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

Author(s):  
Muhammad Vohra

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.

Author(s):  
Muhammad Vohra ◽  
Mohammad Al-Suwaiyan ◽  
Minaam Hussaini

Activated carbon that has been widely used for several environmental applications is typically produced from carbon-based raw materials including agricultural by-products. To that end, extensive date palm-tree farming across the globe with millions of palm trees, also results in various types of agricultural waste including date palm-tree branches (DPB) during the regular trimming phase of palm-trees. Furthermore, air pollution also remains a serious concern in many global regions, requiring the application of appropriate treatment technologies to mitigate the respective negative effects on human health and environment. The present study thus assessed the efficiency of activated carbon (AC) derived from date palm-tree branches to treat gaseous toluene (C6H5CH3) streams under varying dynamic flow conditions. The produced activated carbon showed BET specific surface area (SSABET) of 800.87 m2/g with micro and mesoporous structure. The AC FTIR results indicated several surface groups including oxygen based functional groups. Furthermore, the dynamic gas treatment results showed that the respective activated carbon can successfully treat gaseous toluene under varying gas flow rates, gas concentrations and activated carbon bed depths. An increase in the carbon bed depth and decrease in toluene gas concentration and/or flow rate, yielded higher breakthrough time (BT) and exhaustion time (ET) values. Adsorption modeling employing the response surface methodology (RSM) approach successfully modeled the respective gaseous toluene removal experimental findings, with breakthrough time (BT) and exhaustion time (ET) as the response factors. The respective model-fitting parameters showed good outcomes using natural logarithmic transform model.


2018 ◽  
Vol 67 ◽  
pp. 03019 ◽  
Author(s):  
Yuliusman ◽  
Nasruddin ◽  
Yugo WidhiNugroho ◽  
Hizba IlmiNaf’an ◽  
Jervis Sinto

Adsorbed natural gas (ANG) can be developed through its porous adsorbent, especially activated carbon (AC) which has larger specific surface area. AC made of soybean straw is developed because of its abundance as agricultural waste in Indonesia and high lignocellulosic content. AC is produced in 500°C furnace for 1 hour with nitrogen gas flow of 200 mL/minute. For AC production, variations of chemical activating agents utilizing ZnCl2 and KOH and the concentration NiO as modification substance are made in this paper. Characterizations are made through iodine number, SEM, EDX, and nitrogen adsorption-desorption for obtaining data of adsorption capacity, surface topography, main composition, and particles specification. ZnCl2 activated carbon shows better result with iodine number of 577.73 mg/g and SBET of 741.26 m2/g, and the second-best is found in 2%-NiO-modified ZnCl2 activated carbon with iodine number of 534.79 mg/g and SBET of 632.24 m2/g. It is concluded that development of soybean straw as activated carbon precursor is still needed to obtain larger SBETand better adsorption capacity.


2019 ◽  
Vol 11 (22) ◽  
pp. 6204 ◽  
Author(s):  
Kalu Ukanwa ◽  
Kumar Patchigolla ◽  
Ruben Sakrabani ◽  
Edward Anthony ◽  
Sachin Mandavgane

The choice of activating agent for the thermochemical production of high-grade activated carbon (AC) from agricultural residues and wastes, such as feedstock, requires innovative methods. Overcoming energy losses, and using the best techniques to minimise secondary contamination and improve adsorptivity, are critical. Here, we review the importance and influence of activating agents on agricultural waste: how they react and compare conventional and microwave processes. In particular, adsorbent pore characteristics, surface chemistry interactions and production modes were compared with traditional methods. It was concluded that there are no best activating agents; rather, each agent reacts uniquely with a precursor, and the optimum choice depends on the target adsorbent. Natural chemicals can also be as effective as inorganic activating agents, and offer the advantages that they are usually safe, and readily available. The use of a microwave, as an innovative pyrolysis approach, can enhance the activation process within a duration of 1–4 h and temperature of 500–1200 °C, after which the yield and efficiency decline rapidly due to molecular breakdown. This study also examines the biomass milling process requirements; the influence of the dielectric properties, along with the effect of washing; and experimental setup challenges. The microwave setup system, biomass feed rate, product delivery, inert gas flow rate, reactor design and recovery lines are all important factors in the microwave activation process, and contribute to the overall efficiency of AC preparation. However, a major issue is a lack of large-scale industrial demonstration units for microwave technology.


2011 ◽  
Vol 264-265 ◽  
pp. 535-541 ◽  
Author(s):  
Yusuf Bamidele Onundi ◽  
Abdullah Al-Mamun ◽  
Ma’an Fami R. Al-Khatib ◽  
Yehya M. Ahmed

Since the discovery of carbon nanotubes (CNT) and subsequent Carbon Nanomaterials (CNMs), there has been an ever increased academic and industrial interest on there various fields of application due to their exceptional mechanical and electrical properties. In this work, granular activated carbon (GAC) made from palm Kernel shell (PKS) of mesh size 8x12 was impregnated with nickel as substrate catalyst for the growth of Carbon Nanomaterials (CNMs) in a chemical decomposition (CVD) reactor. Various percentages by weight of the nickel (1%, 3%, 5% and 7%) were impregnated on the GAC surface for CNM growth. The CNM growth took place at a fixed reaction temperature and gas flow rates for both the hydrogen gas and carbon source. Characterization of the novel composite material was carried out by using SEM, FESEM and TEM. The results show that growth was successful as at 1% nickel impregnation, while a denser network distribution and rougher surface of CNM was observed at 7% nickel. The growth of CNMs on a larger substrate GAC should make handling of the CNMs easier and it is expected to also open new doors of application in water treatment and oil refining.


Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2460
Author(s):  
Feifei Wang ◽  
Lu Zhang ◽  
Liangfu Wei ◽  
Jan Peter van der Hoek

During drinking water treatment, advanced oxidation process (AOP) with O3 and H2O2 may result in by-products, residual H2O2 and BrO3−. The water containing H2O2 and BrO3− often flows into subsequent granular activated carbon (GAC) filters. A concentrated H2O2 solution can be used as GAC modification reagent at 60 °C to improve its adsorption ability. However, whether low concentrations of H2O2 residuals from AOP can modify GAC, and the impact of H2O2 residuals on BrO3− removal by the subsequent GAC filter at ambient temperature, is unknown. This study evaluated the modification of GAC surface functional groups by residual H2O2 and its effect on BrO3− removal by GAC. Results showed that both H2O2 and BrO3− were effectively removed by virgin GAC, while pre-loaded and regenerated GACs removed H2O2 but not BrO3− anymore. At the ambient temperature 150 µmol/L H2O2 residuals consumed large amounts of functional groups, which resulted in the decrease of BrO3− removal by virgin GAC in the presence of H2O2 residuals. Redox reactions between BrO3− and surface functional groups played a dominant role in BrO3− removal by GAC, and only a small amount of BrO3− was removed by GAC adsorption. The higher the pH, the less BrO3− removal and the more H2O2 removal was observed.


2011 ◽  
Vol 233-235 ◽  
pp. 765-773
Author(s):  
Zhao Yang Lu ◽  
Bi Cun Jiang ◽  
Ai Min Li ◽  
Jun Fan

For comparing the adsorption of Synthetic Organic Chemicals (SOC) competing with background pollutants between a bifunctional resin and a commercial granular activated carbon (GAC), tannic acid (TA) was preloaded to the two adsorbents at quantities of 60 and 120 μmol/g. As a result, decreases of micropores volume in the resin were 75.5 and 98.9%, while those in the GAC were only 19.0 and 30.0%, respectively. Preloading attenuated surface heterogeneities and phenol’s capacities of two adsorbents distinctly. But maximumly, 1.0 mole TA’s preloading on GAC could decline 9.23 mole phenol’s adsorption. Under the same condition, the resin’s capacity of phenol was only descended at 2.68 times, when 98.9% micropores have been blocked. In kinetic tests, blockages in the resin were misapprehended to be much lighter than those in the GAC by the Homogeneous Surface Diffusion Model (HSDM). One steady operation engineering at micropore volume 37.8% decline was introduced. The conflicts were explained by quite a number of resin’s functional groups in the macroporous and mesoporous region could attract enough phenol molecular rapidly, even if almost all micropores were blocked.


2020 ◽  
Author(s):  
Feng Xiao ◽  
Bin Yao ◽  
Pavankumar Challa Sasi ◽  
Svetlana Golovko ◽  
Dana Soli ◽  
...  

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