CS SERIES (chemically stable) MEMBRANE ELEMENTS
Ultrafiltration (UF) and nanofiltration (NF) polymeric membranes can be modify with specific surface treatments in order to change the polymer, use of particular glues and materials they can now be made resistant to solutions for which in the past referred to filtration processes. In particular, Sepra, in collaboration with its suppliers, is working hard to offer a range of products that we want to define as “chemically and thermally stable UF and NF membranes”.
These membranes represent a technological breakthrough for the purification and recovery of acid, alkaline or solvent-based solutions for the pharmaceutical, fine chemical, textile and food industries. This is a particularly topical topic, with a view to moving from an industry that consumes resources towards a circular economy that re-uses resources.
Filtration of Alkaline Solutions:
Applications range from the recovery of exhausted alkalis in production processes in industries that produce chemicals, to the textile industry, to the recovery of solutions resulting from the bleaching of sugar (which allows the reuse of up to 95% of sodium hydroxide).
The purification of the basic solution can be done with ultrafiltration or nanofiltration membranes, to be chosen according to the impurity or product to be removed, with cuts ranging up to 100 Da.
Filtration of Solvent based solutions:
Until a few years ago, the solvent membrane treatment was done with inorganic membranes of the ceramic type. In recent years, polymeric membranes have also appeared for the treatment of solvent-based solutions, where typical applications are in the pharmaceutical industry and for the recovery of paints such as:
• Recovery of antibiotics and pharmaceutical intermediates (such as peptides)
• Recovery of pigments, dissolved chemicals and catalysts
• Recycling of hydrocarbons in cleaning processes
These membranes are compatible with the most common solvents such as: acetonitrile, acetone, methylene chloride, toluene and various alcohols. Different molecular cuts are available from ultrafiltration to nanofiltration resistances with MWCO ranging up to 100 Da.
Filtration of Acid Solutions:
The main market for these membranes refers to the mining industry for the recovery of metals such as (copper, zinc, cobalt, molybdenum, tungsten, uranium, gold). The recovery of exhausted acids is another typical application, for example the recovery of acids in leaching operations.
The process on acid-based solutions can be done with UF and NF membranes with cuts ranging up to 100Da.