Activated Carbon was produced from strong cation-exchange resins, sulphonated styrene divinylbenzene copolymers originally in H+ form, by means of carbonization and steam activation in an electrical furnace. One macroporous resin produced by BAYER Chemicals Inc., Lewatit MonoPlus SP 112 H, was used in the research. Products of carbonization and activation were characterized by using BET, Mercury Porosimetry, Helium Pycnometry and SEM techniques. The effect of carbonization time and temperature on the BET surface areas of the resins were also investigated.
Two sets of carbonization experiments (Set 1 and 2) were performed in which time and temperature were varied in order to study their effects on the BET surface areas of the products. In activation experiments (Set 3), carbonized ion-exchangers (600 oC, 1 hr) were activated with steam at 900° / C, changing the time of activation and the steam flow rate. The temperatures of the water bath used for steam generation were selected as 60° / C, 80° / C and 90° / C. The pore structures of activated carbons were determined by proper techniques. The volume and area of macropores in the pore diameter range of 8180-50 nm were determined by mercury intrusion porosimetry. Mesopore (in the range of 50-2 nm) areas and volumes were determined by N2 gas adsorption technique at -195.6oC, BET surface areas of the samples were also determined, in the relative pressure range of 0.05 to 0.02, by the same technique. The pore volume and the area of the micropores with diameters less than 2 nm were determined by CO2 adsorption measurements at 0oC by the application of Dubinin Radushkevich equation.
In the experiments of Sets 1 and 2, the BET surface area results of the six different carbonization times ranging from 0.5 to 3 hours gave almost the same value with a maximum deviation of 5% from the average showing almost no effect on the areas of the products. In the experiments of Set 3 , the sample activated at 800° / C for 6 hrs had the highest BET area, 2130 m2/g, and the one activated at 800° / C for 1 hr had the lowest BET area 636 m2/g. N2 adsorption/ desorption isotherms showed no distinct hysteresis indicating a cylindrical geometry of the pores. Adsorption isotherms further indicated that the pores are both highly microporous and mesoporous. N2 (BET) and CO2 (D-R) surface areas of the samples were in the range of 636-2130m2/g and 853-1858 m2/g, respectively. Surface areas of the samples consisted of about 8-53% mesopores and 47-92% micropores.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12605498/index.pdf |
| Date | 01 September 2004 |
| Creators | Abdallah, Wisam |
| Contributors | Yucel, Hayrettin |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
Page generated in 0.0021 seconds