Optimizing Ammonia Adsorption Using Activated Carbon from Tamarind Pulp

Mass recovery can play an important role to better the performance of adsorption refrigeration cycles. Cooling capacity can be significantly increased with mass recovery process. The coefficient of performance (COP) of the activated carbon/ammonia adsorption refrigeration cycle might be increased or decreased with mass recovery process due to different working conditions. The advantage is that its COP is not sensitive to the variation of heat capacity of adsorber metal and condensing and evaporating temperature. The cycle with mass and heat recovery has a relatively high COP.

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Treatment of Gaseous Ammonia Emissions Using Date Palm Pits Based Granular Activated Carbon

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17051519 ◽

2020 ◽

Vol 17 (5) ◽

pp. 1519 ◽

Cited By ~ 2

Author(s):

Muhammad Vohra

Keyword(s):

Activated Carbon ◽

Functional Groups ◽

Gas Flow ◽

Date Palm ◽

Agricultural Waste ◽

Granular Activated Carbon ◽

Gaseous Ammonia ◽

Ammonia Adsorption ◽

Run Time ◽

Respective Surface

The present work investigated the application of granular activated carbon (GAC) derived from date palm pits (DPP) agricultural waste for treating gaseous ammonia. Respective findings indicate increased breakthrough time (run time at which 5% of influent ammonia is exiting with the effluent gas) with a decrease in influent ammonia and increase in GAC bed depth. At a gas flow rate of 1.1 L/min and GAC column length of 8 cm, the following breakthrough trend was noted: 1295 min (2.5 ppmv) > 712 min (5 ppmv) > 532 min (7.5 ppmv). A qualitatively similar trend was also noted for the exhaustion time results (run time at which 95% of influent ammonia is exiting with the effluent gas). The Fourier Transform Infrared Spectroscopy (FTIR) findings for the produced GAC indicated some salient functional groups at the produced GAC surface including O–H, C–H, C–O, and S=O groups. Ammonia adsorption was suggested to result from its interaction with the respective surface functional groups via different mechanisms. Comparison with a commercial GAC showed the date palm pits based GAC to be having slightly higher breakthrough and exhaustion capacity.

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The Functionalization of Activated Carbon by Oxidation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.846.251 ◽

2020 ◽

Vol 846 ◽

pp. 251-256

Author(s):

Supitcha Rungrodnimitchai ◽

Suphatra Hiranphinyophat

Keyword(s):

Activated Carbon ◽

Carbonyl Groups ◽

Ammonia Adsorption ◽

Sem Images ◽

Carboxyl Content ◽

Modified Activated Carbon ◽

Maximum Capacity ◽

Bet Analysis ◽

Scanning Electron ◽

Content Of Oxygen

Activated carbon is one of the most widely used adsorbents, but it shows low removal efficiency for polar molecules such as ammonia or ions due to the low content of oxygen containing groups. To increase the amount of oxygen containg groups, activated carbon was modified by the oxidation of activated carbon using the HNO3/H3PO4-NaNO2. The results showed that the carboxyl content of the modified activated carbon (MAC) increased with an increase in reaction time and temperature. The condition at 50°C for 60 hours yielded the MAC with a carboxyl content 1.07 mmol/g. The oxygen content of MAC also increased, suggesting the formation of carboxyl or carbonyl groups in the products after the oxidation. Brunauer-Emmett-Teller (BET) analysis and scanning electron microscopy (SEM) images demonstrated an increase in porosity of the MAC. The maximum capacity of ammonia adsorption was 5.81 mg/g for MAC.

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