This story demonstrates society’s reliance on gasoline. Although there are constant warnings that gasoline will run out and that we must resort to other forms of energy, the recent events in New York suggest otherwise. Have we run out of options? The discovery of producing gasoline from air, at Air Fuel Synthesis (AFS), may give us another option.
In an experiment, AFS extracted oxygen, carbon and hydrogen, from carbon dioxide, and water, from the air, to form methanol which is then converted into gasoline. As consequence, this process produces half a litre of purified gasoline per day, using just air as a raw material. To explain further, carbon dioxide is extracted or “snagged” by passing air through a sodium hydroxide mist, causing sodium carbonate to form. Next, water is taken from this same air through a condenser. Then, in order to produce methanol (CH3OH), electrolysis is used to extract the required hydrogen, from the water, and the required carbon and oxygen, from the sodium carbonate, to create methanol. This methanol is then converted to gasoline through polymerisation (adding many molecules together).
The implications of this method are staggering because not only is the air around us readily available, but the process involves extracting carbon dioxide from the air. This means that any carbon dioxide produced by burning the gasoline would be extracted in making more gasoline. Therefore, using this gasoline would be carbon neutral, so long as the machinery involved in this process was powered by renewable energy sources such as solar or wind power.
However, before this method of gasoline synthesis from air is touted as the future of energy, the energy efficiency of this process must be considered. Substantive energy is required for this process and to ensure the process is carbon neutral, this energy must be generated by renewable energy sources, which have high capital costs. Therefore, this venture would only be heavily invested in, if the energy produced is used more frequently and if there is good profit return for investors, within the process i.e. energy efficiency.
In the final analysis, it is too early to know how to optimise the energy efficiency of this gasoline synthesis method. The energy efficiency currently is quite poor because the use of electrolysis within the process, as a cost effective and efficient way of splitting hydrogen from water, has not yet been found. AFS themselves say that further testing of efficiency is needed and that they need bigger factories for more research. Yet, AFS claimed the motorsport industry is taking an interest in their work because they are keen to reduce their own fossil fuel dependency. Despite the problems, this long term prospect of creating gasoline from air is an exciting one.
Contributed by Zia Farooq