The original source of this article was originally published in the Nature journal.
We desperately strive for better energy management. Wind-turbines, run-of-the-river electricity, and solar panels are only a half of the equation. Where the energy goes is the other half. And while installing those power-saving LEDs is certainly worth something, it should be considered that households consume only 21% (in US, 26.8% in EU) of all the electricity. Vast majority of energy is actually consumed by industries. Especially in material-processing industry, implementing theoretical (but achievable) technologies, would bring significant changes. David S. Sholl and Ryan P. Lively, professors at Georgia Institute of Technology propose seven chemical separation processes, which would dramatically lower the amount of energy used in industry.
1. Hydrocarbons from crude oil
Two liters of crude oil are processed each day for every person on this planet. Almost all the refineries use atmospheric distillation, which on a global scale consumes the same amount of energy as all of the United Kingdom did in 2014. Membrane-based separation uses different properties of carbohydrates to separate them from each other, and it is much more energy efficient than heat-driven distillation.
2. Uranium from seawater
Contrary to popular belief, uranium, like many other materials, is not only in underground deposits, but also in seawater. It is present at part-per-billion level, but given the amount of seawater Earth has, there is about 4 billion tonnes of it hiding there. Technology to capture metals, including uranium, from seawater is already available, but not used at a larger scale.
3. Alkenes from alkanes
Similarly to gasoline production, distillation is used to divide alkenes from alkanes in order to create plastics. So far, it is being done using cryogenic distillation, at temperatures around −160 °C. This process alone uses about 0.3% global energy. Clever usage of membranes could help here again, however technology to produce as pure materials at room temperature and slightly elevated pressure is not available. Still, hybrid process combining these two methods could account for 2 or 3 times lower energy consumption of the process.
4. Greenhouse gases from dilute emissions
It is both very difficult and very expensive to capture greenhouse gases from emissions with our existing methods. There is a strong need for a process that would be economically viable for power plants if we wish to lower the global carbon emission production.
5. Rare-earth metals from ores
Besides other valuable applications, rare metals are involved in many ecology-related innovations. Unlike their name suggests, they are present plentifully in ore. The actual problem is their separation from other metals. Various energy-costly processes are used to capture pure rare metals, hence a better collection method would bring bigger application of their much needed benefits.
6. Benzene derivatives from each other
Benzene derivatives are much wanted commodities in most of the manufacturing industry. Their production relies on an older technique, which is quite inefficient, costing us 50 GW of energy annually (the amount which would power roughly 40 million households).
7. Trace contaminants from water
Turning salty water to pure water, but not via desalination, which is very costly and inefficient. Reverse-osmosis filtration on the other hand, is a process that applies pressure to a membrane in order to make the water contaminant clean. This process is already being used in Middle East and Australia. It still struggles in highly contaminated areas, but further research could lead to its wide-spread use.