Study on Thermal Regeneration for Caffeine-Saturated Activated Carbon

2013 ◽  
Vol 781-784 ◽  
pp. 1941-1944 ◽  
Author(s):  
Zhao You Zhu ◽  
Li Li Wang ◽  
Wan Ling Wang ◽  
Ying Long Wang

Waste activated carbon (AC) containing caffeine was produced during the process of the production for caffeine. The process of treatment caffeine-saturated AC using thermal regeneration was explored and factors on the regeneration of activated carbon were investigated. The optimum conditions obtained were: temperature is 650 °C, the regeneration time is 180 min, the carrier gas velocity is 0.002 m/s, carbon layer thickness is 0.1 m. Under these conditions, activated carbon regeneration efficiency reached 90.3%. In addition, the pore structure of activated carbon before and after regeneration was characterized and the activated carbon surface area and pore size distribution under optimum conditions were determined by the adsorption isotherms.

2014 ◽  
Vol 641-642 ◽  
pp. 1127-1130 ◽  
Author(s):  
Guo Ping Wang

As an effective adsorbent, activated carbon is widely used in the treatment of wastewater. Describes some of the regeneration of activated carbon for reference: thermal regeneration method, chemical regeneration, biological regeneration method, electrochemical regeneration, regeneration ozone oxidation, wet oxidation regeneration shown, supercritical carbon dioxide extraction regeneration, regeneration of catalytic oxidation method, microwave and ultrasonic regeneration and so on.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lilla Fijołek ◽  
Joanna Świetlik ◽  
Marcin Frankowski

AbstractIn water treatment technology, activated carbons are used primarily as sorbents to remove organic impurities, mainly natural organic matter, but also as catalysts in the ozonation process. Commercially available activated carbons are usually contaminated with mineral substances, classified into two main groups: alkali metals (Ca, Na, K, Li, Mg) and multivalent metals (Al, Fe, Ti, Si). The presence of impurities on the carbon surface significantly affects the pHpzc values determined for raw and ozonated carbon as well as their acidity and alkalinity. The scale of the observed changes strongly depends on the pH of the ozonated system, which is related to the diffusion of impurities from the carbon to the solution. In an acidic environment (pH 2.5 in this work), the ozone molecule is relatively stable, yet active carbon causes its decomposition. This is the first report that indirectly indicates that contaminants on the surface of activated carbon (multivalent elements) contribute to the breakdown of ozone towards radicals, while the process of ozone decomposition by purified carbons does not follow the radical path in bulk solution. Carbon impurities also change the distribution of the reaction products formed by organic pollutants ozonation, which additionally confirms the radical process. The study showed that the use of unpurified activated carbon in the ozonation of succinic acid (SA) leads to the formation of a relatively large amount of oxalic acid (OA), which is a product of radical SA degradation. On the other hand, in solutions with purified carbon, the amount of OA generated is negligible.


1997 ◽  
Vol 35 (7) ◽  
pp. 261-268 ◽  
Author(s):  
Kazuyuki Chihara ◽  
Kanji Oomori ◽  
Takao Oono ◽  
Yosuke Mochizuki

Supercritical CO2 regeneration is one of the possibilities for spent carbon regeneration loaded with some organics. Here, adsorption equilibrium and adsorption dynamics were evaluated for some typical organic pollutants under some supercritical CO2 conditions. A supercritical CO2 chromatograph packed with activated carbon (F-400, CAL) was used to detect the pulse responses of organics, which were analyzed by moment analysis. Adsorption equilibrium constants of some organics varied with CO2 density and their boiling points. Possibility of regeneration of each substance was discussed. Cost estimation was necessary and was the key point of this technique.


AIChE Journal ◽  
1988 ◽  
Vol 34 (10) ◽  
pp. 1656-1662 ◽  
Author(s):  
Peter Harriott ◽  
Alan Tat-Yan Cheng

2012 ◽  
Vol 184-185 ◽  
pp. 1110-1113 ◽  
Author(s):  
Li Fen He ◽  
Qi Xia Liu ◽  
Tao Ji ◽  
Qiang Gao

Various jute-based activated carbon fibers were prepared by using jute fibers as raw materials and phosphoric acid as activating agent. The effects of three main factors such as concentration of activating agent, activation temperature and activation time on the yield and adsorptive properties of active carbon fibers were investigated via orthogonal experiments. The surface physical morphology of jute-based activated carbon fiber was also observed by using Scanning Electron Microscope. Results showed that the optimum conditions were phosphoric acid concentration of 4 mol/L, activation temperature of 600 °C and activation time of 1h. The yield, iodine number and amount of methylene blue adsorption of the active carbon fiber prepared under optimum conditions were 37.99 %, 1208.87 mg/g and 374.65 mg/g, respectively.


2002 ◽  
Vol 20 (10) ◽  
pp. 969-976 ◽  
Author(s):  
Li Zhou ◽  
Ping Chen ◽  
Ming Li ◽  
Yaping Zhou

Studies have been made of the removal of minor amounts of H2S from natural gas by activated carbon. The surface alkalinity of the carbon had a considerable effect on the H2S capacity, although this was not permanent. Thus, when the carbon surface became neutral, the H2S content remained constant after the initial cycles of the purification/regeneration operation. The presence of water in natural gas was found to be critical for the use of activated carbon as a means of sweetening natural gas. However, although it enhanced the H2S capacity of the carbon, it made regeneration of the latter very difficult.


2020 ◽  
Vol 32 (5) ◽  
pp. 1121-1127
Author(s):  
Mahesh Kumar Gupta ◽  
P.K. Tandon ◽  
Neelam Shukla ◽  
Harendra Singh ◽  
Shalini Srivastava

Acid activated carbon obtained from cheap, non-toxic and locally available banana peel was used as a low cost and efficient adsorbent for the removal of dyes methyl orange and rhodamine-B from the aqueous solution. Changes in the resulting material before and after activation and after treatment were studied by different techniques, such as SEM-EDX, XRD, FTIR measurements. Effects of duration of treatment, amount of banana peel activated carbon, pH, and initial methyl orange and rhodamine-B concentration, on the removal of dye were studied to get optimum conditions for maximum dye removal. Removal efficiency of the activated ash remains almost constant in a wide range of pH from 2.5 to 5.6. In 75 min at room temperature removal of 98.5 % methyl orange (anionic) and 99.0 % rhodamine-B (cationic) dyes with 0.1 g and 0.125 g, respectively was obtained from the contaminated water having 10 ppm dye concentration.


1997 ◽  
Vol 35 (7) ◽  
pp. 279-285 ◽  
Author(s):  
P. C. Chiang ◽  
E. E. Chang ◽  
J. S. Wu

In this investigation, nine typical compounds, i.e., phenol, 2-aminophenol, aniline, 2-chlorophenol, chlorobenzene, β-naphthol, naphthalene, α-naphthylamine and α-chloronaphthalene were introduced to evaluate the effects of the molecular structure and physicochemical properties of these selected adsorbates on the adsorption capacity and desorption efficiency of the activated carbon. Both the thermal and chemical regeneration methods were employed to compare the regeneration efficiencies among these adsorbates and adsorbent.


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