Carbon adsorption potential

For obtaining an average potential in the slit-like pore between the two layers of carbon, adsorption potential, an expression of adsorbate-adsorbent and adsorbate-adsorbate interactions resulted in the following equation. 

A pesticide formulation plant should prepare and implement an emergency preparedness and response plan that takes into account neighboring land uses and the potential consequences of an emergency or accidental release of harmful substances. Measures to avoid the release of harmful substances should be incorporated in the design, operation, maintenance, and management of the plant. Pollution control equipment employed in this sector include baghouses for removal of particulate matter and carbon adsorption for removal of VOCs. 

The concept of adsorption potential comes from work with high-purity, synthetic microporous carbon, which relies solely on van der Waals dispersive and electrostatic forces to provide the energy for adsorption. The polymeric microporous adsorbents that operate solely through van der Waals dispersive and electrostatic forces often cannot provide the surface potential energy needed to trap compounds that are gases under ambient conditions, and for very volatile compounds the trapping efficiency can be low for similar reasons. 

There are several potential treatment technologies that may be applicable, but are more expensive than the methods currently used. These potential treatments include sulfide precipitation, ultrafiltration, reverse osmosis, deep-well disposal, activated carbon adsorption or activated alumina adsorption, solidification, or ion exchange.19-21... 

R. K. Agarwal and J. A. Schwarz, Analysis of High-Pressure Adsorption of Gases on Activated Carbon by Potential-Theory, Carbon, 26, 873-887 (1988). 

Because most industrial effluent streams contain a multitude of contaminants in many different forms, the greatest potential for membrane separation technologies is in combination with such other technologies as ion exchange, activated carbon adsorption, anaerobic digestion, etc. 

One of the outstanding characteristics of the gas-solid interaction in single-walled carbon nanotubes is the significantly strengthened adsorption potential relative to the one on the... 

Now let us overview the theoretical adsorption models for characterization of the pore structures according to the pore size range. For physical adsorption of the gas molecules on such microporous solids as activated carbons and zeolites, Dubinin and Radushkevich95 developed an empirical equation, which describes the volume filling process in the micropores. Their theory incorporates earlier work by Polanyi96 in regard to the adsorption potential Ad defined as... 

A major development in understanding the adsorption of gases and vapors on microporous carbons was provided by the potential theory of adsorption by Polanyi. This theory assumes that, on the adsorbent surface, the gas molecules are compressed by attractive forces acting between the surface and the molecules, and these forces decrease with the increasing distance from the surface. The force of attraction at any given point near the surface is measured by the adsorption potential (A), which can be defined as the work done to transfer a molecule from the gas phase to a given point above the surface. 

Dubinin and coworkers, during the course of their extensive studies on activated carbons, have developed the so-called theory of volume filling of micropores. Based on numerous experimental data, Dubinin and collaborators have added a second postulate to the Polanyi theory, which complements it. For an identical degree of filling of the volume of adsorption space, the ratio of adsorption potentials for any two vapors is constant ... 

In the majority of applications of activated carbons as adsorbents of vapors and gases, the contaminants are removed owing to the enhanced adsorption potential in the small pores of activated carbons [5,134],... 

Abstract. The influence of an inert impregnant (NaCl) on the adsorption properties of activated carbon Norit R 0.8 Extra was studied on breakthrough dynamics of tert-butylbenzene (TBB) and dimethylmethylphosphonate (DMMP). Pre-adsorbed NaCl (5-20 wt.%) strongly affects both structural (e.g. volume of nanopores and mesopores) and adsorption (adsorption potential, breakthrough time, kinetic saturation capacity, etc.) characteristics. 

Figure 1. (a) Adsorption-desorption water isotherms at 293 K, and (b) adsorption potentials for water adsorbed onto carbon Norit at different CNaci values. 

When the adsorption potential, Eac, is low compared with the adsorbent selfpotential, Eco, as is usually the case for adsorption on active carbon. 

For one of our carbons we estimate that in some cases < a and C are of the order of 20% of the adsorption potential, assuming a Poisson ratio of 1/3. In these cases one may regard the adsorption potential as arising from a release of a compressive stress potential (80%) and a shear strain potential (20%). 

Immersion calorimetry provides a very useful means of assessing the total surface area of a microporous carbon (Denoyel et al., 1993). The basic principle of this method is that there is a direct relation between the energy of immersion and the total area of the microporous material. Indeed, for the two model cases of slit-shaped and cylindrical micropores, the predicted maximum enhancement of the adsorption potential (as compared with that of the flat surface of same nature) is 2.0 and 3.68, respectively (Everett and Powl, 1976). These values are remarkably similar to the increased surface area occupied by a molecule in the narrowest possible slit-shaped and cylindrical pores (i.e. 2.0 in a slit and 3.63 in a cylinder). To apply the method we... 

We have previously shown that a most interesting information provided by immersion microcalorimetry into organic liquids was, in the case of carbons, a direct assessment of the internal surface area of the micropores [1]. This conclusion was based on calculations of adsorption potentials in micropores, on geometrical considerations and on microcalorimetric measurements on a number of activated carbons. It was only validated for carbons. 

Single-component adsorption equilibria on activated carbon of the n-alkanes Q-C4 and of the odorant tert-butyl mercaptan were measured at the operating conditions expected in a large-scale facility for adsorbed natural gas (ANG) storage. The experimental data were correlated successfully with the Adsorption Potential theory and collapsed into a single temperature-independent characteristic curve. The obtained isotherm model should prove to be very useful for predicting the adsorption capacity of an ANG storage tank and to size and optimize the operation of a carbon-based filter for ANG applications. 

The main purpose of the present work is twofold (i) to report an extensive set of singlecomponent adsorption isotherm data of the more common natural gas components on activated carbon, and (ii) to present a means of extrapolating the measured data to higher alkanes in order to be able to span the whole composition of a typical natural gas. There is experimental evidence that for the n-alkanes series this can be done using the Adsorption Potential theory, as demonstrated recently by Holland et al. on Westvaco BAX-1100 carbon, and assumed previously by us. - ... 

The gravimetric measurements, as well as all other conventional adsorption methods, rather than giving the total amount adsorbed, q, give just the amount in excess, q, with respect to that of bulk gas occupjdng the same volume as the adsorbed phase. However, to apply the adsorption potential theory the required variable is q and not ex- In this work, q was estimated from the measured q i value by assuming that the adsorbed-phase volume is equal to the total pore volume of the carbon, = 0.850 cm /g, determined from N2... 

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