- Instituto Superior Técnico - IST
- University of Lisbon
- Department of Chemical Engineering
- Centro de Recursos Naturais e Ambiente - CERENA
- Fundação para a Ciência e a Tecnologia
Selective adsorption of gases and vapors by adsorbent materials can be used industrially for the recovery of valuable products and separation of mixtures. In fact, most of the energy spent in a chemical plant is devoted to the recovery and purification of the desired products. The key for a successful separation by adsorption is the adsorbent material and its selectivity. In the past years, the development of adsorbents for the biogas and natural gas upgrading, organic vapors separation and more recently for ethane/ethylene separation has been actively explored.
Adsorbent materials can be used to store gases inside their pores under pressures significantly below their storage pressure in normal containers and cylinders. This is useful for the development of new storage vessels and transporting systems for combustible gases, namely methane, with more favorable operating conditions. Another useful application of the storage gas ability of adsorbents is the storage of nitric oxide for possible therapeutic applications with the advantage of a target delivery at the desired location in the human body. These possibilities have been explored in recent works and are being under development in ongoing projects.
During synthesis and preparation, adsorbents are commonly obtained as fine powders, which pose some difficulties for their application in gas and liquid flows. Thus, often the adsorbents have to be shaped into more useful forms before real life applications. Composite adsorbent materials based on polyurethane foams as supporting media for adsorbents have been an interest since Ph.D. works. Recently, polyurethane foams have been used as templates of the synthesis of adsorbent materials with the shape of foams. More recently, polyurethane rubber composites are being studied to develop applications for granular rubber from end-of-life tires. The binding of adsorbents powders with clays is also a topic of interest.