Aviation sector under scanner

India may soon join the European Union (EU) in efforts to reduce emissions from its aviation industry. The country’s Directorate General of Civil Aviation (DCGA) earlier this month required that the civil aviation sector begin monitoring all carbon emissions from airports to create a national carbon inventory.

All airlines and airports will have to track their emissions over the course of 2011, and must submit the data to DGCA by January 2012. This data will then be used to estimate the total aviation industry’s carbon footprint, develop a national emission inventory for the Indian aviation sector, and potentially serve as a point of reference to reduce emissions in the future.

Under the EU system, all airlines (even foreign ones)would have to account for their emissions and participate in a permit trading system for every ton of CO2 they emit or face fines. India has asked its major airlines to refuse turning over emissions data to the EU, and estimated it would cost Indian carriers $57 million in 2012.

The IPCC has estimated that aviation is responsible for around 3.5% of anthropogenic climate change, a figure which includes both CO2 and non-CO2 induced effects. In addition to the CO2 released by most aircraft in flight through the burning of fuels such as Jet-A (turbine aircraft) or Avgas (piston aircraft), the aviation industry also contributes greenhouse gas emissions from ground airport vehicles and those used by passengers and staff to access airports.

For example, in EU emissions from aviation increased by 87% between 1990 and 2006. Reason enough to take aviation emissions seriously.

Hydrogen for Boeing

Boeing is developing an unmanned plane that would use liquid hydrogen to reach altitudes topping 60,000 feet and stay there for days at a time.

The plane is one of several alt-fuel aircraft that Boeing, which earlier this year tested a hydrogen fuel cell airplane, is working on. It uses an internal combustion engine which burns hydrogen. It has been tested on the ground in the lab under the high altitude conditions.

As it gives out mostly water vapour, which is also a greenhouse gas, but does not have carbondi oxide’s staying power and only has a minor direct warming effect, hydrogen could be considered a better fuel than the normal aviation fuel. It is also light.

Liquid hydrogen is used in rockets where it is mixed with oxygen and burns. The problem with liquid hydrogen needs much more volume than other fuels to store the same amount of energy. It takes roughly four liters of LH2 to match the energy content of one liter of jet fuel. The fuel cannot be carried in the wings as it will have to be large and will affect the lift. Boeing plans to try the fuselage for storing the fuel.

Combustion of fuel in aeroplane engines results in emissions of carbon dioxide (CO2) and nitrogen oxides, (termed NOx), as well as water vapour and particulates. Aviation emissions have a greater potential for mischief as they can instigate various chemical changes at that height. It is the emission of NOx, water vapour and particulates at altitude that account for the extra impacts of aviation emissions. Nox also combines with sunlight to form ozone.

Aviation is the fastest growing cause of global warming. The amount of carbon dioxide emitted by air travel doubled between 1990 and 2004. That is totally incompatible with the need to reduce carbon emissions by 60% by 2050.

But it is not possible to ask people not to fly or to make it a costly option just to cut down on flights. A better solution touted is to improve fuel efficiencies, the air traffic control gets smart, routes get straighter, etc. All these with a proper implementation of emissions trading on aircrafts and research on friendlier fuels can bring down fuel used and emissions.

Biofuel powers flying car

Caught in traffic jams, what do most of us wish for? Simply that we could fly over the gridlock, right? In an exercise that could possibly make that wish come true, an engineer designer team in Britain has come up with a Skycar that flies using technology already existing.

The buggy uses a motorcycle engine modified to run on ethanol. The car has a wing and a big fan attached to its back, besides a parachute for emergency landing.

The Skycar’s abilities will be tested to limit later this month when two explorers set off from London in the propeller-powered dune buggy heading for the Sahara.

While the fan gives the initial thrust for take-off, cables attached to the wing help steer the car once in the air where it cruises at altitudes of 2500 ft. Not costing more than a BMW saloon, this may not be the ideal solution for everyday transport. The jams will merely be lifted from ground level! But this could be ideal for ambulances, or rescue operations.

Using ethanol is an advantage as the emissions are not damaging. At least not as damaging as normal aviation fuel which emits nitrogen oxides that leads to the formation of another greenhouse gas, ozone. Condensation trails, which can develop into cirrus clouds, may also have a warming effect. International experts say aviation will account for 5% of total warming in 2050.

An alternative fuel that is eco friendly is hydrogen, but aircraft able to run on this fuel are still at a conceptual stage. Biofuels like the one our Skycar uses could save the day. Or do they?

While biofuels have been taken up aggressively, are they the best option? It is a solution to the transport fuel and nations pursuing biofuel research are spurred more by energy independence than clean fuel.

Last year, a study had found that emissions from the burning of biofuels derived from rapeseed and maize produce more greenhouse gas emissions than they save. Rapeseed and maize biodiesels were calculated to produce up to 70 per cent and 50 per cent more greenhouse gases respectively than fossil fuels. The concerns were raised over the levels of emissions of nitrous oxide, which is 296 times more powerful as a greenhouse gas than carbon dioxide. Scientists found that the use of biofuels released twice as much as nitrous oxide as previously realised.
The research is published in the journal Atmospheric Chemistry and Physics, where it has been placed for open review.

What has been your experience on biofuels? Let us know. We will be taking this up in our next few posts.