Development of intensified flat-plate packed-bed solar reactors for heterogeneous photocatalysis

Autor(es)

Ramos, Bruno ^{[1, 2]} ; Carneiro, Joao Gabriel M. ^[1] ; Nagamati, Leandro Issamu ^[1] ; Teixeira, Antonio Carlos S. C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Polytech Sch, Dept Chem Engn, Res Grp Adv Oxidat Proc AdOx, BR-05088000 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Polytech Sch, Dept Met & Mat Engn, Lab Ceram Proc, BR-05088000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 28, n. 19, SI JAN 2021.
• Citações Web of Science: 0

Resumo

Solar-driven photocatalysis is a promising water-cleaning and energy-producing technology that addresses some of the most urgent engineering problems of the twenty-first century: universal access to potable water, use of renewable energy, and mitigation of CO2 emissions. In this work, we aim at improving the efficiency of solar-driven photocatalysis by studying a novel reactor design based on microfluidic principles using 3D-printable geometries. The printed reactors had a dimensional accuracy of 97%, at a cost of less than \$1 per piece. They were packed with 1.0-mm glass and steel beads coated with ZnO synthesised by a sol-gel routine, resulting in a bed with 46.6% void fraction (reaction volume of ca. 840 mu L and equivalent flow diameter of 580 mu m) and a specific surface area of 3200 m(2) m(-3). Photocatalytic experiments, under sunlight-level UV-A irradiation, showed that reactors packed with steel supports had apparent reaction rates ca. 75% higher than those packed with glass supports for the degradation of an aqueous solution of acetaminophen; however, they were strongly deactivated after the first use suggesting poor fixation. Glass supports showed no measurable deactivation after three consecutive uses. The apparent first-order reaction rate constants were between 1.9 and 9.5 x 10(-4) s(-1), ca. ten times faster than observed for conventional slurry reactors. The mass transfer was shown to be efficient (Sh > 7.7) despite the catalyst being immobilised onto fixed substrates. Finally, the proposed reactor design has the merit of a straightforward scaling out by sizing the irradiation window according to design specifications, as exemplified in the paper. (AU)

• Processo FAPESP: 18/21271-6 - Degradação de poluentes de interesse emergente por luz solar: fotorreatores e tratamentos inovadores
• Beneficiário: Antonio Carlos Silva Costa Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular