Recently, a Tianjin University research team led by Professor Wang Zhi and Professor Michael D. Guiver of the Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) at Tianjin University developed a highly permeable mixed-matrix membrane for CO2 separation. This research result has been published by the Angewandte Chemie International Edition (Angew. Chem. Int. Ed. DOI：10.1002/ange.201603211) and as a Press Release. (https://wiley.altmetric.com/details/9076264,http://www.aiweibang.com/yuedu/129604892.html)
The research has found an important means of separating CO2 from CO2 mixtures such as flue gas, natural gas, biogas and synthesis gas to achieve energy gas purification and greenhouse gas reduction. Compared to other separation methods, membrane separation has the advantage of low energy consumption and easy operation, so attracting wide-spread attention from researchers at home and abroad.
The researchers first stuck polyvinylamineacid chains onto a porous polymer substrate. These polymer chains are aligned perpendicular to the substrate. Between the chains, the researchers introduced nanoparticles of montmorillonite in which they had previously replaced the usual calcium ions with sodium ions. A special coupling reagent was used to bind the mineral layers with the polymer chains into a mixed matrix. This method maintains the layers, and thus their channels, parallel to the polymer chains. The result is an ultrathin membrane with straight channels that can be used for transport. The OH groups in the channel walls interact with the acidic CO2, facilitating its transport. The permeability of the membrane for CO2 is thus significantly higher than for nitrogen, methane, or hydrogen, which allows the CO2 to be separated from mixtures.
Professor Wang's team made a long-term commitment to membrane for CO2 separation research, supported by the National Natural Science Foundation of China, National 973 Program, National 863 Program, Tianjin Science and Technology Support Program and Business Cooperation Projects. They developed a complete technology chain that formed an integrated membrane material design and preparation with a membrane device. Relevant research achievements have been issued for 46 papers in the International Journals such as Angewandte Chemie International Edition, Advanced Materials, AIChE Journal, Energy & Environmental Science and the Journal of membrane Science, and they have 18 authorized national invention patents, for setting up the different sizes of CO2 separation membranes and membrane modules test devices as well as membrane separation biogas decarburization industrial test devices.
