GREEN SOLUTIONS FOR ENERGY CRISIS-METHANOL

Methanol economy

The methanol economy is a suggested future economy in which methanol replaces fossil fuels as a means of energy storage, fuel and raw material for synthetic hydrocarbons and their products. It offers an alternative to the proposed hydrogen economy or ethanol economy.

Since the 1990s Nobel prize winner George A. Olah started to advocate the methanol economy ^[1][2][3] and in 2006 he and two co-authors (G.K. Surya Prakash and Alain Goeppert) published a book around this theme ^[4]. In these publications, they summarize the state of our fossil fuel and alternative energy sources, their availability and limitations before suggesting a new approach in the so called methanol economy.

Methanol is a fuel for heat engines and fuel cells. Due to its high octane rating it can be used directly as a fuel in flex-fuel cars (including hybrid and plug-in hybridvehicles) using existing internal combustion engines (ICE). Methanol can also be used as a fuel in fuel cells, either directly in Direct Methanol Fuel Cells (DMFC) or indirectly after conversion into hydrogen by reforming.

Methanol is a liquid under normal conditions, allowing it to be stored, transported and dispensed easily, much like gasoline and diesel fuel is currently. It can also be readily transformed by dehydration into dimethyl ether, a diesel fuel substitute with a cetane number of 55.

Methanol is already used today on a large scale (about 37 million tonnes per year)^[5] as a raw material to produce numerous chemical products and materials. In addition, it can be readily converted in the methanol to olefin (MTO) process into ethylene and propylene, which can be used to produce synthetic hydrocarbons and their products, currently obtained from oil and natural gas.

Methanol can be efficiently produced from a wide variety of sources including still abundant fossil fuels (natural gas, coal, oil shale, tar sands, etc.), but also agricultural products and municipal waste, wood and varied biomass. More importantly, it can also be made from chemical recycling of carbon dioxide. Initially the major source will be the CO₂ rich flue gases of fossil fuel burning power plants or exhaust of cement and other factories. In the longer range however, considering diminishing fossil fuel resources and the effect of their utilization on earth's atmosphere, even the low concentration of atmospheric CO₂ itself could be captured and recycled via methanol, thus supplementing nature’s own photosynthetic cycle. Efficient new absorbents to capture atmospheric CO₂ are being developed, mimicking plant life’s ability. Chemical recycling of CO₂ to new fuels and materials could thus become feasible, making them renewable on the human timescale.

One m³ of methanol at ambient pressure and temperature contains 1.660 Nm³ of hydrogen (H₂) compared to liquid hydrogen; one m³ of liquid hydrogen (LH2) at -253°C contains 788 Nm³ of hydrogen (H₂)^[6])