Although hydrogen is widespread and abundant on Earth, its extraction from water or hydrocarbons requires much energy. Today, most efforts for efficient and economical hydrogen production are concentrated on natural gas and coal, because they are still the most inexpensive sources of hydrogen. One of the goals of the envisioned hydrogen economy is the mitigation of greenhouse gas emissions, but this would imply capture and sequestration of CO2 on a very large scale. Alternatively, H2 would be obtained by the electrolysis of water, but the required energy must be derived from non-fossil fuel sources (atomic and any form of alternative energy source). Even if this might become technologically and economically possible, the consequences of storing huge amounts of CO2 un derground or at the bottom of the seas are, at best, uncertain. In the long term, however, considering the finite amounts of fossil fuels, hydrogen will have to be produced increasingly using not only renewable energy sources such as wind and solar, but also nuclear energy. Once generated, the physical and chemical properties of hydrogen makes its storage, transportation and safe handling difficult and potentially hazardous. Whether the production is centralized or decentralized, due to its unique properties, a totally new and expensive infrastructure would have to be built to supply consumers with hydrogen. For vehicles, onboard hydrogen storage is likely to remain voluminous and costly, while the use of hydrogen as an automotive fuel from an energy efficiency and emissions viewpoint would be feasible only if used in combination with fuel cells. Efficient, reliable, and affordable fuel cells will almost certainly become a reality in the not too distant future, although unless an efficient and safe metal hydride or other storage system is developed it is also questionable to what degree people would feel safe, knowing that they are driving cars with a high-pressure tank filled with an explosive and highly flammable gas under their seats.
Other static applications of hydrogen fuel are feasible in suitable cases, and will be developed in time. The storage and transportation of energy in the form of hydrogen, as discussed here, has serious drawbacks and problems. Instead of the volatile and potentially explosive hydrogen gas, a new and feasible alternative in energy storage by its conversion with atmospheric CO2 to liquid methanol is therefore proposed. In the near future, still-existing large natural gas reserves can be converted directly to methanol (without first conversion to syn-gas), thereby solving problems of transportation and shipping associated with LNG and allowing the gradual introduction of methanol-powered cars. What we now term the "Methanol Economy" (see Chapters 10 and 14) will eventually involve the recycling of CO2 to methanol rather than its sequestration. This will provide an inexhaustible fuel source as well as a carbon source for synthetic hydrocarbons and their products while mitigating global warming caused by the generation of excess CO2 from burning fossil fuels. In order to achieve its goals, the methanol economy will also require the production of hydrogen on a massive scale through water electrolysis, using electricity generated from any non-fossil sources (renewable energy, and also atomic energy). In this way, energy will be stored not as volatile hydrogen gas, but by its conversion with CO2 into convenient and easy-to-handle liquid methanol.
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Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.