Hamburg, Germany
16°C
Clear
Humidity: 79%
Wind: NE at 9 mph
By Engr. Anopuo Okey B.Engr. MSc
The issue of global warming and general climatic change 
should be a matter of concern to any average thinking mind. The frequent nature catastrophe on the ageing earth these days, typically suggests an imbalance or a shift on the forces sustaining the mother earth.
I can combine our urge for comfortability with means as we live here on earth, we also have the responsibility to leave the earth better than we found it and not to live at the expense of the generation to come.
Generally, the greenhouse effect is the process by which an atmosphere warms a planet. This effect was first mentioned by Joseph Fourier, a French mathematician and physicist in the year 1824 and subsequently quantified by a Swedish physical chemist Svante Arrhenius in 1896. In other wards, greenhouse effect is basically the rise in temperature that the earth experiences as a result of the trapping of the energy from the sun by certain gases in the atmosphere. These gases include (Carbon dioxide, water vapour, methane, nitrous oxides etc).
A couple of the planetary bodies such as Venus, Mars and etc with atmospheres such as titan experiences also greenhouse effect. Just above the atmosphere, the solar power flux density averages about 1366 watts per square meter approximately 1.740x1017 W over the entire earth.
The Solar power hitting the earth is balanced over time by a roughly equal amount of power radiating from the earth. 30% of the solar radiations reaching the earth are being reflected while 70% of these radiations are being absorbed. This absorbed energy heats the atmosphere, lands, oceans and powers life on the planet.
One of the most recent quantification of carbon dioxide amount in the atmosphere from Mauna Loa observatory show that CO2 has increased from about 313 ppm (parts per million) in 1960 to about 375 ppm in 2005. The current observed amount of CO2 exceeds the geological record of CO2 maxima (~300 ppm) from ice core data [1].
This suggests that the CO2 production rate from increased industrial activity (automobile use and fossil fuel generation) and other human activities such as land-use changes has overwhelmed the normal feedback control mechanisms. Global climate model calculations indicate that the elevated CO2 levels are likely to lead to global warming. There has been an observed global average temperature increase of about 0.5˚C since 1960 [2]. There is still some public controversy about the role of human activities and that of CO2 and other greenhouse gas increases on global warming.
The indifference shown by key members of the industrialized countries towards this all important global concern puts question towards the seriousness of the motives behind the over emphasized political issues like war on terror, HIV/AIDS, poverty eradication in continental Africa and the likes. For instance the position of the USA on Kyoto protocol could be viewed as that of lack of commitment to global climatic balance. The United States of America (USA), although a signatory to the protocol, has neither ratified nor withdrawn from the protocol. As the signature alone is mostly symbolic, the protocol is non-binding over the United States unless ratified. Australia refuses to sign the protocol arguing that it is going to cause job loss in the country. Canada however on December 17, 2002, ratified the treaty. It is observed in Canada that while numerous polls have shown support for the Kyoto protocol, there is still some opposition, particularly by some business groups, non-governmental climate scientists and energy concerns, using arguments similar to those being used in the United States of America.
There is also a fear that since US companies will not be affected by the Kyoto Protocol that Canadian companies will be at a disadvantage in terms of trade. On May 31, 2002, all fifteen then-members of the European Union deposited the relevant ratification paperwork at the UN. The EU produces around 22% of global greenhouse gas emissions, and has agreed to a cut, on average, by 8% from 1990 emission levels. The EU has consistently been one of the major supporters of the Kyoto Protocol, negotiating hard to get wavering countries on board. Presently the increased EU member states have however inflated the volume of greenhouse gases emission by EU.
The partial exemption of China and India within the total frame work of the treaty is an argument for the US Government for not ratifying the protocol. China according to information from EIA, USA, recently put China energy-related usage as produced 3,541 million metric tons of CO2, while the U.S. produced 5,796 million metric tons [3]. This is expected to increase in the near future as the over 1.3 billion Chinese population and a staggering 1.1 billion populace of India and other economic emerging nations hit the road with automobiles.
The question on the quantitative effect of Man made (anthropogenic greenhouse effect) on global warming
has been raised time and time again. The 62 ppm increase on the concentration of CO2 in the atmosphere between 1960 and 2005 is basically man made. There will undoubtedly be a geometric increase in the years to come as more and more industrial activities and more importantly cars are mass produced by automotive industries.
Most of the cars produced in Europe and North America in the 60’s and 70’s are still in operation in places like Africa, Asia and South America. Some of these automobiles have literarily turned to “smoke” generating locomotives. In other wards these old vehicles simply changes position, and more cars hit our roads on daily basis. The long term cumulative effect is an increase in greenhouse gases and as such a shift in general global energy cycle.
As we probably cannot do without movement in our contemporary society and as some technologies (Hydrogen fuel cells, solar systems etc) that promises partial or zero emission of greenhouse gases are either so expensive or at the optimization level. Magnesium alloys application offers a reasonable way to greenhouse reduction from our automobiles. Magnesium is the lightest structural material on the face of the earth. The density of Magnesium measuring 1.8g/cm3 is about 4.5 times the density of steel and almost 2 times that of Aluminum alloys used in the present day automobile power train components. Its high strength to weight ration is an added advantage wherever weight compatibility is an issue.
Magnesia was first recognized by N. Grew in 1695, by 1722 F. Hoffman differentiated between magnesia and chalk. Subsequently, in 1755 J. Black recognized magnesium and calcium salts. In 1808 metallic magnesium was first isolated by a British chemist Sir Humphrey Davy through electrolysis of moist magnesium sulfate using mercury as cathode electrode [4]. Magnesium comprises of about 2% of the earth crust and occurs mostly as compounds.
Availability: Magnesium is abundant in nature mainly in seawater as positive ion, and in the terrestrial crust as magnesite (MgCO3), dolomite (CaCO3.MgCO)3 and many common silicates, as asbestors (H4Mg3Si2O9), talc (Mg3(Si4O10)(OH)2) and olivine ((Mg,Fe)2SiO4). The element also occurs as brucite (Mg(OH)2), carnalite (KCl.MgCl2.6H2O) and kieserite (MgSO4.H2O). From the above mention compounds, the most important minerals for magnesium production are: Magnesites, dolomites and carnallites that accounts for 27%, 13% and 8% of magnesium production respectively.
The seawater contains correspondingly 0.13% Mg or 1.1 kg Mg per m3 [5].Cast magnesium structures have the potential to reduce 100 kg of the total vehicle mass, which could reduce emissions by about 5% and improve fuel consumption by approximately 1.0 mpg (ignoring secondary mass savings) [6]. Generally the heavier the vehicles mass, the more fuel consumed and this simply means the more greenhouse gases are released in the atmosphere.
Exhaust gases are mostly made of carbon (as very small particles),unburned hydrocarbons, carbon dioxide, carbon monoxide, nitrogen oxides, sulphur oxides, water vapour, and thousands more “low-level” chemicals. Since most of the old cars in Europe and North America finally finds their ways in the developing world rather than being recycled, that simply implies that cars are basically increasing in geometric progression, the consequence is simply predictable. An application of magnesium alloy parts in less demanding areas where high temperature is not an issue like (brake pedal adapter, valve cover, engine cover assemblies, instrument panel, steering wheel armatures, lock housings, seat pans, seat risers and seat backs) is necessary.
Although creep resistance of magnesium alloys remains a major challenge for the power train parts (crankcase, automatic transmission housings, bed plates etc) and some exterior component applications. Some newly developed magnesium alloys such as AJ62, MRI153, MRI153M, MRI230D etc, exhibit good balance between key properties such as: good combination of mechanical and physical properties, excellent castability, good corrosion resistance, ease of handling, excellent characteristics of post process operations and be fully recycled [7, 8].
The adoption of this light material by automobile manufacturing companies in the industrialized nations will help to a reasonable extent in the reduction of greenhouse gases in the atmosphere. BMW auto manufacturing company is taking the lead in this area at the moment as 600,000 pieces of engine blocks was produced last year from AJ62.
The challenge of the contemporary research work in magnesium technology is therefore to continually improve the creep and corrosion resistance of magnesium alloys as these to a great extent offset its overall applicability. The maximization of this nature bestowed light material in the auto industries, substitution of the application of greenhouse gases in our industries, control burning of fossils and bushes will reduce greatly the anthropogenic generation of CO2 and other gases that could lead to global warming.
References
(Hansen, J., Climate Change, 61, 269, 2005).
(Science 308, 1431, 2005).
EIA (Energy Information Administration) USA, Home page.
4. Charles T.Lynch., Practical handbook of material science, 1989.
5. Kainer K.U., Von Buch F.; “The current State of Technology and potential for development of Magnesium applications”, Magnesium Alloys and Technology, Edited by Kainer K.U. (DGM), 2003. Page 1.
6. S. Xu, et al., “Bolt Load Retention Testing of Magnesium Alloys for Automotive Engine Cradle Applications”, Proceedings of the 2nd International Light Metals Technology Conference 2005, Ed. H. Kaufmann, pp. 283-288.
B. Bronfin et al., “Die Casting Magnesium Alloys for Elevated Temperature Applications”, Magnesium Technology 2001, Ed. J.N. Hryn, TMS 2001, pp. 127-130.
E. Aghion et al., “Dead Sea Magnesium Alloys Newly Developed for High Temperature Application”, Magnesium Technology 2003, Ed. H.I. Kaplan, TMS 2003, pp. 177-183.
Mr Anopuo studied Materials and metallurgical Engineering (B.Engr - |
