Produção da farinha de mandioca no Nordeste paraense.

Cópia de trabalho editado em CD-ROM

Extração madeireira na Amazônia: manejo sustentado ou silvicultura.

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Caracterização do sistema de produção da cultura do caupi no nordeste paraense.

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A pequena agricultura familiar paraense: uma abordagem econômica e sociológica.

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Rapid synthesis of MCM-41 and SBA-15 by microwave irradiation: promising adsorbents for CO2 adsorption

It is known that the world scenario is one of constant search for sustainable technologies that can reduce the emission of carbon dioxide (CO2) in the atmosphere. This is because CO2 is seen as the main responsible for the increase in the generation of greenhouse gases, which leads to global warming and climate change. The development of efficient adsorbents for CO2 capture is a current challenge. MCM-41 and SBA-15 were synthesized in a microwave reactor and used as adsorbents in this work. Microwave irradiation presents itself as an easy synthesis strategy with less preparation time and energy requirement. The silica synthesis period was extremely reduced (1 h) at a temperature of 60 and 80 °C in the microwave reactor, obtaining silica with good textural and chemical properties. The CO2 adsorption isotherms were performed at 0, 25, and 40 °C at 1 bar. The MCM-41 and SBA-15 present favorable results for CO2 capture processes, showing that pure silica synthesized by microwave already obtains promising results, reaching a maximum adsorption capacity of 2.16 mmol g−1 (1 bar—0 °C) and a good fit for the Langmuir, DsL and Toth models. Furthermore, to increase CO2 adsorption, the mesoporous silica was also modified via impregnation with branched polyethylene diamine (PEI) or tetraethylenepentamine (TEPA). It is worth mentioning that microwave irradiation reduced the synthesis steps and improved the properties and adsorption capacity of the silica. This work opens new opportunities in the efficient preparation of materials that require optimizing the adsorbent synthesis process.The authors thank you to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, National Council for Scientific and Technological Development, Brazil) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Higher Education Personnel Improvement Coordination, Brazil, CAPES—financing code 001) for financial support. This research was also funded by the Ministry of Science, Innovation and Universities (Spain), Grants Nos. RTI2018-099668-B-C22 and PID2021-126235OB-C32, and projects UMA18-FEDERJA-126 and P20_00375 of Junta de Andalucía and FEDER funds. // Funding for open access publishing: Universidad Málaga/CBUA

Introdução de mudanças tecnológicas em sistemas de produção familiares: o caso da Associação dos Pequenos e Microprodutores Rurais do Panela - Irituia-PA.

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