Effect of ultramicropores on the mechanisms of H2S retention from biogas

Oliveira, Jorge Luiz Bezerra de; Nascimento, Beatriz Oliveira; Gonçalves, Daniel V.; Santiago, Rafaelle Gomes; Lucena, Sebastião M. P.; Azevedo, Diana C. S.; Bastos‐Neto, Moises

doi:10.1016/j.cherd.2019.12.019

Cited by 12 publications

(4 citation statements)

References 41 publications

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“…Thus, tests for each sample and the obtained H 2 S retention amount were performed according to the procedure detailed elsewhere. 63,64 2.6. CO 2 , CH 4 , and H 2 O Adsorption Measurements.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, for systems with relative low mass transfer resistance, the breakpoint time does not differ significantly from the stoichiometric time, which leads to a breakthrough curve with the shape of a step function. Thus, tests for each sample and the obtained H 2 S retention amount were performed according to the procedure detailed elsewhere. , …”

Section: Methodsmentioning

confidence: 99%

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H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

Sousa

Amâncio

Morales-Ospino

et al. 2021

Ind. Eng. Chem. Res.

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Hollow microspheres of silica were synthesized and functionalized with amino groups to enhance carbon dioxide adsorption. Functionalization was intended to provide acid–base interaction between CO2 and amine groups. Samples were characterized by N2 adsorption/desorption isotherms at 77 K, X-ray diffraction, scanning electronic microscopy, and Fourier transform infrared spectroscopy. For adsorption experiments, both volumetric and gravimetric devices were used to quantify adsorbed CO2 as a function of pressure and temperature. CO2 adsorption isotherms obtained for the amine grafted silica confirmed the coexistence of chemical and physical adsorption sites within the material, which means that CO2 binding occurs not only by physical mechanisms on micropores but also due to interactions with amino groups. The saturation of the adsorbent with H2S to simulate the purification of natural gas or biogas slightly diminishes CO2 adsorption capacity due to competition between CO2 and H2S for amine sites. Preadsorption of H2O on the H2S saturated adsorbent did not lead to improvements in CO2 uptake. On the contrary, preloaded H2O combined with H2S seems to block some of the chemical sites involved in CO2 adsorption.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

Sousa

Amâncio

Morales-Ospino

et al. 2021

Ind. Eng. Chem. Res.

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“…The same phenomenon was observed for other porous adsorbents as well, such as silica gel and activated carbons. Therefore, physisorption cannot gratify demands for highly efficient CO 2 / H 2 S separation in comparison to chemisorption,57 where strong chemical bonds (covalent bonds) can be formed between the metal and H 2 S 58. 2.2.4.…”

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confidence: 99%

Adsorption of Hydrogen Sulfide at Low Temperatures Using an Industrial Molecular Sieve: An Experimental and Theoretical Study

et al. 2021

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In the work presented herein, a joint experimental and theoretical approach has been carried out to obtain an insight into the desulfurization performance of an industrial molecular sieve (IMS), resembling a zeolitic structure with a morphology of cubic crystallites and a high surface area of 590 m 2 g –1 , with a view to removing H 2 S from biogas. The impact of temperature, H 2 S inlet concentration, gas matrix, and regeneration cycles on the desulfurization performance of the IMS was thoroughly probed. The adsorption equilibrium, sorption kinetics, and thermodynamics were also examined. Experimental results showed that the relationship between H 2 S uptake and temperature increase was inversely proportional. Higher H 2 S initial concentrations led to lower breakpoints. The presence of CO 2 negatively affected the desulfurization performance. The IMS was fully regenerated after 15 adsorption/desorption cycles. Theoretical studies revealed that the Langmuir isotherm better described the sorption behavior, pore diffusion was the controlling step of the process (Bangham model), and that the activation energy was 42.7 kJ mol –1 (physisorption). Finally, the thermodynamic studies confirmed that physisorption predominated.

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“…Additionally, due to its corrosive and poisonous nature, hydrogen sulfide (H 2 S) is another gas that needs removal during the energy generation process. Therefore, significant efforts are being undertaken to develop technologies to curb CO 2 emissions and efficiently remove H 2 S. − In the past 20 years, the most promising and researched materials used for adsorption of harmful gases are zeolites, activated carbons, metal organic frameworks, and amine-functionalized mesoporous silica (silica gels, MCM-41, and SBA-15) due to their favorable porous properties. − …”

Section: Introductionmentioning

confidence: 99%

SBA-15 Functionalized with Amines in the Presence of Water: Applications to CO₂ Capture and Natural Gas Desulfurization

Anyanwu

Wang

Yang

2021

Ind. Eng. Chem. Res.

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Conventional and pore expanded SBA-15 were amine-grafted under dry and wet conditions using N 1-(3-trimethoxysilylpropyl)diethylenetriamine. The effects of pore properties and gas hourly space velocity (GHSV) as well as the CO2 and H2S capture performance were investigated, and the results indicated that pore expanded SBA-15 displayed the best performance. Clumping and agglomeration of SBA-15 were observed for conventional SBA-15 under wet grafting conditions due to interparticle polymerization of amines after pores are completely filled. This phenomenon was not observed for pore expanded SBA-15, resulting in viable adsorbents with greater amounts of grafted amines. Pore expanded SBA-15 exhibited the highest CO2 capacity (3.27 mmol/g), which to the best of our knowledge is the largest for amine-grafted adsorbents. It also exhibited high amine efficiency (0.39 mol CO2/mol N) and faster uptake rates compared to conventional SBA-15 due to enhanced amine accessibility. For direct air capture, higher GHSV values result in lower breakthrough CO2 capacities and the breakthrough CO2 capacity of wet grafted pore expanded SBA-15 is more dependent on GHSV than that of dry grafted pore expanded SBA-15 due to diffusion resistance. Last, conventional SBA-15 displayed a marginally lower H2S adsorption capacity compared to pore expanded SBA-15, suggesting that diffusion resistance does not play a significance role during H2S adsorption. These results suggest the consideration of wet grafted pore expanded mesoporous siliceous supports for the design of promising adsorbents for the capture of CO2 and the removal of H2S from natural gas.

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Effect of ultramicropores on the mechanisms of H2S retention from biogas

Cited by 12 publications

References 41 publications

H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

Adsorption of Hydrogen Sulfide at Low Temperatures Using an Industrial Molecular Sieve: An Experimental and Theoretical Study

SBA-15 Functionalized with Amines in the Presence of Water: Applications to CO₂ Capture and Natural Gas Desulfurization

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Effect of ultramicropores on the mechanisms of H2S retention from biogas

Cited by 12 publications

References 41 publications

H2S and H2O Combined Effect on CO2 Capture by Amino Functionalized Hollow Microsphere Silicas

H2S and H2O Combined Effect on CO2 Capture by Amino Functionalized Hollow Microsphere Silicas

Adsorption of Hydrogen Sulfide at Low Temperatures Using an Industrial Molecular Sieve: An Experimental and Theoretical Study

SBA-15 Functionalized with Amines in the Presence of Water: Applications to CO2 Capture and Natural Gas Desulfurization

Contact Info

Product

Resources

About

H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

H₂S and H₂O Combined Effect on CO₂ Capture by Amino Functionalized Hollow Microsphere Silicas

SBA-15 Functionalized with Amines in the Presence of Water: Applications to CO₂ Capture and Natural Gas Desulfurization