Improvement of the Manufacturing Process of a Novel Microfiltration Ceramic Membrane

• Autor(a) principal: Azevedo, Joana Filipa Gingeira Jardim de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/85389
• topic: ceramic membrane; microfiltration; lapping; microstructure and permeability; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

Membranes are highly selective barriers that are used to separate particles and/or molecules from a fluid, purifying it. The selectivity of membranes depends on pore size, composition, electrochemical properties and/or the properties of the media being separated. This technology has been gaining importance over the last few years, particularly for its application in several different industries such as food processing, biotechnology, pharmaceutical and research industries. However, current microfiltration membrane technologies are inefficient and/or too expensive. Smart Separations Ltd, a startup funded in 2013 in London (England), has developed an innovative patented technology, that allows the production of microfiltration flat ceramic membrane with conically-shaped pores that cross through them. These could address current hurdles, whilst offering a wide range of applications through easy pore size manipulation. This research project aims at optimising the manufacturing process of Smart Separations’s membranes, specifically the lapping operation, which is the critical stage where truly flat and smooth membranes are obtained, in addition to the tight control of the pore sizes. It was also important to characterise the membranes and confirm the reliability of the in-house characterisation techniques. The manufacturing process of the membranes was optimised by studying the influence of some parameters in the lapping operation, such as time and cut thickness. The studied membranes were then characterised based on different parameters, such as their microstructure (e.g. pore sizes, pore size distribution, pore geometry and connectivity), gas permeability and functionality (dust retention). After the lapping operation, membranes were observed on an optical microscope and SEM, and the results were analysed using Image Pro Premier 9.1. Porometry results along with the in-house permeability tests were compared to data on the same samples provided by a subcontractor company, Porometer, to assess their accuracy. After interpreting the lapping results, it was concluded that the lapping technique used wasn’t yet accurate enough to determine the exact lapping parameters to produce specific pore-sized membranes. In-house permeability tests are accurate according to Porometer’s data, although pore size results don’t match up due to the lapping not being accurate enough and the limitation of the selected area by imaging analysis. Smart Separations is currently developing an automated lapping fixture that will improve the lapping accuracy to better analyse the effects of each different parameter in production.