Adsorption Equilibrium of Alkanes on a High Surface Area Activated Carbon Prepared from Brazilian Coconut Shells

Walton, Krista S.; Cavalcante, Célio L.; LeVan, M. Douglas

doi:10.1007/s10450-005-4901-3

Cited by 29 publications

(18 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Temperature dependency is also built into this model. Therefore, the parameters given for alkanes adsorption on BPL carbon (Walton et al, 2004) and coconut shell carbon (Walton et al, 2005) are applicable to the entire operating range considered here. Pure-component isotherms and model predictions for methane, ethane, and n-butane on both BPL and BCA carbon at 298 K are shown in Figure 2.…”

Section: Multicomponent Adsorption Modelmentioning

confidence: 98%

“…Pure-component isotherms and model predictions for methane, ethane, and n-butane on both BPL and BCA carbon at 298 K are shown in Figure 2. Isotherms for these and other components and mixtures at different temperatures are given elsewhere (Walton et al, 2004(Walton et al, , 2005. BCA carbon has higher capacities for butane than BPL carbon.…”

Section: Multicomponent Adsorption Modelmentioning

confidence: 99%

See 1 more Smart Citation

Natural gas storage cycles: Influence of nonisothermal effects and heavy alkanes

Walton

LeVan

2006

Adsorption

Self Cite

View full text Add to dashboard Cite

A mathematical model is developed for examining the influence of nonisothermal effects and accumulation of heavy alkanes on natural gas storage cycles. The model is solved for the charge and discharge steps of the cycle. This is the first study to solve the natural gas storage problem for a nonisothermal charge of natural gas containing impurities. We examine both adiabatic and isothermal operation of natural gas and pure methane storage cycles on BPL carbon and an activated carbon prepared from coconut shells. Our simulations show for both carbons that the adiabatic gas storage cycles operate under subcooled conditions with respect to the feed temperature due to long discharge times and the desorption heat. It is also shown that degradation of gas storage performance due to impurities depends more on selectivity of the material for heavy alkanes than on adsorption capacities.

show abstract

Section: Multicomponent Adsorption Modelmentioning

confidence: 98%

Section: Multicomponent Adsorption Modelmentioning

confidence: 99%

Natural gas storage cycles: Influence of nonisothermal effects and heavy alkanes

Walton

LeVan

2006

Adsorption

Self Cite

View full text Add to dashboard Cite

show abstract

“…Some studies have suggested that methane adsorbed to organic materials can be released into methanefree air at steady rates for periods of days to weeks (Zhang and Krooss, 2001;Cheng and Huang, 2004). Unfortunately, few data are available for low-pressure methane adsorption capacities of non-activated compounds, and extrapolation from available adsorption isotherms to a low pressure range is limited due to the very strong pressure-dependence of adsorption at low pressures (Shao et al, 2004;Walton et al, 2005;Garcia-Perez et al, 2007;Saha et al, 2007). Kirschbaum et al (2007) estimated an adsorption potential of about 40 000 ngCH 4 kgDW −1 based on the adsorption characteristics of plant cell walls of coconut charcoal when they assumed a simple linear dependence of adsorption on methane partial pressure.…”

Section: Reported a New Finding Thatmentioning

confidence: 99%

No detectable aerobic methane efflux from plant material, nor from adsorption/desorption processes

Kirschbaum

Walcroft

2008

Biogeosciences

View full text Add to dashboard Cite

Abstract. In early 2006, Keppler et al. (Nature, 439:187-191) reported a novel finding that plant leaves, and even simple organic materials, can release methane under aerobic conditions. We investigated here whether the reported methane release might simply arise from methane desorption from sample surfaces after prior exposure to higher methane concentrations. We exposed standard cellulose filter papers (i.e. organic material with a high surface area) to atmospheric methane concentration and then transferred them to a low-methane atmosphere. Our results suggest that any desorption flux was extremely small (−0.0001±0.0019 ngCH 4 kgDW −1 s −1 ) and would play no quantitatively significant role in modifying any measured methane fluxes.We also incubated fresh detached leaves of several species and intact Zea mays seedlings under aerobic and low-light conditions. After correcting for a small measured methane influx into empty chambers, measured rates of methane emission by plant materials were zero or, at most, very small, ranging from −0.25±1.1 ngCH 4 kgDW −1 s −1 for Zea mays seedlings to 0.10±0.08 ngCH 4 kgDW −1 s −1 for a mixture of freshly detached grasses. These rates were much smaller than the rates originally reported by Keppler et al. (2006).

show abstract

“…The adsorption of natural gas in porous materials, in which case the gas may be stored (ANG) under moderate pressures (between 3.5 and 4.0 MPa), has been studied as an alternative for its storage and transport (Parkyns et al 1995;Sun et al 1996;Lozano-Castelló et al 2002a, 2002bAzevedo et al 2007;Bastos-Neto et al 2005;Walton et al 2005;Zhang et al 2008;Prauchner and Rodriguez-Reinoso 2008). According to Cook et al (1999), activated carbon (AC) is the most adequate material for NG storage systems due to its textural properties-such as surface area and micropore volume-which may be tailored according to a given adsorbate, besides being hydrophobic and having high affinity for organic substances.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of methane in activated carbons obtained from coconut shells using H3PO4 chemical activation

et al. 2009

Self Cite

View full text Add to dashboard Cite

Activated carbon samples from coconut shells (Brazilian coconut species "Coco da Baía") were prepared by chemical activation with phosphoric acid as the activating agent. Samples were characterized by nitrogen adsorption isotherms at 77 K. Some samples were randomly chosen in order to perform methane adsorption experiments under pressures between 1 and 60 bar at 303 K. A close relationship between surface area, micropore volume and methane adsorption capacity for carbons prepared from the same starting material was observed. The highest methane storage capacity in the tested samples was found to be 95 v/v at 303 K and 35 bar, which is comparable to results obtained for commercial samples indicated for this application. A moderate concentration of phosphoric acid (around 35%) seems to favor high surface areas, micropore volumes and, hence, gas storage capacity. The inclusion of an acid wash step before carbonization and the use of inert gas flow during carbonization also seem to enhance the development of porosity. This result suggests that activated carbons prepared from "Coco da Baía" by chemical activation with phosphoric acid have potential to be used as a storage media for natural gas.

show abstract

Adsorption Equilibrium of Alkanes on a High Surface Area Activated Carbon Prepared from Brazilian Coconut Shells

Cited by 29 publications

References 13 publications

Natural gas storage cycles: Influence of nonisothermal effects and heavy alkanes

Natural gas storage cycles: Influence of nonisothermal effects and heavy alkanes

No detectable aerobic methane efflux from plant material, nor from adsorption/desorption processes

Adsorption of methane in activated carbons obtained from coconut shells using H3PO4 chemical activation

Contact Info

Product

Resources

About