Whatever happened to the water-fueled engine?

the reason why i reply to steve 41oo is because he or she sounded just like the church during the middle ages saying the world is flat and speaking all high and mighty about the "truth" of god, or the other thousands of people that said the horseless carrage will never catch on.

Despite its abundance in the universe, hydrogen does not occur freely on earth, as it reacts very readily with other elements. For this reason, the vast majority of hydrogen is bound into molecular com-pounds. To obtain hydrogen means to remove it from these other molecules. With respect to the energy required, it is easy to remove hydrogen from compounds that are at a higher en-ergy state, such as fossil fuels. This process releases energy, reducing the amount of process energy required. It takes more energy to extract hydrogen from compounds that are at a lower energy state, such as water, as energy has to be added to the process.

The process of extracting hydrogen from water is called electrolysis. In principal, electrolysis can be entirely non-polluting and renewable, but it requires the input of large amounts of electrical energy. Consequently, the total envi-ronmental impact of acquiring hydrogen through electrolysis is largely dependent on the impacts of the source power.

In electrolysis, electricity is used to decompose water into its elemental components: hydrogen and oxygen. Electrolysis is often touted as the preferred method of hydrogen production as it is the only process that need not rely on fossil fuels. It also has high product purity, and is feasible on small and large scales. Electrolysis can operate over a wide range of electrical energy capacities, for example, taking advantages of more abundant electricity at night.

At the heart of electrolysis is an electrolyzer. An electrolyzer is a series of cells each with a positive and negative elec-trode. The electrodes are immersed in water that has been made electrically conductive, achieved by adding hydrogen or hydroxyl ions, usually in the form of alkaline potassium hydroxide (KOH).

The overall reaction that occurs is very simple:



2H2O + Energy -> 2H2 + O2



The rate of hydrogen generation is related to the current density (the amount of current divided by the electrode area measured in amps per area). In general, the higher the cur-rent density, the higher the source voltage required, and the higher the power cost per unit of hydrogen. However, higher voltages decrease the overall size of the electrolyzer and therefore result in a lower capital cost. State-of-the-art elec-trolyzers are reliable, have energy efficiencies of 65 to 80% and operate at current densities of about 186 A/ft2 (2000 A/m2).

A fuel cell reverses the process of electrolysis. Electrolysis adds electrical energy to low-energy water to release two high-energy gases. A fuel cell allows the gases to react and combine to form water, releasing electrical power. Both proc-esses release heat, which represents an energy loss.

When viewed together with fuel cells, hydrogen produced through electrolysis can be seen as a way of storing electrical energy as a gas until it is needed. Hydrogen produced by electrolysis is therefore the energy carrier, not the energy source. The energy source derives from an external power generating plant. In this sense, the process of electrolysis is not very different from charging a battery, which also stores electrical energy. Viewed as an electricity storage medium, hydrogen is competitive with batteries in terms of weight and cost.



To obtain 1 m3 of hydrogen from electrolisys we need about 5 kWh of electrical energy.



To be truly clean, the electrical power stored during electrolysis must derive from non-polluting, renewable sources. If the power is derived from natural gas or coal, the pollution has not been eliminated, only pushed upstream. In addition, every energy transformation has an associate energy loss. Consequently, fossil fuels may be used with greater effi-ciency by means other than by driving the electrolysis of hydrogen. Furthermore, the cost of burning fossil fuels to generate electricity for electrolysis is three to five times that of reforming the hydrogen directly from the fossil fuel