Methane Adsorption on Microporous Carbon Adsorbent Prepared from Thermochemically Activated Wood

Abstract— An EC-103 microporous carbon adsorbent was synthesized from wood using thermochemically activation with Н3РО4 as an activating agent. Methane adsorption on the EC-103 adsorbent was studied within the temperature range from 303 to 333 K and at pressures up to 40 MPa. The total volume of sorbing pores was 1.71 cm3/g. The maximum values of methane adsorption were obtained at the temperature of 303 K and pressure of 40 MPa. The differential molar isosteric heat of methane adsorption 14.5 mmol/g (23.2 wt %) was on the average of 12−14 kJ/mol. Methane adsorption on the EC-103 adsorbent was calculated based on the Dubinin theory of volume filling of micropores (TVFM). It was shown that the Dubinin-Radushkevich equation and basic TVFM pattern provided the best description of experimental data on methane adsorption with the use of only the standard structural and energy characteristics of the adsorbent.

CHANGE OF THERMODYNAMIC CHARACTERISTICS OF THE CARBON ADSORBENT FAS-3 AT ADSORPTION OF BENZENE

Впервые проведены комплексные исследования адсорбционной деформации - сорбострикции микропористого углеродного адсорбента ФАС-3 при адсорбции паров бензола из потока газа-носителя - азота в неравновесных условиях. Изучены изотермы адсорбции паров бензола микропористым углеродным адсорбентом ФАС-3 в равновесных условиях. Были представлены формулы и проведены расчеты изменений энтропии и внутренней энергии адсорбента в адсорбционном процессе. For the first time, complex studies were carried out on adsorption deformation - sorbostriction of the microporous carbon adsorbent FAS-3 at adsorption of benzene vapors from the flow of carrier gas - nitrogen in non-equilibrium conditions. Adsorption isotherms of benzene vapors by the microporous carbon adsorbent FAS-3 under equilibrium conditions has been studied. Calculations of changes in the entropy and internal energy of the adsorbent in the adsorption process were performed.

ADSORPTION OF BENZENE, ACETONE AND CARBON TETRACHLORIDE VAPORS ON MICROPOROUS CARBON ADSORBENT FAS-3

In this paper, the study of the adsorption of organic matter vapors (benzene, carbon tetrachloride, acetone) on the microporous carbon adsorbent FAS-3 in the region of pressures from 0.1 PA to 0.1 MPa and temperatures from 293 to 313 K was conducted, which showed sufficiently high adsorption characteristics of the used adsorbent in comparison with traditional absorbers. Microporous carbon adsorbent FAS-3 is quite new and still not fully understood. The purpose of this study was to determine the parameters of the adsorbent FAS-3, as well as the study of the processes of vapor adsorption of various organic substances on it. The microporous carbon adsorbent FAS-3, obtained on the basis of furfural, was used in the work. Obtaining spherical granules of the adsorbent FAS-3 was carried out in the result of liquid molding of a copolymer of furfural and epoxy resin on the basis of a fundamentally new process of combining the stages of blending monomer, molding the mixture in spherical product of the cured pellets. The activation of spherical grains of FAS-3 was carried out in a rotary kiln by a mixture of water vapor and carbon dioxide at a temperature of 850-900°C to burning that was consistent with the development of porosity in the adsorbent. The equilibrium values of vapor adsorption of substances on FAS-3 were measured on the gravimetric vacuum unit developed in the Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences. Regeneration of the adsorbent was carried out for 6 h at a temperature of 623 K to a pressure of 0.1 Pa. The maximum absolute measurement error was ± 0.01 mmol / g with 95% confidence. Measurement of vapor pressure of organic substances within 0.13 Pa-0.13 MPa was carried out by absolute pressure gauges M10, M1000, developed and manufactured in the Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences. The pressure measurement error by the manometer M10 in the range of 0.13 to 1330 Pa was ±0.066 Pa, and the manometer M1000 in the range from 13 Pa to 130 kPa was ±4.0 Pa.

ADSORPTION DEFORMATION OF MICROPOROUS CARBON ADSORBENT FAS AT ADSORP-TION OF WATER AND ACETONE VAPORS

For the first time, complex studies were carried out on adsorption deformation – sorbostriction of microporous carbon adsorbent FAS at adsorption of water and acetone vapors from the flow of carrier gas – nitrogen in non-equilibrium conditions. The results of this phenomenon were analyzed and the laws of the sorption of the microporous carbon adsorbent FAS during the adsorption of substances of different classes and different purposes in non-equilibrium conditions are established. In work a microporous carbon adsorbent FAS, obtained on the basis of furfural was used. Active coals on the basis of thermosetting plastics grades of FAS are significantly better than commercially-produced carbon adsorbents based on coal and peat on their mechanical properties and low ash content at a much greater development of the volume of the adsorbent micropores. We used the facility for studies of adsorption deformation of a solid adsorbent, manufactured in the Institute of Physical Chemistry and Electrochemistry of RAS. For the measurements we used a flow dilatometer, allowing measuring the adsorption deformation of the adsorbent while passing through it portions of the test substance or mixture in the carrier gas flow. It is shown that exit time of curves of sorbostriction to the maximum is individually for each of the studied substances, which enables you to use the effect of sorbostriction to detect the presence of certain substances in the mixture. The results of the wave sorbostriction of microporous carbon adsorbent FAS at adsorption of water and acetone vapors from the flow of carrier gas - nitrogen allow to conclude on the high selectivity of adsorption and the possibility of using the adsorbent as a sensor to control the content of these substances in a flow of nitrogen.