Hydrogen Essay Research Paper ANALYSISThe Potential Markets

Hydrogen Essay, Research Paper

ANALYSIS

The Potential Markets For Non-Fossil Fuel Hydrogen

.Hydrogen, most of it produced from fossil fuels, is already widely used in the chemicals industry, notably in the

manufacture of fertilizers and petrochemicals. It would therefore be possible to substitute NFFH in this market.

However, the total that could be absorbed by 2040 is unlikely to represent more than about 3% of current total world

energy demand.

.NFFH could be used to satisfy much of the demand for heat. The existing UK natural gas distribution network could, for

instance tolerate the addition of up to 10% by volume of H2 . Higher concentrations would require a major investment

program, while the distribution of pure H2 hydrogen would require a totally new pipeline system.

.Perhaps one of the main future markets for NFFH is in the production of synthetic fuels from coal. This would reduce the

CO2 emissions normally associated with such processes, but would only become a viable option if limitations in the

supply of hydrocarbon fuels coincided with a requirement to reduce CO2 emissions.

.The use of H2 as a transport fuel is a possible option. It offers the potential for a marked reduction in both local and

global emissions and has already been used successfully in demonstration fleets powered by modified internal

combustion engines.

The main problems facing this technology are the comparatively large volume, weight and cost of on-vehicle storage and, for

passenger cars, the high infrastructure costs of a distribution system. For these reasons, buses and commercial vehicle fleets are

the most favorable applications. The future for this application will also be influenced by the development of fuel cells, which would

increase the efficiency of fuel utilization. However, the first practical application of fuel cells might involve alcohol fuels or natural

gas.

Hydrogen Production Methods

H2 can most economically be produced from natural gas, although refineries commonly obtain their process hydrogen in-house,

from the partial oxidation of fuel oil. H2 can also be produced by gasifying coal. Such production techniques do, however, give rise

to CO2 emissions and the future development of H2 technologies is more likely to depend on production from non-fossil fuel

sources. Two such sources are under development: biomass and water.

Although the technology is only at the demonstration stage, H2 can be produced by the gasification of biomass. This procedure,

however, only comes into the non-fossil fuel category if the biomass production does not itself involve the consumption of fossil

fuels.

The other important route for the production of H2 involves the electrolysis of water. This technique is already being applied in

locations close to sources of cheap electricity. Plant energy efficiencies of 70-75% are currently being achieved in practice, and

efforts are being made to enhance process efficiency by improving cell designs and increasing cell temperatures. Efficiencies of

93-98% have been demonstrated in the laboratory, but these have yet to be tested in a full-scale application. Solid polymer and

solid oxide electrolyte systems are also being investigated as possible methods of improving efficiency. Some indication of the

relationship between efficiency, electricity prices and H2 production costs is given in Table 1 .

In order to try to circumvent the inefficiencies of electrical power generation as well as electrolysis inefficiencies, much research

has been devoted to the thermochemical production of H2. Although the principles have been successfully demonstrated in pilot

plants, efficiencies are lower than those achieved in the best electrolysis plants and capital costs are likely to be higher.

Furthermore, the most promising of the thermochemical techniques involve the use of high-grade heat, and some difficulty exists

over finding an economic non-fossil fuel source of such heat.

Hydrogen Distribution and Storage

The most appropriate methods of H2 distribution and storage depend on the form in which it is required, and the size and location

of the market.

Pipelines normally offer the cheapest method of long-distance, overland transport, although usually only for H2 in its gaseous

form. It is cheaper to transport liquid H2 in road or rail tankers. Satisfactory transport by sea requires either liquefaction or the

preparation of a hydrogen-rich chemical ‘carrier’ such as ammonia.

Where H2 is derived using electrical power, direct transmission of the electricity to a market-located production site must he

considered as a possible alternative. This is unlikely to be the most economic option for distances exceeding 1,350 km, although

other factors may also need to be taken into consideration, including the terrain to be crossed and H2 demand characteristics.

Storage costs depend on the quantity of H2 to be stored, its physical form and the duration of the storage. Depleted gas wells are

the most economical method

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