Spray drying of zinc-based precursors: study of the variation of process parameters in the properties of the material

• Grant number: 19/09626-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: July 31, 2020
• Field of knowledge: Engineering - Chemical Engineering - Industrial Operations and Equipment for Chemical Engineering
• Principal Investigator: Lívia Chaguri e Carvalho
• Grantee: Paulo Henriques de Faria Neto
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

The spray-drying process consists of organic or aqueous evaporating solutions, using an atomizer nozzle, into a chamber with controlled temperature, flow and air pressure. The fluids (solution, emulsion, suspension or dispersion) converted into powders dry are generally, product of uniform morphology. A high quality product is achieved, when a good combination of the adjustable parameters of the equipment. The feed formulation also plays an important role in ensuring a high quality product, so the combination of its components is also interesting. Some methods to produced precursors and, subsequently, zinc oxide (ZnO) photocatalysts such as vapor deposition, hydrothermal method, Sol-Gel method, precipitation method, among others, gives rise to products with different particles shapes, sizes and spatial structure. In most of these methods, a drying step is required and generally, it is occurs in oven. The aim of this research project is to study the influence of the spray drying parameters on the physicochemical properties of the precursor (ZnO.nH2O/xerogel of tannin-formaldehyde) and the photocatalyst (ZnO/xerogel of carbon). The change of the drying form can contribute to the improvement of the ZnO particle morphology, which can lead to a product with better photocatalytic sensitivity. This material is of fundamental importance, since it is indicate as one of the most efficient photocatalysts in the decontamination of aqueous effluents due to its higher efficiency in H2O2 generation, higher reaction rates and mineralization, higher number of active sites and high surface reactivity. Project resources required were provide by FAPESP (project number 2017/03428-2.