Mike Koefman

CLIMATE CRISIS - HYDROGEN SOLUTION

"Our five most pressing environmental problems." (Sir Crispin Tickell, Green College, Oxford: Channel 4, December 1999).

"Climate perturbation

Threats to water quality and availability

Soil loss

Loss of biodiversity

Human population growth."

The most pressing of these is climate change. Caused by our overloading of the atmosphere with carbon dioxide, it is also part-cause of other problems; however, it is also amenable to analysis - examination, explanation and, as argued here, remediation. Science and common sense con-cur: such remediation can only be achieved through the phasing out of all fossil fuels (the overwhelmingly most important source of carbon dioxide), and by their re-placement by a non-carbon fuel.

FOSSIL FUELS

MERITS: Two only.

They are reasonably compact (e.g. 100 tonnes of kerosene, 140 cubic metres, will propel a 300 tonne aircraft from London to Delhi); and such fuels are fairly "easy" to mine.

DRAWBACKS:

Their main combustion product (apart from the relatively harmless water) is carbon dioxide. Six billion tonnes of fossil fuels (expressed as oil-equivalent) are burned by humankind each year. The resulting carbon dioxide, some twenty billion tonnes, now outstrips the capacity of nature's normal sequestration mechanisms. As a result, about one third (John Houghton, Global Warming, The Complete Briefing ) of this excess carbon dioxide is taking part in a long-term build-up in the atmosphere. The cumulative effect so far has been to increase the atmosphere's previously steady-state carbon dioxide load from 280 parts per million (by volume) in 1850 to 360 ppm in the year 2000; thus instituting the anthropogenic Greenhouse Effect.

The present rate of increase in this excess load of carbon dioxide in the atmosphere is at least 1.7 ppm per year. The World Energy Council foresees concentrations of 500 ppm by the year 2050 under its "Business as Usual" scenario. And even to "achieve" such a dangerously high stabilisation level as 1000 ppm, a strong reduction in present-day annual emissions will be necessary. (John Houghton, IPCC, 1998)

This is a unique and unprecedented alteration to one of the physical and chemical parameters (temperatures, pH values, salinities, insolation etc.) which have governed life on Earth since before the arrival of man. The conscious and unremitting injection of such destabilising quantities of carbon dioxide into our shared atmosphere must rank almost as an act of vandalism, perpetrated by humanity upon itself and upon the whole environment.

This excess carbon dioxide has a radiative forcing effect upon the Earth's heat budget, by returning to the surface a small but decisive amount of infra-red heat which would otherwise have escaped to space. This Greenhouse Effect is expected to raise average global temperatures by between 1.5 and 4.5 degrees Centigrade by the year 2100. Unless this process is checked, the results are expected to include:

A greatly altered world climate, with regions which are already stressed and fragile (e.g. the Sahel, rain forests, corals) risking permanent degradation, and consequently:

Rainfall and fresh water flows being gravely affected, increasing the possibility of war between competing communities;

A great increase in the frequency of storms, hurricanes and other violent air/water events;

A grave disruption of agriculture and fisheries;

The spread of vector-borne diseases of plants, animals and humans;

Strong localised cooling in some hitherto temperate lands; for example, the curbing or arrest of the northern stretch of the Gulf Stream, engendering a climate like that of Labrador or Eastern Canada in the UK and Ireland (Rahmsdorf, Nature 388, 1997),

Very large human transmigrations, perhaps meeting bitter opposition, and perhaps including whole populations of NW Europe for example seeking sanctuary further south.

THE HYDROGEN ALTERNATIVE

Frequently Asked Questions:

WHICH hydrogen ?

The hydrogen which lies safely in the World's waters.

HOW MUCH water would be needed ?

One tonne of water holds about 110 kg of hydrogen, whose energy of combustion equals that of about 330 kg. of petroleum. Hence, if mankind's future fuel needs could be met by 10 billion tonnes of oil per annum, they could also be met by the hydrogen extracted from 30 billion tonnes of water, which has a volume of 30 cubic km. In order to give each person on the planet access to the average energy "ration" of present-day Europe, this figure can be raised to 100 cubic km per annum - a vanishingly small fraction of the World's oceans, and which will be recycled back into the ocean.

HOW do we gain access to this locked-up hydrogen without expending more energy than would be yielded by the hydrogen's combustion ?

In the proposed hydrogen-powered world the hydrogen acts as an energy carrier and fuel. So the amount of energy used to make the hydrogen is equal to the amount of energy we want to transfer plus whatever proportion of energy is lost due to inefficiencies in the process. We use the energy that we want to transfer to make the hydrogen and recover most of that energy when we use the hydrogen as a fuel. The energy to make the hydrogen will come from clean renewable sources harvesting natural energy flows, all solar in origin. The most important ones in the UK are:

Wind power (offshore and onshore)

Gasification of renewable biomass

Classic photo-voltaics

Hybrid Solar Voltaic / High Temperature Hydrogen Production System (Padin, Veziroglu, Shahin, Int. Journal Hydrogen, April 2000)

IS IT REALLY SO SIMPLE ?

Research, development and refinement are technologically and financially very demanding, but the underlying principle is indeed simple: all the Sun's heat which we receive on Earth is ultimately reradiated, as infra-red, out into space from the Earth's emissive surface and from it's atmosphere. The technology of hydrogen energy merely inveigles a small part of this energy into taking a circuitous path, to our human advantage, before resuming its inevitable spacebound destination.

ISN'T HYDROGEN DANGEROUS ?

Like all fuels, hydrogen can be dangerous. Each fuel has its own set of dangers. Hydrogen, for example, demands much lower ignition energy than other fuels ("bad"), but rapidly disperses upwards in an outdoor spill ("good"). Chemical engineers have handled hydrogen for decades, and do not find it a troublesome gas.
Hydrogen is no more dangerous than petrol.

HYDROGEN IN A NUTSHELL ?

Hydrogen, abstracted from water or bio-mass, using renewable energy resources, can function as an energy store and as an energy vector; it can answer all the fuel needs of industry, heating and cooking; it can satisfactorily power transport by land, air and sea; it can be used for the generation of electricity, and is the ideal fuel for fuelcells, a vital technology for the future. However, hydrogen also poses challenges for the engineers who will bring it into widespread use.

Well-funded research will be needed to meet the storage difficulties posed, for example, by hydrogen's low density.

Another well documented problem that requires careful technical consideration is the avoidance of embrittlement of metals by hydrogen.

IMPLEMENTATION of the HYDROGEN ECONOMY in the UK:

AN OUTLINE

RESEARCH:

Continuous, from public funds, with the transfer of money from fossil fuel subsidies and fusion research, and from a carbon tax.

ENERGY EFFICIENCY:

This should be at the core of the system, since hydrogen will always have to be "won" from water or bio-mass. It should be noted that energy efficiency measures on their own cannot transform our present carbon economy. For example, the cost merely of super-insulating all UK housing - 25 million dwellings @ £40,000 each - would approach £1 trillion. It is clear that chemistry and cost together rule out the carbon-reduction route to climate remediation.

LAUNCH: In the first phase of a hydrogen introduction programme, the initial scarcity of solar hydrogen would necessitate the sourcing of hydrogen from the very large quantities of tradeable, sulphur-free methane (natural gas) which are available from UK gas fields and from the world market. The classic "shift reaction" which is still used to produce hydrogen from natural gas for industrial purposes would be discarded, as it inevitably results in the escape of large quantities of carbon dioxide, the very gas which we are trying to suppress.

Instead, more recent pyrolytic procedures would be employed, by which the same quantity of hydrogen is obtained, but without the unwanted by-product carbon dioxide. The only "waste" is raw carbon-black, a non-toxic solid which does not pose insuperable disposal problems. In this way, although the combustion potential of the carbon component of the methane is sacrificed, we have managed to obtain large quantities of clean hydrogen gas, whilst waiting for the long-term solution of wind power and solar hydrogen to come on stream.

At the same time, the challenge of adapting all our energy-dependent activities to hydrogen fuel (heating, cooking, transport etc.) could be met by dedicated research and development.

CONTINUATION:

The off-shore wind resources of the UK and Ireland (hundreds of GW available), and native solar and bio-mass potential, and the displacement of the present international carbon trade by a solar- hydrogen trade, are among the elements of a feasible future powered by hydrogen. The political risks would be great, but the ultimate political gains would be greater.

Mike Koefman,

Manchester, August 2000.

Web site Manager Jill Norris

hydrogen@hydrogen.co.uk