C-17 Globemaster III (IAF)

Discussion in 'Indian Air Force' started by A.V., Jun 15, 2009.

  1. IndiaRising

    IndiaRising Regular Member

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    IAF top bosses need some extra malai
     
  2. jadoogar

    jadoogar Regular Member

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    Well in respect to oil. The world (Paris climate accord) has decided to move away from oil. This is fairly easy to do for road transport if there is government backing. Thus if USA comes on board then oil consumption will be much lower implying that oil will be around for a long time.

    Also even if there is no movement out fossil fuels for road transport, oil will not run out. Rather it will get progressively more expensive. As that happens air transport will have to compete with other users (eg road transport) for available supplies. Even if there are no alternative fuels for air transport I expect that planes will still fly but at much higher ticket prices and potentially only on long routes.

    Coal can be converted to both kerosene and to diesel. Also to even lighter hydrocarbons (gasoline) at even higher cost.

    IMO when/if the world has burnt a lot more of the remaining oil and gas and has turned to producing liquid fuels from coal then the world would have become really hot (global warming).
     
  3. Kshithij

    Kshithij Regular Member

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    Can you explain why oil can't run out? Have you heard of EROEI? What kind of economics are you stating where can you value everything in money when money is just convention to value the production?

    Back to point-

    About commercial planes, read what I said and what you said. If oil is going to get too expensive, and the demand for airline ticket and hence demand for new airplane decreases drastically, why should India make commercial airplane? If there is going to be no demand for the existing planes itself, why do you expect demand for new entrants like India?
     
  4. jadoogar

    jadoogar Regular Member

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    EROEI: it is relevant if the input and output energies were in similar form. But there could be situations where the output form is useful enough that you can waste a lot of input energy - coal liquefaction could be one; producing liquid fuels from oil sands using stranded natural gas could be another.

    my discussion was academic - but also rambling so I apologize.

    I do think that the world will move off fossil fuels for road transport so I expect there to be plenty of fossil fuel for air transport for quite a while. Alternatives to power air transport may also develop.

    Whether the GOI should be funding civil passenger aircraft development - I do not know!
     
  5. Kshithij

    Kshithij Regular Member

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    Firstly, tar sands are liquid coal- they are kind of gooey substance - like toothpaste. They are intermediate between Petroleum and coal. Their refining is also similar to that of coal liquefaction but with higher output.

    The EROEI decreases in a bell curve (e^x) and eventually, input energy will be to high and unfeasible. The input today is Natural gas and not oil products. Even then, it is unfeasible to use 1 ton of natural gas to extract 1 ton of oil. In addition, refining of oil also needs energy and so does transportation of oil, oil products and natural gas. These additional overhead comes to about 15-20% of the energy for oil and 40% for gas.

    You are underestimating the amount of energy needed for transportation. For example, Indian coal liquefaction gives 1.3 barrels of liquids (1.2 barrels of fuel like kerosene and diesel) and 0.7 ton of solid. About 200kg of this solid is usable for burning to produce heat and electricity. But rest 500kg is waste. This 500kg per ton has to be dumped somewhere which also involves logistic cost like diesel for trucks/trains running.

    Coal liquefaction is definitely an alternative, but not a good alternative in terms of manpower and cost. Similarly, even tar sands are not a good alternative. Moreover, USA uses petrol and not diesel which also means a lot of natural gas is used to hydrogenate Tar Sands to produce petrol from diesel. This is additional use of resources.

    Also, the current usage of oil is 30 billion barrels a year and another 5 billion barrels a year of liquid condensate and 130TCF of gas. To replace all this with coal, one will need 50 billion ton of coal. Is it possible to extract this? Nope.


    That is exactly why I was saying that India only needs to develop military transport planes to replace imports and not transport cum civilian planes. Military planes are more robust, have short take-off and landing due to higher engine power and doesn't care much about fuel efficiency.

    The biggest problem with making a civil airliner is fuel efficiency. One has to continuously tweak the design which will be extremely cumbersome
     
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  6. jadoogar

    jadoogar Regular Member

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    You may be right that GOI should focus on military transports!

    Also true points about coal to liquids, oil sands to liquids etc....



    Also for those that may not know: EROEI is Energy Returned on Energy Invested - an acronym popular with the peak oil crowd of 2007-2008
     
    Last edited: Dec 2, 2017
  7. Kshithij

    Kshithij Regular Member

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    That is what I am saying. Since oil is running out and increasingly difficult ways have to be made to obtain fuel, the ability to make fuel in the needed amount is going to diminish. SO, even the current aircrafts will have to remain idle due to underbooking and lack of passengers.

    PS: I have edited my previous comment to add a few more lines to bring better context. Please read the last two-three paragraphs again.

    If you disagree, tell me why
     
  8. jadoogar

    jadoogar Regular Member

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    I do agree with the technical parts and conclusions of reply #845 above.

    However, in reference to availability of fuel for passenger air transport: 2 possibilities
    (1) Use fossil fuel kerosene as done now
    (2) use yet to be developed or existing alternatives. New ones could be development of a high capacity, light weight battery for example. Existing could be biodiesel

    (1): I do not have figures off hand but the vast majority of crude oil (30 billion barrels annual) is used for road transport. So if road transport goes electric then the world is now using a much smaller amount of crude for air transport implying that crude oil reserves will last much longer. In that case current air travel will continue and probably expand for a long time.

    Will road transport go electric ? - GOI has a stated policy of having sales of only electric cars by 2030. Electricity will be generated primarily by renewables like solar, wind with some baseload coming from nuclear plants.

    Europe is moving to electric and also incentivizing electric cars. So is China. I expect the rest of the world to follow suit, but do not know if / when the ROW will follow. I believe that most countries are parties to the Paris climate accord so they may follow.

    (2) Battery: we will have to wait and see what type of battery chemistry or other energy source comes out.
    Hydrogen: Perhaps hydrogen as fuel ? Can be produced limitlessly in sunny or windy areas by electrolysis. The conversion of hydrogen (+oxygen) energy to shaft power is the part to be developed -
    Biodiesel:- I do not know if this is a sustainable or cost effective solution.

    will these or other options work out ? I think that a way will be found but we can agree to disagree

    _------------------
    I do agree that India should focus on developing a transport plane, independently of developing passenger planes in the interest of speed, and because the requirements of a passenger plane and a military plane are likely different.
     
  9. Kshithij

    Kshithij Regular Member

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    Biodiesel means that you are cutting down forest or growing special crops (in place of food crops) like Jatropha to distill into diesel. Ask yourself if this is worth it. I, personally will rebel and riot against anyone who plans to wipe out the forest cover or reduce food production. I am ruling out biodiesel.

    Hydrogen has been tried before. Hydrogen was found to be extremely dangerous due to its ability to leak from containers. It needs some special lining of an expensive compound to prevent leakage. Hydrogen escapes from steel, concrete containers via the small pores at the rate of 1-3% per day, depending on pressure. This leaked hydrogen can catch fire too and destroy everything nearby including the container. Also, the problem with efficiency is glaring - the conversion efficiency of electrolysis is 80%, the compression efficiency is 75% (hydrogen has the lowest boiling point). The highest burning efficiency in power plant is 55% for CNG as of now. Assuming same foe hydrogen, the total efficiency from electrolysis to production of power comes to be - 0.8x0.75x0.55 = 33%. Now add transportation and storage efficiency factor. You will understand why hydrogen is inefficient to satisfy today's needs. It is possible to live like in 1940s with hydrogen, but not with this population of today.

    Battery is another day dream. Battery uses lithium which is not available in large enough quantities. Also, refining of Lithium is extremely hard and power consuming. This makes lithium battery a problem for efficient transportation. Also, these batteries weigh heavily and add unnecessary loads. They have low range and can't be used for transportation of goods. Tractor, trucks, taxi, tempos etc can't use battery. Next, power production for batteries requires coal power. Solar, wind are fluctuating and can't be used as reliable source of power. This has been tried in Germany and failed. Also, charging for 12hours will have to be done mostly in night when solar power won't work.

    Nuclear power is also non renewable. We are using nuclear power to generate only 10% if electricity of the world but using 1% of available resources. If we start using nuclear power to produce power for 80% of the electricity and also to power batteries for transportation, uranium will run out in less than 10 years.

    So, your petroleum substitution plan won't work. There is no feasible way. Civilian plane is a thing that will go down
     

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