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THE HYDROGEN CYCLE - DOC

VIEWS: 155 PAGES: 2

									Climate Action Tomaree                    (CAT)
                   A working Group of EcoNetwork, Port Stephens.


THE HYDROGEN CYCLE.
Global warming is caused by the build-up of Greenhouse gasses in the atmosphere.
These gasses are the inevitable result of our use of carbon based materials [coal,
petroleum, natural gas] to generate the energy which drives our society. These
materials generate heat by combining with oxygen in an exothermal reaction [ie: gives
off heat – which we want !], the by-product of the reaction being carbon dioxide [the
most important greenhouse gas - which we emphatically do not want !]. There is no
practical way around this – if you want to get energy from carbon [ie: coal, petroleum,
natural gas], you have to burn it [ie: combine it with oxygen in the atmosphere] and the
inevitable result is carbon dioxide.
The purpose of this paper is to demonstrate that an alternative energy generation cycle
is possible, based on hydrogen combining with oxygen in the atmosphere, again in an
exothermal reaction [ie: giving off heat] but with the only by-product being water.
The hydrogen cycle is generally the basis of fuel cell technology, in which hydrogen and
oxygen [air] are combined to produce an electrical output. This technology is not new, it
has been used on all the NASA space missions. It is particularly important to note that,
although we have alternative ‘clean’ technology available for electrical power generation
[solar cells, wind, biogas etc.], the hydrogen cycle/ fuel cell technology is a possible
technology for powering cars and trucks [demonstration vehicles are on the road in the
USA and Europe now] when petroleum becomes too scarce or too expensive for that
application [some time in the next 25 years ?]. The hydrogen cycle is also one of a
limited number of sustainable methods for generating base load electricity. It naturally
follows that introducing this technology requires significant government involvement – it
is not something which individuals can do. The big question for our government is –
“what are you doing about the big tasks required to move to a clean, sustainable
technology, where we can keep our society running at a reasonable level of comfort and
progress, without destroying our children’s society ?’
References :
This paper is based principally on the following references –
                U.S. Department of Energy, Energy Efficiency and Renewable Energy
                 Program - Hydrogen, Fuel Cells & Infrastructure Technologies -
                 <www1.eere.energy.gov/hydrogenandfuelcells/>
                Schatz Energy Research Centre – <www.schartzlab.org/>
                ‘The Hype about Hydrogen’, Joseph J Romm, Five Island Press,
                 Washington, 2005.
                ‘Greenhouse Solutions’, Mark Diesendorf, UNSW Press, 2007.
THE SOLAR HYDROGEN CYCLE.
The diagram below illustrates the Solar Hydrogen Cycle on the basis of the hydrogen
being generated from water using electric power from photovoltaic solar panels. It does
not have to be generated that way and most of the [quite considerable quantity] of
hydrogen used today in the chemical industry is manufactured chemically. However,
this is the only sustainable method and it is possible that a significant industry could be
established in the desert regions of Australia, generating hydrogen by the method
shown in the diagram and shipping it to points of use [in Australia and overseas] in a
manner similar to the way we now ship natural gas.

VERN. 4                               P 1 of 2                         1 May 2010
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Climate Action Tomaree                    (CAT)
                   A working Group of EcoNetwork, Port Stephens.
Process Description

                                                                        In this typical
                                                                        schematic
                                                                        process,
                                                                        electricity from
                                                                        photovoltaic
                                                                        panels is used
                                                                        to power an
                                                                        electrolyzer, a
                                                                        device which
                                                                        splits water
                                                                        (H20) into its
                                                                        elemental
                                                                        parts, hydrogen
                                                                        (H2) and
                                                                        oxygen (O2).



The oxygen is released into the air and the hydrogen is pumped into storage tanks,
where it can be kept on site or transported to regions that need energy.
At night or in bad weather, when solar energy is not available, the hydrogen is
recombined with oxygen from the air in a fuel cell, which directly converts the chemical
energy in hydrogen into electricity. The only byproduct of this process is pure water.
Electricity from fuel cells can be used in the same ways as power from a utility company
or other type of generator, to run appliances and light bulbs, electric motors, and to
power cars. Solar hydrogen allows us to use the power from the sun twenty-four hours a
day, and provides us with an abundant, clean, efficient, locally produced, sustainable
source of energy.
AVAILABILITY.
Hydrogen is the most common element in the universe – it is eminently sustainable
since at the end of the process the hydrogen ends up where it began, as water. It is not
like carbon fuels where the carbon, at the end ot the cycle is locked away in carbon
dioxide, or some even nastier forms such as carbonic acid.
BUT.
The favoured approach by current policy makers is to make hydrogen in the cheapest
way, by distillation from coal. This manufacturing process produces large quantities of
CO2 which negates the environmental advantage of the carbon cycle. Only hydrogen
produced cleanly and sustainably should be considered.
This whole process is still in the experimental stage – we do not have enough
experience with this technology to implement it on a large scale immediately. In
particular, widespread use of hydrogen powered vehicles will require building a network
of hydrogen filling stations. All this simply highlights the necessity of motivating our
politicians to adopt a more focused and commited attitude to the whole problem of
building a sustainable society to replace the temporary, exploitive society which we now
have and which is approaching its inevitable end. A big ask !!

John M Kelly, BE, BA.       3 December 2007.

VERN. 4                               P 2 of 2                       1 May 2010
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