A national or global energy supply which is based on methanol. Sources and forms of use are displayed in the following scheme:
Methanol is an alcohol with the following chemical formula:
H | H - C - O - H | H
Compared to hydrogen methanole is much easier to store and to handle. Methanol is liquid at typical temperatures and can therefore be stored in standard tanks made of metal or plastics. The methanol suppy infrastructure is nearly the same used for gasoline or diesel. Additionally methanol can be used as substitute for conventional fuels after a slight modification of internal combustion engines.
The energy density of methanol is about half that of gasoline or diesel and more then two times higher than that of liquefied hydrogen. A further advantage of methanol: It can be used in direct methanol fuel cells (DMFC) to convert its chemical energy into electric power directly. This solves the problem to store hydrogen for classic fuel cells.
Finally there is one problem to solve: How to produce methanol with a minimized environmental impact?
During combustion -- or the chemical reactions in a DMFC -- carbon dioxide is released. A production method which uses carbon dioxide from the atmosphere and water together to produce the methanol fuel will close a technical carbon cycle. Such a carbon cycle could coexist beneath the biological carbon cycle and the net carbon emissions are zero.
Methanol made from biomass will lead to a zero carbon fuel, but requires large areas of arable land to produce the primary biomass. The conversion from biomass to methanol has a moderate efficiency leading to higher input of biomass and hence for a larger need for arable land. Arable land for biomass/fuel is direct competitor for the production of vegetables, fruits and corn, the "fuel" for our bodies and limited.
Other methods address the industrial production of methanol by bacteriae or other micro organisms which convert light, water, carbon dioxide and some other compounds into methanol. Some research is done to find micro organisms which do the conversion with a sufficient efficiency. The advantage of this method is the independency of the availablity of arable land -- microorganisms can do their job in glas tubes in deserts. The limited efficiency diminshes the chance of a system which is "powered" by microorganisms.
Future research should investigate possiblities to use catalysts -- or biocatalysts -- on membranes which provide the area to convert light into methanol. This is a "far future" project but it might combine the requirements of a cheap and efficient mass technology with catalysts or biocatalysts derived from micro organisms.
Methanol is one of the most promising candidates of a sustainable fuel if a production process is established which can be operated at zero carbon emissions without the hassles of liquefied gases and a totally new infrastructure.