Mature liquid nitrogen infrastructure
Liquid air is not yet produced commercially, but liquid nitrogen, which can be used in the same way, is already widely produced for industrial purposes, such as blast freezing, fre suppression and superconducting technologies. Liquid nitrogen is widely available not only in developed economies, but also rapidly industrialising countries such as China and India. For technical reasons there is often excess nitrogen production capacity. India, for example, has about 3,500 tonnes per day of spare nitrogen production capacity, which could be used to provide cooling for zero-emission cold chains.
Liquid air and liquid nitrogen are both produced by electric-powered plants, so either could provide a solution to the intermittency of renewable generators such as wind and solar: absorbing and storing 'wrong time' or surplus renewable energy to use on demand in grid or transport applications. Both liquid air and nitrogen can also be produced with the help of waste cold from LNG re-gasification (see the Appendix for more detail), which reduces the electricity required, and the carbon intensity, by about two thirds, and the cost by almost half. LNG imports are growing strongly in both China and India, and we estimate the cold from projected Indian LNG imports in 2022 could in principle help produce enough liquid air to fuel half a million liquid air TRUs. Similarly, by 2030 the projected global trade of 500 million tonnes of LNG would give off enough waste cold to help produce 184 million tonnes of liquid air, enough to supply cooling for 4.2 million refrigerated delivery trucks, double the current global fleet.67
Figure 4. How waste cold from LNG re-gasification could power the 'Cold Economy' in India. Source: E4tech