Biochar From Cocoa Shell Pyrolysis: Potential Sorbent for CO2 Capture

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Hamed Abedini Najafabadi ◽  
Nesrin Ozalp ◽  
Richard A. Davis
Keyword(s):  
Activated Carbon ◽  
Co2 Capture ◽  
Co2 Adsorption ◽  
Lignin Content ◽  
Co2 Uptake ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Cocoa Shell ◽  
The Stability ◽  
Adsorption Desorption

Abstract Biochar produced from slow pyrolysis of cocoa shells was studied as a sorbent for CO2 capture. Three cocoa shell samples obtained from Papua New Guinea, Peru, and Colombia were studied. Thermogravimetric analysis showed that the first three stages of degradation were quite similar for different cocoa shell sources. However, the fourth stage was different, which could be due to the different lignin content in the cocoa shell sources. Chemical analysis showed that the cocoa shell biochar had a lower content of carbon and oxygen, and a higher content of magnesium, potassium, and calcium compared with the cocoa shell. CO2 uptake performance of the cocoa shell biochar was examined and compared with a commercial activated carbon using a thermogravimeter at atmospheric pressure and ambient temperature. The final CO2 uptake after 30 min was slightly higher for cocoa shell biochar. However, activated carbon had a faster adsorption response, and it approached equilibrium faster than the cocoa shell biochar. This could be due to differences in particle size, pore structure, and surface area of the activated carbon which allows the CO2 to be adsorbed easily in its porous structure. A pseudo-second-order model of kinetics fits the CO2 adsorption behavior of cocoa shell biochar and activated carbon indicating that the rate-limiting step is chemical adsorption. Furthermore, the stability of the cocoa shell sorbent was confirmed over four adsorption/desorption cycles. By considering the simplicity of the production process and efficiency of CO2 adsorption, cocoa shell biochar can be considered a good option for CO2 capture.

scholarly journals Electrospun Composites Made of Reduced Graphene Oxide and Polyacrylonitrile-Based Activated Carbon Nanofibers (rGO/ACNF) for Enhanced CO2 Adsorption

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2117
Author(s):  
Faten Ermala Che Othman ◽  
Norhaniza Yusof ◽  
Javier González-Benito ◽  
Xiaolei Fan ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Reduced Graphene Oxide ◽  
Carbon Nanofibers ◽  
Co2 Adsorption ◽  
Morphological Properties ◽  
Co2 Uptake ◽  
Order Model ◽  
Activated Carbon Nanofibers ◽  
Reduced Graphene

In this work, we report the preparation of polyacrylonitrile (PAN)-based activated carbon nanofibers composited with different concentrations of reduced graphene oxide (rGO/ACNF) (1%, 5%, and 10% relative to PAN weight) by a simple electrospinning method. The electrospun nanofibers (NFs) were carbonized and physically activated to obtain activated carbon nanofibers (ACNFs). Texture, surface and elemental properties of the pristine ACNFs and composites were characterized using various techniques. In comparison to pristine ACNF, the incorporation of rGO led to changes in surface and textural characteristics such as specific surface area (SBET), total pore volume (Vtotal), and micropore volume (Vmicro) of 373 m2/g, 0.22 cm3/g, and 0.15 cm3/g, respectively, which is much higher than the pristine ACNFs (e.g., SBET = 139 m2/g). The structural and morphological properties of the pristine ACNFs and their composites were studied by Raman spectroscopy and X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) respectively. Carbon dioxide (CO2) adsorption on the pristine ACNFs and rGO/ACNF composites was evaluated at different pressures (5, 10, and 15 bars) based on static volumetric adsorption. At 15 bar, the composite with 10% of rGO (rGO/ACNF0.1) that had the highest SBET, Vtotal, and Vmicro, as confirmed with BET model, exhibited the highest CO2 uptake of 58 mmol/g. These results point out that both surface and texture have a strong influence on the performance of CO2 adsorption. Interestingly, at p < 10 bar, the adsorption process of CO2 was found to be quite well fitted by pseudo-second order model (i.e., the chemisorption), whilst at 15 bar, physisorption prevailed, which was explained by the pseudo-first order model.

MICROWAVE ASSISTED K2CO3 PALM SHELL ACTIVATED CARBON AS SORBENT FOR CO2 ADSORPTION APPLICATION

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Usman Dadum Hamza ◽  
Noor Shawal Nasri ◽  
Nor Aishah Saidina Amin ◽  
Jibril Mohammed ◽  
Husna Mohd Zain
Keyword(s):  
Activated Carbon ◽  
Porous Carbon ◽  
Co2 Adsorption ◽  
Co2 Uptake ◽  
Adsorption Method ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Co2 Adsorption Capacity ◽  
Adsorption Equilibrium Data ◽  
Best Fit

Carbon dioxide is believed to be a major greenhouse gas (GHG) that contributes to global warming. In this study, palm shells were used as a precursor to prepare CO2 activated carbon sorbents via carbonization, chemical impregnation with K2CO3 and microwave activation.  Adsorption equilibrium data for CO2 adsorption on the porous carbon were obtained at different temperatures using static volumetric adsorption method. Langmuir, Freundlich, Sips and Toths models were used to correlate the experimental data. The CO2 adsorption capacity at 303.15, 343.15, 378.15 443.15 K and 1 bar on the sorbent was 2.71, 1.5, 0.77, 0.69 mmol/g respectively. Sips isotherm was found to have the best fit. The results indicated that the porous carbon sorbent prepared by carbonization and microwave K2CO3 assisted activation have good CO2 uptake. The porous carbons produced are therefore good candidates for CO2 adsorption applications

scholarly journals Carbon Dioxide Adsorption on Porous and Functionalized Activated Carbon Fibers

2019 ◽  
Vol 9 (10) ◽  
pp. 1977 ◽  
Author(s):  
Yu-Chun Chiang ◽  
Cheng-Yu Yeh ◽  
Chih-Hsien Weng
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Surface Area ◽  
Carbon Fibers ◽  
Pore Volume ◽  
Co2 Adsorption ◽  
Physical Adsorption ◽  
Koh Activation ◽  
Co2 Uptake ◽  
Activated Carbon Fibers

Polyacrylonitrile-based activated carbon fibers (ACFs), modified using potassium hydroxide (KOH) or tetraethylenepentamine (TEPA), were investigated for carbon dioxide (CO2) adsorption, which is one of the promising alleviation approaches for global warming. The CO2 adsorption isotherms were measured, and the values of isosteric heat of adsorption were calculated. The results showed that the KOH-modified ACFs exhibited a great deal of pore volume, and a specific surface area of 1565 m2/g was obtained. KOH activation made nitrogen atoms easily able to escape from the surface of ACFs. On the other hand, the surface area and pore volume of ACFs modified with TEPA were significantly reduced, which can be attributed to the closing or blocking of micropores by the N-groups. The CO2 adsorption on the ACF samples was via exothermic reactions and was a type of physical adsorption, where the CO2 adsorption occurred on heterogeneous surfaces. The CO2 uptakes at 1 atm and 25 °C on KOH-activated ACFs reached 2.74 mmole/g. This study observed that microporosity and surface oxygen functionalities were highly associated with the CO2 uptake, implying the existence of O-C coordination, accompanied with physical adsorption. Well cyclability of the adsorbents for CO2 adsorption was observed, with a performance decay of less than 5% over up to ten adsorption-desorption cycles.

scholarly journals Biocarbon Derived from Opuntia ficus indica for p-Nitrophenol Retention

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1242
Author(s):  
Hanedi Elhleli ◽  
Faten Mannai ◽  
Mongi ben Mosbah ◽  
Ramzi Khiari ◽  
Younes Moussaoui
Keyword(s):  
Activated Carbon ◽  
Fourier Transforms ◽  
Activated Carbons ◽  
Removal Rate ◽  
Order Model ◽  
Opuntia Ficus Indica ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Fourier Transforms Infrared Spectroscopy ◽  
Adsorption Desorption

Activated carbon obtained from Opuntia ficus indica by sodium hydroxide activation was employed for the adsorption of p-nitrophenol from water. The activated carbons obtained were characterized by Fourier transforms infrared spectroscopy, sorption of nitrogen, scanning electron microscopy, and Boehm titration. Effects of pH, contact time, amount of adsorbent, and temperature on the adsorption of p-nitrophenol were studied. Adsorption isotherms were analyzed using Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich models, and the thermodynamic parameters have been determined. The adsorption of p-nitrophenol was spontaneous, exothermic, and propitious at 15 °C and adopted the pseudo-second order model, and the most credible isotherm was Langmuir’s one. The activated carbon used in this work has good p-nitrophenol adsorption characteristics, and the study of the desorption and reuse of this carbon shows that it retains a removal rate greater than 94% after five cycles of adsorption-desorption.

scholarly journals Roles of London Dispersive and Polar Components of Nano-Metal-Coated Activated Carbons for Improving Carbon Dioxide Uptake

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Seul-Yi Lee ◽  
Jong-Hoon Lee ◽  
Yeong-Hun Kim ◽  
Kyong-Yop Rhee ◽  
Soo-Jin Park
Keyword(s):  
Co2 Capture ◽  
Co2 Adsorption ◽  
Activated Carbons ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Economic Benefits ◽  
Co2 Uptake ◽  
Carbon Dioxide Uptake ◽  
Polar Components ◽  
Adsorption Behaviors

Adsorption using carbonaceous materials has been considered as the prevailing technology for CO2 capture because it offers advantages such as high adsorption capacity, durability, and economic benefits. Activated carbon (AC) has been widely used as an adsorbent for CO2 capture. We investigated CO2 adsorption behaviors of magnesium oxide-coated AC (MgO-AC) as a function of MgO content. The microstructure and textural properties of MgO-AC were characterized by X-ray diffraction and nitrogen adsorption–desorption isotherms at 77 K, respectively. The CO2 adsorption behaviors of MgO-AC were evaluated at 298 K and 1 atm. Our experimental results revealed that the presence of MgO plays a key role in increasing the CO2 uptake through the interaction between an acidic adsorbate (e+) and an efficient basic adsorbent (e−).

scholarly journals Brasil nut mesocarp (Bertholletia excels) as a Biomass Source for Activated Carbon Production: Correlation Between Thermal Treatment and Adsorption Performance

2021 ◽  
Vol 12 (4) ◽  
pp. 4584-4596
Keyword(s):  
Activated Carbon ◽  
Maximum Adsorption Capacity ◽  
Brazil Nut ◽  
Order Model ◽  
X Ray ◽  
Adsorption Performance ◽  
Carbon Production ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Best Fit

The activated carbon investigated in this work was produced from the extractive residues of Brazil nut processing, more specifically from the mesocarp of the Amazonian fruit. The process was performed by muffle pyrolysis, with ZnCl2 impregnation, at 400 and 500 °C. All samples were characterized by X-ray diffractometry, thermogravimetry, CHNS elemental analysis, scanning electron microscopy, and adsorption/desorption of N2. The results were promissory, with 99% removal of methylene blue for the CA25 material, which has a surface area of 1236 m2 g-1, much higher than commercial coal (CAC, 618 m2 g-1). The adsorption kinetics best fit the pseudo-second-order model for all materials. The maximum adsorption capacity obtained was 195.3 mg g-1. Therefore, the extractive residue of Brazil nut has excellent potential for the development of activated carbon, which can be used effectively to mediate environmental contamination in a given aqueous medium.

scholarly journals Studies of adsorption kinetics and regeneration of aniline, phenol, 4-chlorophenol and 4-nitrophenol by activated carbon

2013 ◽  
Vol 19 (2) ◽  
pp. 195-212 ◽  
Author(s):  
S. Suresh ◽  
V.C. Srivastava ◽  
I.M. Mishra
Keyword(s):  
Activated Carbon ◽  
Thermal Desorption ◽  
Kinetic Studies ◽  
Order Model ◽  
Heating Value ◽  
High Heating Value ◽  
Ftir Spectral Analysis ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Desorption Cycle

The present paper reports kinetic studies of the adsorption of aniline (AN), phenol (P), 4-chlorophenol (CP) and 4-nitrophenol (NP) from aqueous solution onto granular activated carbon (GAC). In FTIR spectral analysis, the transmittance of the peaks gets increased after the loading of AN, P, CP and NP signifying the participation of these functional groups in the adsorption and it seems that the adsorption of AN, P, CP and NP is chemisorptive in nature. The rates of adsorption were found to obey a pseudo-second order model and that the dynamics of AN, P, CP and NP adsorption are controlled by a combination of surface and pore diffusion. The diffusion coefficient were of the order of 10-10 m2 s-1. Thermal desorption at 623 K was found to be more effective than solvent desorption. GAC performed well for at least five adsorption-desorption cycle, with continuous decrease in adsorption efficiency after each thermal desorption. Owing to its relative high heating value, the spent GAC can be used as co-fuel for the production of heat in a boiler or a furnace.

scholarly journals Adsorption Performance of Physically Activated Biochars for Postcombustion CO2 Capture from Dry and Humid Flue Gas

2020 ◽  
Vol 10 (1) ◽  
pp. 376 ◽  
Author(s):  
Joan J. Manyà ◽  
David García-Morcate ◽  
Belén González
Keyword(s):  
Wheat Straw ◽  
Co2 Capture ◽  
Co2 Adsorption ◽  
Packed Bed ◽  
Dry Conditions ◽  
Stable Performance ◽  
High Concentrations ◽  
Hierarchical Pore ◽  
Cyclic Adsorption ◽  
Adsorption Desorption

In the present study, the performance of four biomass-derived physically activated biochars for dynamic CO2 capture was assessed. Biochars were first produced from vine shoots and wheat straw pellets through slow pyrolysis (at pressures of 0.1 and 0.5 MPa) and then activated with CO2 (at 0.1 MPa and 800 °C) up to different degrees of burn-off. Cyclic adsorption-desorption measurements were conducted under both dry and humid conditions using a packed-bed of adsorbent at relatively short residence times of the gas phase (12–13 s). The adsorbent prepared from the vine shoots-derived biochar obtained by atmospheric pyrolysis, which showed the most hierarchical pore size distribution, exhibited a good and stable performance under dry conditions and at an adsorption temperature of 50 °C, due to the enhanced CO2 adsorption and desorption rates. However, the presence of relatively high concentrations of water vapor in the feeding gas clearly interfered with the CO2 adsorption mechanism, leading to significantly shorter breakthrough times. In this case, the highest percentages of a used bed were achieved by one of the other activated biochars tested, which was prepared from the wheat straw-derived biochar obtained by pressurized pyrolysis.

scholarly journals Highly Selective CO2 Capture on Waste Polyurethane Foam-Based Activated Carbon

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 592 ◽  
Author(s):  
Chao Ge ◽  
Dandan Lian ◽  
Shaopeng Cui ◽  
Jie Gao ◽  
Jianjun Lu
Keyword(s):  
Activated Carbon ◽  
Polyurethane Foam ◽  
Co2 Capture ◽  
Carbon Materials ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Physical Activation ◽  
Activation Process ◽  
Co2 Uptake ◽  
High Co2

Low-cost activated carbons were prepared from waste polyurethane foam by physical activation with CO2 for the first time and chemical activation with Ca(OH)2, NaOH, or KOH. The activation conditions were optimized to produce microporous carbons with high CO2 adsorption capacity and CO2/N2 selectivity. The sample prepared by physical activation showed CO2/N2 selectivity of up to 24, much higher than that of chemical activation. This is mainly due to the narrower microporosity and the rich N content produced during the physical activation process. However, physical activation samples showed inferior textural properties compared to chemical activation samples and led to a lower CO2 uptake of 3.37 mmol·g−1 at 273 K. Porous carbons obtained by chemical activation showed a high CO2 uptake of 5.85 mmol·g−1 at 273 K, comparable to the optimum activated carbon materials prepared from other wastes. This is mainly attributed to large volumes of ultra-micropores (<1 nm) up to 0.212 cm3·g−1 and a high surface area of 1360 m2·g−1. Furthermore, in consideration of the presence of fewer contaminants, lower weight losses of physical activation samples, and the excellent recyclability of both physical- and chemical-activated samples, the waste polyurethane foam-based carbon materials exhibited potential application prospects in CO2 capture.

Kinetics of CO2 Adsorption on Microwave Palm Shell Activated Carbon

2014 ◽  
Vol 1043 ◽  
pp. 224-228 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Usman Dadum Hamza ◽  
Nor Aishah Saidina Amin ◽  
Jibril Mohammed ◽  
Murtala Musa Ahmed ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Co2 Adsorption ◽  
Activated Carbons ◽  
Diffusion Mechanism ◽  
Co2 Uptake ◽  
Intraparticle Diffusion Model ◽  
Palm Shell ◽  
Model Pore ◽  
Pseudosecond Order ◽  
Kinetics Of

Activated carbon was prepared from palm shell by pyrolysis followed by K2CO3 assisted microwave heating. Effects of temperature on adsorption capability and kinetics of the sorbent towards CO2 adsorption was also studied. The results indicated that, the amount CO2 adsorbed decrease as the adsorption temperature increases. The kinetic data were obtained using a static volumetric method at 303.15, 343.15, 378.15, and 443.15 K and at pressures up to 4 bar. The kinetics of CO2 adsorption on the activated carbons was examined using the pseudofirst-order equation and pseudosecond-order equations. Weber and Morris intraparticle diffusion model was applied to examine the mechanism of the adsorption system. Lowest CO2 uptake recorded was 0.3 mmol/g at 443.15 K and 0.5 bar while the highest was 7.45mmol/g obtained at 303.15 K and 4 bar. The kinetics followed pseudosecond-order model. Pore diffusion is not the sole rate diffusion mechanism.

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