用于从空气中或烟囱中捕获二氧化碳的设备通常采用一种可逆过滤器的工作原理。
Equipment to capture carbon dioxide from ambient air or smokestacks generally works through a sort of reversible filter.
空气被引入含有吸收二氧化碳的颗粒或液体中，随后这些含有二氧化碳的物质经过加热等处理，释放出二氧化碳，从而可以被收集起来。类似的操作也可以在更小的尺度上进行——例如在电池内部。
Air is passed through granules or a liquid that absorbs the CO2, then that CO2-loaded substance undergoes a process (usually heating) that causes it to let go of all that CO2. The resulting gas can be collected in a separated stream. It’s also possible to do a similar sort of operation on a smaller scale—like inside a battery.
由特拉华大学的James Buchen领导的团队进行的一项新研究展示了一种基于电池的电化学碳捕获技术，他们认为这种技术比之前的尝试更为可行。这种技术可能所需的能量更少，因此成本也更低。
A new study from a team led by James Buchen of the University of Delaware demonstrates an example of a battery-based electrochemical carbon-capture technique that they say is more viable than previous attempts. It has the potential to require less energy—and therefore be cheaper—than the reversible-filter designs that currently dominate.
这类设备的基本原理是：电池正极产生的氢氧根离子与二氧化碳反应，将其转化为碳酸盐或碳酸氢盐，这些物质随后通过隔膜传递到负极；在负极处，较低的pH值使反应逆转，碳酸盐重新转化为二氧化碳气体。正极的作用是产生氢氧根离子，而负极的作用则是消耗这些离子。
The basic idea behind a device of this type is that hydroxide produced at the battery cathode reacts with CO2, converting it to carbonate or bicarbonate that passes through the separator membrane to the anode. There, the lower pH causes the reaction to reverse, with carbonate turning back into CO2 gas. The role of the cathode is to produce hydroxide ions; the role of the anode is to consume them.