Carbon adsorbents for CO2 capture from bio-hydrogen and biogas streams: Breakthrough adsorption study
The biological production of H2 by dark fermentation is being extensively investigated due to the great potential of the two-phase hydrogen/methane fermentation process for recovering energy from carbohydrate-rich wastes. However, the purification of the bio-hydrogen and biogas obtained is needed to...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/112334 |
| Acceso en línea: | http://hdl.handle.net/10261/112334 |
| Access Level: | acceso abierto |
| Palabra clave: | Bio-hydrogen Biomass Dark fermentation Activated carbon CO2 capture Breakthrough tests |
| Sumario: | The biological production of H2 by dark fermentation is being extensively investigated due to the great potential of the two-phase hydrogen/methane fermentation process for recovering energy from carbohydrate-rich wastes. However, the purification of the bio-hydrogen and biogas obtained is needed to produce high-purity H2 and CH4 streams appropriate for industrial application. In this study, the performance of three activated carbons (No1KCla-600, No1KClb-1000 and No2OS-1000), synthesized from phenol–formaldehyde resins, as potential adsorbents for CO2 capture from bio-hydrogen and biogas streams has been evaluated under dynamic conditions. Adsorption–desorption cycles by means of temperature swings were conducted at ambient temperature and atmospheric pressure with CO2/H2 (40/60 and 70/30 vol.%) and CO2/CH4 (50/50 vol.%) binary gas mixtures in a purpose-built fixed-bed set-up. The performance of the resin-derived carbons to separate CO2 was superior to that of reference commercial carbons in terms of CO2 uptake, breakthrough time and column efficiency. These adsorbents presented high CO2/H2 and CO2/CH4 selectivity values, were easily completely regenerated and did not show capacity decay after multiple cycling. Breakthrough capacities reached 2.11 and 2.03 mmol g−1 at 25 °C for 70/30 CO2/H2 and 50/50 CO2/CH4, respectively. The No2OS-1000 adsorbent, produced from phenol–formaldehyde resin and olive stones (20:80 wt.), gave the greatest values of CO2 capture capacity on a volumetric basis and CO2/CH4 selectivity, which may be advantageous to biogas purification applications because it reduces the size of the necessary equipment. |
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