Green AAG

Green AAG: A Sustainable Fuel Alternative

Introduction to Green AAG

Yes we are here to introduce an alternate, pollution free, energy efficient, convenient, dependable and sustainable fuel that will cost you cheaper than that of any of the prevailing fossil fuel or bio fuel. Since the inception of human civilization we have traveled a long journey of development and technological advancements as pre the requirements of time, that is to say human mind have enormous capabilities for innovations and developments of new technologies as and when the need is arises.

Energy is our basic need in every walk of life and we have been utilizing different sources of energy to cater our requirements, one of the most prominent source of energy is fossil fuels (petroleum oil, petroleum gases and coal) which are serving our energy needs for a long time but these sources are depleting at alarming rates, and yes they are also posing the problem of atmospheric pollution. Now a days the air pollution caused by the fossil fuels has have posed a potential menace for humanity and mother planet, there are all around awareness and consideration concerned with atmospheric pollution.

The maximum amount of fossil fuel is used in our transportation systems that are commonly propelled by an IC Engine hence the contribution of this sector in atmospheric pollution is greater than others.

CO2 Emission of Different Fuels

The Need for Sustainable Energy

Now we are compelled for development and adoption of a sustainable and pollution free source of energy. We are striving already in this direction and have been trying different sources in the past some are considered here.

Alternative Energy Sources

Solar Energy

As we all know that SUN the ultimate source of energy no doubt, but here we are considering here fuel of our automobiles, and here it may be impractical to operate a vehicle directly on solar energy.

Wind, Geothermal, and Hydro Power

These are also source of green and renewable source of energy but there is also the same problem of impracticality as of solar energy with transportation and automobile sector.

Biofuels

Someone might think that ‘ethanol’ and ‘biodiesel’ are the ultimate green fuels. But these are not pollution free indeed, and never lead to Decarbonize our energy system. More over Biodiesel and Bio-CNG do emit the same quality and quantity of exhaust gases as that of the respective counterparts from fossil resources. They are renewable sources but there is no way to grow enough bio-fuel feedstock for this kind fuel to displace petroleum consumption to any great extent.

As crops are grown for fuel rather than food, this diversion of resources places upward pressure on the price of food. Please refer to an interesting CBC article about agricultural prices as well as the OECD report entitled "BIOFUELS: IS THE CURE WORSE THAN THE DISEASE?"

The OECD has said bio-fuels may "offer a cure that is worse than the disease they are seeking to heal". In addition they are not green fuels as there is almost the same amount of pollution as of petroleum fuel.

Hydrogen Fuel

The holy grail of "green fuels” is hydrogen, an element that is also very scarce in its pure form on earth. Green in the sense that it is produced from renewable sources, hydrogen may also be produced from "brown" sources such as the refining of petroleum. However hydrogen can be produced by different sources solar, wind, hydro and geothermal powers, to be utilized in vehicular fuel which will cause no pollution and can deliver green energy. Some companies are engaged to develop fuel-cell for this purpose and IC Engines can also be modified to burn hydrogen with about 28 – 32% fuel efficiency. There is no problem at all. But it poses the problem in some other way.

Problems with Hydrogen as Fuel:

• Cost of hydrogen fuel cell stock is very high that make the vehicle beyond the reach of common people.
• Cost and weight of on board storage cylinder for gaseous hydrogen.
• Cost of transportation and storage: - Hydrogen is typically transported as a compressed gas and a 40 ton truck that can carry 26 tons of gasoline can only carry about 400 kg of compressed hydrogen due to the weight of the high pressure hydrogen tanks.
• Hydrogen Embrittlement: - This is unique property of hydrogen, because of its smallest size it penetrates between the molecular spaces of the metals, weaken them, and make them brittle, thus metallic cylinders may fail to contain hydrogen on such a pressure of more than 5,000 psi in long run of time.
• Hydrogen's physical properties make it very difficult to handle. Because it is such a low density gas, very high pressures must be used to transport compressed hydrogen gas and this results in very low energy densities 1,825 kJ/litre gas @ 200 bar g & 15 ºC 4,500 kJ/litre gas @ 690 bar g & 15 ºC
• The low energy density of compressed hydrogen gas makes storage and transport very expensive. Transporting compressed hydrogen gas any significant distance by truck can consume more energy in diesel fuel than what is contained in hydrogen. Liquefied hydrogen is obviously more energy dense than compressed hydrogen gas but a significant amount of energy must be expended to liquefy hydrogen and keep it refrigerated because its boiling point is –423 ºF (–253 ºC). Liquefaction requires about 30% of the energy content of liquid hydrogen while compression to 800 Bar requires about 10-15% of energy carried by the hydrogen.
• Hydrogen's molecules are very small and difficult to contain. Hydrogen will slowly leak out from hoses and its rate of leakage is much higher than larger molecule gases like ammonia and propane. Hydrogen also causes embrittlement in metals which requires periodic replacement of metallic tubing, valves, and tanks. Hydrogen is typically transported as a compressed gas and a 40 ton truck that can carry 26 tons of gasoline can only carry about 400 kg (0.4 tones) of compressed hydrogen due to the weight of the high pressure hydrogen tanks.

AAG (Anhydrous Ammonia Gas)

Then comes in the consideration “AAG” the Anhydrous Ammonia Gas that poses no problem as of hydrogen related to storage and transportation it can be liquefied by moderate pressure as of LPG and in addition the hydrogen density in liquid AAG is 150% to the liquid hydrogen itself. Thus on a volume basis AAG is a much better hydrogen carrier than even liquefied hydrogen. The energy density of liquefied hydrogen is 8,491 kJ/ liter compared to ammonia's 11,308 kJ/ liter. Although ammonia contains 17.65% of hydrogen by weight, the fact that there are 3 hydrogen atoms attached to a single nitrogen atom allows ammonia to contain about 48% more hydrogen by volume than even liquefied hydrogen.

Conversion of Hydrogen into Ammonia

1 kg H2 yields 5.66 kg ammonia that is to say in energy terms 121 MJ energy of hydrogen can be converted into 117 MJ energy of ammonia.

Thus AAG is the practical and affordable fuel for pollution free “Hydrogen Economy” that is seemingly better source of green energy that can easily be synthesized with hydrogen and nitrogen but it also has its gray facet, here on this site we will consider different aspects of this.