scholarly journals Upgrading of Biogas to Methane Based on Adsorption

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 941
Author(s):  
Jun Liu ◽  
Qiang Chen ◽  
Peng Qi

Upgrading raw biogas to methane (CH4) is a vital prerequisite for the utilization of biogas as a vehicle fuel or the similar field as well. In this work, biogas yield from the anaerobic fermentation of food waste containing methane (CH4, 60.4%), carbon dioxide (CO2, 29.1%), hydrogen sulfide (H2S, 1.5%), nitrogen (N2, 7.35%) and oxygen (O2, 1.6%) was upgraded by dynamic adsorption. The hydrogen sulfide was removed from the biogas in advance by iron oxide (Fe2O3) because of its corrosion of the equipment. Commercial 13X zeolite and carbon molecular sieve (CMS) were used to remove the other impurity gases from wet or dry biogas. It was found that neither 13X zeolite nor CMS could effectively remove each of the impurities in the wet biogas for the effect of water vapor. However, 13X zeolite could effectively remove CO2 after the biogas was dried with silica and showed a CO2 adsorption capacity of 78 mg/g at the condition of 0.2 MPa and 25 °C. Additionally, 13X zeolite almost did not adsorb nitrogen (N2), so the CH4 was merely boosted to ac. 91% after the desulfurated dry biogas passed through 13X zeolite, nitrogen remaining in the biogas. CMS would exhibit superior N2 adsorption capacity and low CO2 adsorption capacity if some N2 was present in biogas, so CMS was able to remove all the nitrogen and fractional carbon dioxide from the desulfurated dry biogas in a period of time. Finally, when the desulfurated dry biogas passed through CMS and 13X zeolite in turn, the N2 and CO2 were sequentially removed, and then followed the high purity CH4 (≥96%).

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 634 ◽  
Author(s):  
Shazia Shukrullah ◽  
Muhammad Yasin Naz ◽  
Norani M. Mohamed ◽  
Khalid A. Ibrahim ◽  
Nasser M. AbdEl-Salam ◽  
...  

Carbon dioxide is one of the major greenhouse gases and a leading source of global warming. Several adsorbent materials are being tested for removal of carbon dioxide (CO2) from the atmosphere. The use of multiwalled carbon nanotubes (MWCNTs) as a CO2 adsorbent material is a relatively new research avenue. In this study, Fe2O3/Al2O3 composite catalyst was used to synthesize MWCNTs by cracking ethylene gas molecules in a fluidized bed chemical vapor deposition (CVD) chamber. These nanotubes were treated with H2SO4/HNO3 solution and functionalized with 3-aminopropyl-triethoxysilane (APTS). Chemical modification of nanotubes removed the endcaps and introduced some functional groups along the sidewalls at defected sites. The functionalization of nanotubes with amine introduced carboxylic groups on the tube surface. These functional groups significantly enhance the surface wettability, hydrophilicity and CO2 adsorption capacity of MWCNTs. The CO2 adsorption capacity of as-grown and amine-functionalized CNTs was computed by generating their breakthrough curves. BELSORP-mini equipment was used to generate CO2 breakthrough curves. The oxidation and functionalization of MWCNTs revealed significant improvement in their adsorption capacity. The highest CO2 adsorption of 129 cm3/g was achieved with amine-functionalized MWCNTs among all the tested samples.


CrystEngComm ◽  
2015 ◽  
Vol 17 (2) ◽  
pp. 430-437 ◽  
Author(s):  
Carlos Palomino Cabello ◽  
Gloria Berlier ◽  
Giuliana Magnacca ◽  
Paolo Rumori ◽  
Gemma Turnes Palomino

Functionalization of the MIL-100(Cr) metal–organic framework with alkylamines (ethylenediamine and N,N′-dimethylethylenediamine) improves carbon dioxide sorption properties, especially in the case of ethylenediamine.


2019 ◽  
Vol 90 ◽  
pp. 01010 ◽  
Author(s):  
Noor Ashikin Mohamad ◽  
Ebrahim Abouzari Lotf ◽  
M. Nasef Mohamed ◽  
Ahmad Arshad ◽  
TAT Abdullah

The paper presents a study for investigating i) the effect of amination of poly(GMA)-grafted polyethylene/polypropylene (PE/PP) substrates with trimethylamine (TMA) and ethylenediamine (EDA) and ii) their impact on carbon dioxide (CO2) adsorption capacity of the obtained adsorbents. The chemical, structural, and morphological changes of the aminated adsorbents were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. The amination yield with TMA was 40% higher than EDA. However, the obtained adsorbent showed two times lower CO2 adsorption capacity (at 30 bars) than the adsorbent with EDA and stood at 0.6 mmol g-1 compared to 1.2 mmol g-1.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1776
Author(s):  
Phuwadej Pornaroontham ◽  
Gasidit Panomsuwan ◽  
Sangwoo Chae ◽  
Nagahiro Saito ◽  
Nutthavich Thouchprasitchai ◽  
...  

The synthesis of carbon nanoparticles (Cn) and oxygen-doped nanocarbon (OCn) was successfully done through a one-step synthesis by the solution plasma process (SPP). The Cn and OCn were nitrogen-doped by nitridation under an ammonia atmosphere at 800 °C for 2 h to yield NCn and NOCn, respectively, for carbon dioxide (CO2) adsorption. The NOCn exhibited the highest specific surface area (~570 m2 g−1) and highest CO2 adsorption capacity (1.63 mmol g−1 at 25 °C) among the synthesized samples. The primary nitrogen species on the surface of NOCn were pyridinic-N and pyrrolic-N. The synergistic effect of microporosity and nitrogen functionality on the NOCn surface played an essential role in CO2 adsorption enhancement. From the thermodynamic viewpoint, the CO2 adsorption on NOCn was physisorption, exothermic, and spontaneous. The NOCn showed a more negative enthalpy of adsorption, indicating its stronger interaction for CO2 on the surface, and hence, the higher adsorption capacity. The CO2 adsorption on NOCn over the whole pressure range at 25–55 °C best fitted the Toth model, suggesting monolayer adsorption on the heterogeneous surface. In addition, NOCn expressed a higher selective CO2 adsorption than Cn and so was a good candidate for multicycle adsorption.


2019 ◽  
Vol 19 (3) ◽  
pp. 475-483 ◽  
Author(s):  
Muvumbu Jean-Luc Mukaba ◽  
Alechine Emmanuel Ameh ◽  
Chuks Paul Eze ◽  
Leslie Felicia Petrik

Author(s):  
Joanna Srenscek-Nazzal ◽  
Urszula Narkiewicz ◽  
Antoni W. Morawski ◽  
Rafal J. Wróbel ◽  
Beata Michalkiewicz

2020 ◽  
Vol 294 ◽  
pp. 109871 ◽  
Author(s):  
Satriyo Krido Wahono ◽  
Joseph Stalin ◽  
Jonas Addai-Mensah ◽  
William Skinner ◽  
Ajayan Vinu ◽  
...  

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