• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Production And Characterization Of Activated Carbon From Sulphonated Styrene Divinylbenzene Copolymer

Abdallah, Wisam 01 September 2004 (has links) (PDF)
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&deg / 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&deg / C, 80&deg / C and 90&deg / 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&deg / C for 6 hrs had the highest BET area, 2130 m2/g, and the one activated at 800&deg / 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.
2

Magnetic Activated Carbon Production from Lignin and Ferrous Salts : Process Modification for Enhanced Phosphate Adsorption from Aqueous Solutions

Zheng, Zhaoran January 2020 (has links)
The treatment and control of superfluous aqueous phosphate is a critical task in environmental management. Magnetic bio-activated carbon is a good adsorbent for physical adsorption methods with several environmental and economic advantages. A streamlined and new method for production of magnetic bio-activated carbon from lignin is finished and presented by Tong Han. To enhance the phosphate adsorption and find the optimization process for mac production from lignin, it’s necessary to investigate influence of process parameters on the quality of the final products systematically. In this work, four different modification of process are used to investigate the influence of process parameters on the quality of the final products systematically, which shows how the proportion of iron oxides, the dispersion of iron oxides and the degree of activation influence the capacities. And the maximum capacity is around 50mg/g, which is a relatively high improvement. / Behandling och kontroll av överflödigt vattenhaltigt fosfat är en kritisk uppgift i miljöhantering. Magnetiskt bioaktiverat kol är ett bra adsorbent för fysiska adsorptionsmetoder med flera miljömässiga och ekonomiska fördelar. En strömlinjeformad och ny metod för produktion av magnetiskt bioaktiverat kol från lignin är färdig och presenteras av Tong Han. För att förbättra fosfatadsorptionen och hitta optimeringsprocessen för mac-produktion från lignin är det nödvändigt att systematiskt undersöka påverkan av processparametrar på kvaliteten på de slutliga produkterna. I detta arbete används fyra olika modifieringar av processen för att systematiskt undersöka påverkan av processparametrar på slutprodukternas kvalitet, vilket visar hur andelen järnoxider, spridningen av järnoxider och graden av aktivering påverkar kapaciteten. Och den maximala kapaciteten är cirka 50 mg / g, vilket är en relativt hög förbättring.

Page generated in 0.0804 seconds