scholarly journals A Study of the Removal of Minor Amounts of H2S from Natural Gas by Activated Carbon

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.

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.


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 53 (11) ◽  
pp. 4522-4523 ◽  
Author(s):  
Pradeepta K. Sahoo ◽  
Mathew John ◽  
Bharat L. Newalkar ◽  
N. V. Choudhary ◽  
K. G. Ayappa

Methane ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 24-37
Author(s):  
Muhammad Alfiza Farhan ◽  
Yuichi Sugai ◽  
Nuhindro Priagung Widodo ◽  
Syafrizal Syafrizal

The leakage of methane from the subsurface on the coalfield or natural gas field invariably becomes an important issue nowadays. In notable addition, materials such as activated carbon, zeolites, and Porapak have been successfully identified as adsorbents. Those adsorbents could adsorb methane at atmospheric pressure and room temperature. Therefore, in this scholarly study, a new method using adsorbents to detect points of methane leakage that can cover a wide-scale area was developed. In the beginning, the most capable adsorbent should be determined by quantifying adsorbed methane amount. Furthermore, checking the possibility of adsorption in the column diffusion and desorption method of adsorbents is equally necessary. The most capable adsorbent was activated carbon (AC), which can adsorb 1.187 × 10−3 mg-CH4/g-AC. Hereinafter, activated carbon successfully can adsorb methane through column diffusion, which simulates the situation of on-site measurement. The specific amount of adsorbed methane when the initial concentrations of CH4 in a bag were 200 ppm, 100 ppm, and 50 ppm was found to be 0.818 × 10−3 mg-CH4/g-AC, 0.397 × 10−3 mg-CH4/g-AC, 0.161 × 10−3 mg-CH4/g-AC, respectively. Desorption of activated carbon analysis shows that methane concentration increases during an hour in the temperature bath under 80 °C. In conclusion, soil methane leakage points can be detected using activated carbon by identifying the observed methane concentration increase.


2014 ◽  
Vol 526 ◽  
pp. 40-45 ◽  
Author(s):  
Xiao Pin Wang ◽  
Yi Hui Li ◽  
Cou Hua Zhu

This paper studied the changes in the surface morphology and microcrystalline structure of GAC modified using the original activated carbon, HNO3, FeCl2·4H20, KMnO4. The micro pore structure on the surface is damaged after being treated by HNO3, and the transition pores increase; after being treated by FeCl2·4H20 and KMnO4,the carbon surface is irregular, and there is a protuberance, which is due to the irregular loading of manganese ions on the activated carbon surface. Then the roughness of the activated carbon increases and the size of graphite crystallite of GAC is also greatly reduced, showing obvious trend of fine grains. Meanwhile, the studies of the effect of removing the trichlorophenol from water after modification indicate that the results basically match. On this basis, the modified model is put forward.


2019 ◽  
Vol 6 (3) ◽  
pp. 459-477 ◽  
Author(s):  
Jibril Abdulsalam ◽  
Jean Mulopo ◽  
Bilainu Oboirien ◽  
Samson Bada ◽  
Rosemary Falcon

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