EARTH WARMING – FOSSIL FUELS – SEWAGE ENERGY
Introduction:
There scarcely that a day goes by that the problem of earth warming has been brought to our
attention. Earth warming is caused mainly by the combustion of carbon. All fossil fuels contain
carbon. The fossil fuels include gas, coal, timber, fuel oil, diesel, and spirit fuel such as petrol. All
fuels containing carbon produce oxides of carbon in the combustion process, (CO and CO2) and the
gases formed can contain up to 16 times their weight of the original fuel. For the past few years the
use of fossil fuels has accelerated to the point that the world is dependent upon it. Most of the
world’s supply of electric power is generated by fossil fuels, mainly coal, and heavy fuel oil. Nearly
all of the world’s power supply depends almost 100% on the use of fossil fuels. The large ocean
going liners, the aeroplane, the motor car, a good proportion of home heating, home cooking and
the production of hot water depend very heavily on the use of fossil fuels. It is little wonder that
the fossil fuels are the main culprit of earth warming as they are by far almost the main source of CO
and CO2. As a matter of fact the only source of available energy to man containing no carbon is
electricity and the electricity is generated by fossil fuels and clean energy is almost eliminated.
However, electricity can be generated by hydro power extracted from the world’s waterway by solar
power and by wind power. Because of the wide use of fossil fuels, over the past 100 years over 90%
of the world’s energy is carried out by the combustion of fossil fuels.
In fact the only way to eliminate the use of fossil fuels is to generate electricity by means of nonpowdered fuel which is almost an impossibility. The motor car for instance, is being employed in
greater numbers every day. The use of the motor car should not be excluded by modern society and
the growth of the use of the motor car has become enormous and the conversion of motor car
drives from the internal combustion engine to electric drive would be no small feat. However, it is
not impossible that this could be achieved.
The greatest source of energy in the world is one we have seldom touched and that is the energy
form the tide of the world’s oceans. In fact, the energy available from this source is many times
greater than the total energy used by the world today and this would be the main source to be
harnessed with the world to utilise almost 100% clean energy and to eliminate carbon oxide from
the atmosphere. All land is surrounded by water and these oceans are never still. Countless
thousands of tonnes of water are on the move around the world’s oceans and the tidal effect of this
movement of the ocean may be harnessed to produce all the electrical energy the world will require
to replace the energy at present supplied by combusting fossil fuels.
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The replacement of fossil fuels by the use of solar energy and wind power has many disadvantages.
For instance, the solar power and wind power are not always available when required and cannot be
relied upon to be a constant source of energy for the demand of the requirements of energy in
today’s world. The power from the ocean’s current, on the other hand, will be available at all times.
In fact standard models for ocean power generation can be made available by the construction of a
module which could be ‘spudded’ into coastal water to provide ample power for the whole world.
This could be the method for total electric power for replacement of fossil fuels.
Sewage Energy:
A source of energy available at all times is the energy available from solid sewage. Solid sewage has
a 20% greater energy than good quality coal and has been tested at 25 MJ’s per kg specific energy
which is equal to 12,000 BTU’s per lb calorific value. Sewage energy has been proven to be
combusted in pulverised form similar to that of pulverised coal. In fact it can replace pulverised coal
in the boilers at present used for the production of electric power, no alteration is needed.
Solid sewage may be dried and pulverised a lot easier than coal. It is simple to handle and utilises
the same dryers and combustion chambers as pulverised coal. To prove this point a small model
was constructed to operate for the production of solid sewage in the form of pulverised coal. The
size of this Model had the capacity to service 15,000 capita per day. Solid sewage which has been
discharged into settling tanks via sewage transfer into a digester is collected from the settling tank
and by sludge pump discharged to a centrifugal dewatering process where it is pressed to 20% solids
content. In this condition, it was heated to a pulverised dryer in contact with heated air at 800oF
which would ensure the product was sterilised and deodorised. From the pulveriser, it was
converted to powder form having the consistency of 76 microns which would fire direct into a
pulverised fuel burner to fire a boiler.
How to Tackle the Problem of Earth Warming:
Earth warming has been approaching for many years. However, we are not fully equipped to deal
with the problem. It has now become obvious that fossil fuels must be regulated so that their use
may be gradually reduced so that other methods can be put into practice. The world’s population
must be brought to the realization that earth warming is not a myth. It is happening right now and
must be tackled right now. However, it is a major operation to reduce the use of fossil fuels and
replace their use with heavily reduced carbon energy. It can only be done electrically.
The only source of constant renewable energy on the scale that would suit the world’s capacity is
the energy available from the oceans. We know it can be done and is the only long term solution.
Solar energy and wind energy may go a long way to solving the problem but it would not provide the
necessary complete solution. The use of fossil fuels is escalating daily so that the problem of earth
warming is increasing at a higher rate. It is now estimated that in some thirty years, earth warming
will have increased to a dangerous level and that it is imperative for its complete control can no
longer be delayed. Moreover, the problem must be tackled on a global scale if it is to succeed at all.
A complete changeover to electrical power to replace fossil fuels is by no means impossible and that
in the long run such a change will benefit the earth both cost wise and environmentally wise. For
many years now we have been conscious of the great advantages of hydro-electricity and it has
become an absolute necessity to realise that the necessity to generate electricity by the use of ocean
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power must be tackled immediately if such a complete changeover is to be carried out. In the forty
years we have available to us before the use of carbon fuels must be heavily reduced or eliminated.
Planning on a global scale must be initiated. Methods to carry out this changeover must be
determined with the adoption of a scheme to enable the work to be carried out to meet practical
and financial requirements. Some countries are already tackling the problem by reducing the use of
coal and closure of coal mines. We are now left with huge investments for power generation by
fossil fuels becoming a waste. This however, is not an absolute necessity.
There is one fossil fuel that cannot be eliminated and that is the carbon gases which results in
sewage. The problem of carbon gases from sewage is increasing globally with the world’s
population increasing. It has now been established that each person contributes an average of 70
grams of BOD on a daily basis. From this figure it has been established that 1 kg of sewage BOD has
a specific energy of 25 MJ’s and that 1 lb will have a calorific value of 12,000 BTU’s which these
figures show that each person contributes 0.54 KW’s of potential energy per day. Therefore, 1,000
people can produce 540 KW’s per day.
The importance of the effect of sewage on the environment is seldom taken into account and it is a
fact that the effect of sewage on earth warming is one of the world’s greatest problems of our time.
It is more of a problem because it occurs on a daily basis and cannot be eliminated. Other fossil
fuels such as coal and oil can be left in the ground if their use is not required. Whereas sewage
cannot be disregarded because it is a natural occurrence and we are left with no other choice to
accept its detrimental effect on our environment. Even if you bury sewage its gases will eventually
come to the surface and into the atmosphere. There has been plenty of evidence that not only does
this occur but the time involved is a lot less than what we think. There is no way to dispose of solid
sewage in a manner that will not affect the environment. If it is to be used as a fuel and its
combustion controlled to ensure that all carbon is converted to CO2 and fully oxidised. In this way
the least harm will be done to the atmosphere but it cannot be avoided completely. Even if sewage
is converted to a fertiliser, its effect on the environment will be little if any different than that if it
was freely discharged.
When one considers that 1,000 people produces up to 540 KWs of sewage energy per day and every
day and one million people produces 540 MW’s per day one quickly realises the problem with
sewage. Having the problem of sewage to face will make the realisation that the use of other fossil
fuels which can be reduced, must be tackled on a global basis. The increase in population will
eventually cause a major problem with earth warming unless some other form of control can be
introduced. The control of sewage pollution is an immense problem which must be tackled
immediately. As yet man has provided no easy solution of which to tackle the problem of sewage
treatment to reduce its detrimental effect on the world’s environment.
Patrick Potter
(This paper is copyright and cannot be reproduced, copied or altered in any way or form without the prior
written permission from the author Patrick Potter, 25 Queenwood Avenue, Hamilton, New Zealand – Phone
07 8556224 – email: patpot@xtra.co.nz)
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