Impact of the biogas impurities on the quality of the precipitated calcium carbonate in the regenaration stage of a chemical absorption biogas upgrading unit
Combining Carbon Capture and Storage (CCS) with producing competitive secondary raw materials is key to decarbonizing industry and reducing resource extraction. Biogas upgrading to biomethane stand out as an alternative, but a significant gap remains in integrating this process within a circular eco...
| Autores: | , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/387623 |
| Acesso em linha: | http://hdl.handle.net/10261/387623 https://api.elsevier.com/content/abstract/scopus_id/85201720256 |
| Access Level: | acceso abierto |
| Palavra-chave: | Aqueous carbonation process Biogas upgrading Carbon capture Chemical absorption CO2 utilization Energy recovery http://metadata.un.org/sdg/13 http://metadata.un.org/sdg/9 http://metadata.un.org/sdg/7 Ensure access to affordable, reliable, sustainable and modern energy for all Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation Take urgent action to combat climate change and its impacts |
| Resumo: | Combining Carbon Capture and Storage (CCS) with producing competitive secondary raw materials is key to decarbonizing industry and reducing resource extraction. Biogas upgrading to biomethane stand out as an alternative, but a significant gap remains in integrating this process within a circular economy framework. This issue has been recently addressed by a process that integrates biogas upgrading via caustic absorption with the production of Precipitated Calcium Carbonate (PCC) and the recovery of sodium hydroxide from waste brine solution using membrane technologies. The profitability of this approach depends on the quality of the PCC, a critical factor that this work addresses. By characterizing PCC is determined whether trace compounds in biogas contaminate the PCC and potentially affect its commercial value. It also examines the CO2 absorption process and analyzes the aqueous samples from the filtration phase of the PCC slurry. Results confirm the high purity of PCC obtained from biogas treatment using Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The analyses show that the PCC is pure calcium carbonate, mainly in the stable calcite form, with a typical tetrahedral morphology and no detectable impurities. Characterization of aqueous solutions revealed organic trace compounds from biogas, with TOC concentrations of 9.7 (± 6.4) and 16.0 (± 8) mg C/l. Silicon measurements showed similar concentrations in the absorbent solution and filtrated PCC slurry. Additionally, ammonia escapes as gas, and hydrogen sulfide in the biogas likely contributed to sulfate salt formation. Analysis of the CO₂ absorption shows a first-order reaction with OH-, where the amount of CO₂ absorbed (46.3–50.0 g) closely matches the theoretical value of 48 g. The study reveals that most of the biogas impurities dissolve into the aqueous solution, being crucial for future studies and downstream membrane treatments, and the PCC is unaffected by these impurities with a purity suitable for commercial applications. |
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