I have seen tons of initiatives about using biofuels (like the ASTM D7566), but it is operative at large scale?, there is background info about demonstrative flights, but I don’t see a manufacturer or airline that is making use of the biofuel in regular basis.
It is a viable way of operate or it is a nonviable idea?
The "real" (or at least ideal) impact of biofuels in aviation is a reduction in CO2 emissions. When they burn, they produce exactly the same amount of CO2 as fossil fuels, but, all this CO2 came from CO2 that was already in the atmosphere. So it's only putting back what was already there:
From the standpoint of human-released carbon dioxide, other greenhouse gas emissions, and contributions to climate change biofuels have one large advantage over gasoline, diesel and other fossil fuels: The feedstocks for biofuels are part of the above-ground carbon cycle. Unlike petroleum or coal, the soybeans, corn, switchgrass and other biological materials that are made into biofuels are not dug up from underground, nor do they release long-stored carbon as carbon dioxide into the atmosphere when burned. Instead, when biofuels are burned, carbon dioxide they recently captured is release back into the atmosphere.
This is sometimes claimed to mean biofuels are carbon neutral. For example, it's claimed here a 95% reduction occurs. But it's a bit more complex than that:
Producing biofuel with crops like corn often requires converting land from food to fuel production or destroying natural ecosystems that provide valuable services, including carbon sequestration. Crops also require fertilizers, pesticides and large amounts of water, as well as machinery for planting, growing, harvesting, transporting and processing. If forests are cleared for fuel crops and if the entire lifecycle of the fuels is taken into account, biofuels don't always reduce overall greenhouse gas emissions. Palm oil, used for biodiesel, is especially bad, because valuable carbon sinks like peat bogs and rain forests are often destroyed to grow palms.
As noted by Wikipedia, bio-fuel remains more expensive than traditional fuels. A medium sized airline such as Jet Blue spends something like \$1 billion per year on fuel. So if bio-fuel is a mere 1% more expensive (i.e. a few cents as mentioned by Ron), that costs them an extra \$10 million per year.
Yes it is viable, but like all new processes will need to go through the cycle of R&D, then scaling up production and distribution, then obtaining economy of scale. Cost is always a driving factor in the succes of a product, both for businesses and consumers.
The traditional oil refining industry has a lead and experience of over a century in tackling and solving the problems associated with large scale logistics: there is a lot of aviation fuel that needs to be shipped and trucked around the world. They could start this in a time when they could focus only on economical problems, not environmental ones. Shell sold its refinery in the Netherlands Antilles in the 1980s: it was set up in the 1910s, supplied the majority of aviation fuel to the allied air forces in WW2, and was very much up for a total rebuild to comply with present day duty of care. A sale of the refinery for one dollar to the Venezuelan state oil company PDVSA was deemed the best solution at the time.
So biofuel logistics needs to tackle the same logistical problems that conventional logistics has a century old headstart in, using technologies untried at this scale, and will have much higher production costs than traditional processes. In countries where a large part of fuel cost is made up by taxes, the government can play a beneficial role here.
