Temperature-programmed desorption study of Na2CO3-containing activated carbon

Wigmans, Teus; Doorn, J. van; Moulijn, Jacob A.

doi:10.1016/0016-2361(83)90196-5

Cited by 38 publications

(17 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Chemical analysis of the powder indicates that sodium is the most prevalent impurity. The sodium is likely in the form of either sodium carbonate or sodium oxide, both of which thermally decompose well below the heat‐treatment temperature of 1100°C …”

Section: Resultsmentioning

confidence: 99%

“…The sodium is likely in the form of either sodium carbonate or sodium oxide, both of which thermally decompose well below the heat-treatment temperature of 1100°C. 46,47 At the maximum temperature (T max = 1800°C), the maximum pressure (P max = 40 MPa) is slowly applied at a rate of 1.3 MPa/min. During this pressure-application step, the ethanol-washed powder (2 MPa, P1) experienced ~3.4 mm of shrinkage, while the heat-treated powder (2 MPa, P2) experienced ~3.8 mm of shrinkage.…”

Section: F I G U R E 3 Light Transmissionmentioning

confidence: 99%

See 1 more Smart Citation

Hot‐pressing platelet alumina to transparency

et al. 2019

View full text Add to dashboard Cite

Alumina powder with a platelet morphology was hot-pressed to transparency with preload pressures of 0-8 MPa, maximum temperatures of 1750-1825°C, maximum pressures of 2.5-80 MPa, and isothermal hold times of 1-7 hours. Optical transmission (in-line and total), as well as optical losses (backward/forward scattering and absorption), of the hot-pressed samples were measured and related to the microstructure. Higher hot-pressing temperatures increase the in-line transmission. A gray discoloration of the samples (indicative of high absorption) was minimized by heat treating the powder in air prior to hot pressing and reducing the preload pressure. Maximum pressures above/below 10 MPa increased porosity, which decreased inline transmission and increased backward/forward scattering. Lower densities at higher pressures are attributed to a pore-swelling phenomenon. Increasing isothermal hold time decreased porosity, which increased in-line transmission and reduced backward/forward scattering. Best optical properties with an in-line transmission of 65.3% at 645 nm (0.8 mm thick) were achieved by hot-pressing heat-treated platelet alumina powder with a preload pressure of 0 MPa, maximum temperature of 1800°C, maximum pressure of 10 MPa, and an isothermal hold time of 7 hours. This high inline transmission, despite its large grain size (65 µm), is attributed to crystallographic orientation of the platelets during hot pressing.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: F I G U R E 3 Light Transmissionmentioning

confidence: 99%

Hot‐pressing platelet alumina to transparency

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Figure S2 shows the differential thermogravimetric curves of all carbonaceous materials investigated in this study. Unwashed materials show a large peak located close to 540 K attributed to the desorption of water chemisorbed on carbonates [77] and to the partial desorption of carboxylic groups [70,78]. A good correlation between the oxygen contents obtained by integrating the OIII -O ads * peaks and from the mass loss related to the peak at 540-575 K was found and shown in Figure S3.a) and b).…”

Section: Composition and Surface Chemistrymentioning

confidence: 77%

Oxygen-promoted hydrogen adsorption on activated and hybrid carbon materials

Schaefer

Jeder

Sdanghi

et al. 2020

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

The effect of heteroatoms on hydrogen adsorption properties of activated and hybrid carbon materials is critically described. For that purpose, olive stones were activated chemically with KOH, and subsequently washed or not, and oxidised with ozone or not. Olive stones were also activated physically with CO 2 . A series of activated carbons prepared by chemical activation of sucrose was also investigated for comparison. As a result, many activated carbons with different pore-size distributions, surface areas, average micropore widths, oxygen contents and amounts of mineral matter could be compared. All were thoroughly characterised by adsorption of N 2 , CO 2 and H 2 O, elemental analysis, XPS, thermogravimetry, and adsorption of H 2 at different pressures. Many correlations between textural parameters, composition and adsorption properties could be evidenced, and were critically discussed. We show that the hydrogen uptake at 77 K is controlled by the following parameters, listed by decreasing order of importance: specific surface area, average micropore size, surface chemistry and shape of the pore size distribution. At room temperature (i.e., at 298 K), the adsorbed hydrogen uptake was in the range of 0.19 to 0.42 wt. %; the presence of large amounts of alkali metals can further improve the hydrogen adsorption properties, but surface chemistry still has a major influence, especially through the acidic surface functions.

show abstract

“…Several mechanisms [90] have been proposed for the catalysis, ranging from pure physical effects such as increasing C02 adsorption [97] and thermal mass transfer [98], to chemical effects such as electronic interaction [99,100] and electron transfer [101,102], reduction of carbon [86,87,102,103], and formation of oxides and surface complexes [104][105][106][107][108][109][110]. Temperature and molecular oxygen apparently play critical roles in the catalytic process [89,[111][112][113]. The role of oxygen in low-temperature ignition of cellulose char has been investigated [113].…”

Section: Smoldering Combustionmentioning

confidence: 99%

“…The catalytic effect of alkali metals on the oxidation and gasification of carbonaceous materials, including carbon, graphite, coal and cellulose char, is well known [85][86][87][88][89][90][91][92][93][94][95][96]. Several mechanisms [90] have been proposed for the catalysis, ranging from pure physical effects such as increasing C02 adsorption [97] and thermal mass transfer [98], to chemical effects such as electronic interaction [99,100] and electron transfer [101,102], reduction of carbon [86,87,102,103], and formation of oxides and surface complexes [104][105][106][107][108][109][110].…”

Section: Smoldering Combustionmentioning

confidence: 99%

Alkali Metal Ions and Their Effects on Smoldering and Ignition of Cotton Upholstery Fabrics-A Literature Review

Yeh

Song

Reznichenko

et al. 1993

Journal of Fire Sciences

View full text Add to dashboard Cite

Several studies have previously suggested that alkali metal ions such as potassium and sodium play a critical role in the smoldering and ignition of cotton upholstery fabrics. We have conducted an extensive review of the relevant literature to identify potential sources of these ions and to delineate possible mechanisms by which they affect the smoldering and ignition of cotton upholstery fabrics. The hazard associated with the cigarette ignition of cotton upholstery fabrics is addressed in terms of statistics on fire fatalities. Potential sources of alkali metal ions on the cotton fiber have been identified as being (1) from soil and agricultural chemicals used during the growth of the cotton plant and (2) from alkali agents used in textile wet processes such as dyeing and finishing.A general framework and pathway of cellulose degradation, smoldering combustion and ignition to flaming combustion is presented. Potential effects of alkali ions on each of these processes have been analyzed. The most probable role of these ions is suggested to be a catalytic effect on the oxidation of carbonaceous char (smoldering combustion).

show abstract

Temperature-programmed desorption study of Na2CO3-containing activated carbon

Cited by 38 publications

References 7 publications

Hot‐pressing platelet alumina to transparency

Hot‐pressing platelet alumina to transparency

Oxygen-promoted hydrogen adsorption on activated and hybrid carbon materials

Alkali Metal Ions and Their Effects on Smoldering and Ignition of Cotton Upholstery Fabrics-A Literature Review

Contact Info

Product

Resources

About