Influence of the origin of chars, produced from lignite by different methods, on features of their activation process

Activation of Pyrolytic Lignite Char with CO2. Kinetic Study

“…The PSD obtained from the mercury intrusion curve is shown in Figure . A heterogeneous PSD between 15 and 300 nm with a porosity of 0.19 is observed, close to the reported value in the literature for similar materials. , Different equations were applied to the N 2 and CO 2 isotherms of the sample in order to study the pores in the range of micro- and mesoporosity. In Table , a high value for BET surface area can be observed, probably as a result of the microporosity in the sample because the total micropore volume is around 75% of the total pore volume (see Table ).…”

“…The char volatile matter content is 7.5% (see Table ) despite using extreme conditions for carbonization. However, this trend has also been observed in several works − with different lignite coals and pyrolysis conditions.…”

“…In this figure, an important proportion of pores between 0.5 and 0.8 nm is observed. This relevant presence of micropores in the char has been explained because of the reaction of the carbon atoms in the pore walls during the pyrolysis step with the oxygen present in the original lignite 1 Pore size distribution of the lignite-derived char (mercury porosimetry).

2 Micropore size distribution of the lignite-derived char (N 2 DFT method).

2 Textural Properties of the Lignite-Derived Char S BET (m 2 /g) 278 total pore volume (cm 3 /g) 0.19 total micropore volume (cm 3 /g) 0.14 narrow micropore volume (cm 3 /g) 0.243 exponent n DA in Dubinin−Astakhov equation1.9 adsorption characteristic energy in Dubinin-Astakhov equation (J/mol)21 000 average micropore width (nm) 1.08 …”

Preparation of activated carbons from Zonguldak region coals by physical and chemical activations for hydrogen sorption

“…Shchipko and Kuznestsov [22] observed that the type of gas-solid contact in a fluidized bed reactor promoted the formation of mesopores during the activation process. Linares-Solano et al [23] observed that physical activation carried out in a fluidized bed reactor, either with steam or with carbon dioxide, considerably reduced the necessary reaction time compared to fixed bed conditions.…”

Preparation of steam-activated carbons as catalyst supports

“…to a better temperature control. Shchipko and Kuznestsov [7] observed that the type of gas-solid contact achieved in a fluidized bed reactor promoted the formation of mesopores during the activation process. In addition, Linares-Solano [8] observed that physical activation carried out in a fluidized bed reactor, either with steam or with carbon dioxide, considerably reduced the necessary reaction time compared to fixed bed conditions.…”