The recent hike in the price of crude oil has resulted in soaring costs to airlines for fuel. As we mull these things over, some airlines are going out of business and even British Airways were quoted recently as planning to reduce their number of flights by one half over the next decade. It is odd, as I have remarked before, that there can consequently be any real justification for a fifth or even sixth terminal and a third runway at Heathrow Airport, since logic suggests there will be far fewer flights during the next decades than now, rather than the "three-fold expansion by 2030", that was flagged-up prior to the inauguration of Heathrow "terminal five". I don't see how conventional fuel can meet such demand in the face of unprecedented high costs, and worse to come according to many analysts, and an ultimate actual shortage of fuels, most likely during this same period.
I read the other day that it might be possible to make hydrocarbon "jet-fuel" from algae, of higher power-yield than ethanol or biodeisel, and which retains a satisfactorily low viscosity at the low temperatures encountered during routine flights in the altitudes of the troposphere. In contrast, iiodiesel becomes highly viscous (thick) when cooled and difficult or impossible to pump around an engine. However, this technology is still at an experimental stage and certainly is unlikely to solve the problem of how to keep aviation running in the face of an inevitable loss of cheap, plentiful plane-fuel. The same conundrum also applies to terrestrial vehicles, of course.
As in any potential shortfall between supply (earnings) and demand (expenditure) , the gap can be narrowed from either side: i.e. you can, in principle at least, earn more or you can economise, and spend less. So it is with plane-fuel. Knowing that there will never be cheap fuel again, the airlines are looking toward designing planes that use fuel far more efficiently. However, even if more fuel-efficient planes can be built, there remains the matter of what materials they will be made from. This brings on another resource issue, namely that of rare metals.
Metals such as rhenium, chromium, cobalt and titanium, which are already in demand to make industrial catalysts and other essential items for a variety of purposes, including fuel-production from crude-oil distillation fractions, are needed on a large scale to make new super-alloys for planes. The price of rhenium has jumped to a record $11,250 per kilogram, which is almost twelve-times its price in 2006. Indeed, it is now only half the price of gold, which is a big plus to those countries that mine rhenium-ore, e.g. Chile and Kazakhstan.
Rhenium and other rare metals are readily blended with other more common metals, to form alloys which are highly heat-resistant, and allow aircraft engines made from them to run at much higher temperatures than normal, so increasing the thermal-efficiency of the engine. The Carnot-cycle depends on the temperature differential between the coolest and the hottest working part of an engine and so if the latter can be increased, more miles are obtained per gallon of fuel.
Rhenium-alloys have been used in military planes for decades but the move on them by the commercial sector is new. During the cold-war both the US and the Russians stockpiled such materials specifically to keep their war-plane fleet provided for. The drive toward fuel-economy will force-up the price of rare metals as rival airlines battle it out in order to stay in business.
Chromium is mined and produced mostly in South Africa, which has seen its price rise from $4,000 a tonne in 2000 to $11,000 a tonne now. The price was just under $7,000 a tonne only last year. It is interesting but probably unrelated that this is close to the ratio of oil-prices between now and a year ago. Cobalt is produced mostly in the Democratic Republic of Congo (formerly the Belgian Congo), and now costs about $52.50 a pound, which is double its 2006 value.
Along with many resources, most metals are now being stretched into a supply-demand gap, as the world requires more and more of them, and we see this being reflected in their price. In many cases, it is not that there is insufficient of a particular material in the Earth but its rate of production is limited in the face of demand. For metals such as hafnium, vital both in the nuclear and electronics industries, there is a real shortage of known world-reserves, which only the discovery of new ore-deposits or the implementation of an efficient recycling strategy will serve to ease.
"Rare metals soar on demand for efficient jets." By Javier Blas. http://www.ft.com/cms/s/0/a0c9877a-3c91-11dd-b958-0000779fd2ac.html