controlled environment. The synthesis process was optimized, using thermogravimetry
analysis. X-ray diffraction patterns confirmed the formation of anatase pure phase titania (TiO2) at 700 °C in different environments, and scanning electron microscopy studies confirmed uniform pore size distribution.
The effect of surface area, polymer content and pH on uptake of arsenic(III) and (V) on the synthesized titania beads was
also investigated. Arsenic(V) was found to be retained quantitatively on the titania beads synthesized from 0.8% polymer content
titania–polymer composite precursor in neutral to alkaline conditions. Details of the results obtained are discussed.
The paper presents evaluation of energy distribution of n-octane and pore-size distribution functions on the alumina oxide surface (e.g. total heterogeneity) of on the basis one experimental
run. the Q-TG mass loss and derivative Q-DTG mass loss curves of n-octane thermodesorption from the alumina oxide sample were made using a hungarian derivatograph with an analyser equipped
with an automatic ultraslow procedure and a special crucible of maintaining the quasi-isothermal heating procedure to increase
the resolution of thermal analysis. a new theoretical and experimental procedure was developed for evaluation of distribution
functions of liquid preadsorbed on the mesoporous surface from special thermogravimetry. An example of the approach to quantitative
description of the energetic and structural heterogeneities of alumina oxide surface is given.
Authors:Ana Carla S. L. S. Coutinho, Solange A. Quintella, A. S. Araujo, Joana M. F. Barros, Anne M. G. Pedrosa, V. J. Fernandes Jr., and M. J. B. Souza
Nanoporous silica with narrow pore size distribution has attracted increasing attention as a novel material for separations and reactions involving large molecules. SBA-15 has been synthesized in an acidic medium using a triblock copolymer as template. In this work, the SBA-15 was synthesized by the hydrothermal treatment at 373 K for 48 h, of a gel with the following overall molar composition: 1.0TEOS:0.017P123:5.7HCl:193H2O, where TEOS is tetraethyl orthosilicate and P123 is poly(ethylene oxide, propylene oxide and 1,4-dioxane). The obtained material was characterized by thermogravimetry, X-ray diffraction, infrared spectroscopy and BET surface area. A kinetic study using the model free model was accomplished in the stage of decomposition of the template (P123). The obtained value of the apparent activation energy was ca. 131 kJ mol−1.