Monoethanolamine (MEA) is the benchmark solvent for the capture of carbon dioxide from both natural gas and flue gas streams. Despite its effectiveness in absorbing CO2, this solvent can react with impurities in the gas stream to form heat stable salts and other degradation products. These impurities can cause problems such as an increase in solvent viscosity and corrosion of the operating units. Thus, a number of approaches have been considered to mitigate the occurrence of these problems. In this paper, the use of electrodialysis as an online MEA reclamation process in a postcombustion CO2 capture facility is investigated. The study shows that high heat stable salts removal can be achieved with a high MEA recovery. However, it is necessary to limit the current density, particularly at lower salt concentrations, to reduce water splitting. The stability of the commercial ion-exchange membranes in the highly alkaline solvent is also investigated. The results show that the membranes are stable upon exposure to 30 wt % MEA for at least 4.5 months.

The cement industry is a significant source of CO 2 emissions for the non-power sector. Carbon capture and storage has been proposed as a strategy to mitigate these CO 2 emissions. The high CO 2 partial pressure of the cement kiln flue gas enables more options than in other post-combustion capture scenarios. Here, three distinct process designs for membrane gas separation are simulated for the capture of CO 2 from cement kiln flue gas. The first design is based on a standard natural gas processing flowsheet and includes two membrane stages with a permeate recycle from the first stage. The second design uses a single membrane stage with downstream compression and cooling to achieve the necessary purity. The final design incorporates three membrane stages with similar downstream compression and cooling. It was found that the CO 2 /N 2 selectivity of the membrane strongly influenced the performance of all three processes. The third design achieved the lowest energy demand of 1.2 MJ/kg of CO 2 captured for membranes with CO 2 /N 2 selectivity above 50. Below a selectivity of 25 the second design with a single membrane stage had the lowest energy demand. However, a different trend was observed with cost of capture, where below a CO 2 /N 2 selectivity of 25 the second design provided the lowest cost of capture while above this selectivity the first design was cheapest. This design could provide a cost of capture of US$ 74 per tonne of CO 2 avoided, based on current state-of-the art membrane permselectivity, which is competitive with solvent absorption carbon capture technologies. However, calcium looping and oxyfuel combustion would appear to have lower costs in this scenario.

Compartmentalized microfluidic devices are becoming increasingly popular and have proven to be valuable tools to probe neurobiological functions that are inherently difficult to study using traditional approaches. The ability of...