The cement industry is responsible for approximately 5% of global anthropogenic carbon dioxide emissions emitting nearly 900 kg of CO2 for every 1000 kg of cement produced. Effective control strategies to mitigate these emissions are discussed and a mathematical programming model able to suggest the best cost effective strategy is outlined. Control costs consisting of operating and investment costs along with the efficiency of control options are taken into account in the model. A representative case study from the cement industry was considered in order to illustrate the use of the model in giving optimal control strategies. Efficiency improvement measures were found to be effective options for reduction targets up to 10 %. The model suggested that fuel switching and carbon capture must be considered at reduction targets higher than 10%. The cost of cement production was shown to increase dramatically with an increase in reduction target.

Multi-walled carbon nanotubes (CNTs) and zeolitic imidazole frameworks (ZIF-301) were synergistically incorporated into glassy polysulfone (PSF) to prepare mixed-matrix membranes (MMMs) to separate CO₂ from post combustion flue gas. The flexible MMMs rendering consistent distribution and improved adhesion of nanofillers with the polymer matrix were hydrothermally stable under wet conditions. Gas sorption analysis along with dry and wet gas permeation experiments showed that both CO₂ permeability and CO₂/N₂ selectivity of MMMs were improved owing to the synergistic effect of nanofillers. The MMM filled with 18 wt % ZIF-301 nanofillers and 6 wt % CNTs showed an optimum separation performance by providing a CO₂ permeability of 19 Barrers with a CO₂/N₂ selectivity of 48. The CO₂ separation performance of MMMs prepared in this work was found to be better than those of already existing hydrothermally stable MMMs.