Image Source Feb 19, 2021 22:55 IST · 3 min read
India has announced a National Hydrogen Mission in the Budget - a roadmap for using hydrogen as an energy source, with specific focus on green hydrogen.
Hydrogen has the potential of transforming transportation industry, which contributes a third of all greenhouse gas emissions. It is being seen as a direct replacement of fossil fuels.
Delhi became the first Indian city to operate buses running on hydrogen spiked compressed natural gas (H-CNG). Indian Oil Corp has patented a new technology for producing H-CNG (18 percent hydrogen in CNG) - directly from natural gas, without resorting to conventional blending.
In 1937, the German passenger airship LZ129 Hindenburg used hydrogen fuel to fly across the Atlantic, only to explode while docking, killing 36 people. In the late 1960s, hydrogen fuel cells helped power NASA's Apollo missions to the moon.
Hydrogen exists only combined with other elements, and has to be extracted from naturally occurring compounds like water (H2O). Although hydrogen is a clean molecule, the process of extracting it is energy-intensive.
The bulk of the hydrogen produced today is obtained from fossil fuels, called grey hydrogen. Hydrogen generated from fossil fuels with carbon capture and storage options is called blue hydrogen.
Green hydrogen is generated entirely from renewable power sources, in this process electricity generated from renewable energy is used to split water into hydrogen and oxygen.
One of the colossal challenges faced by the industry for using hydrogen commercially is the economic sustainability of extracting green or blue hydrogen.
EV push may be counterproductive for India
In several countries that have gone in for an EV push, much of the electricity is generated from renewables - in Norway. it is 99 per cent from hydroelectric power.India's electricity grid is predominantly coal-based and will continue to be so, thus negating collateral benefits from a large-scale EV push - as coal will have to be burnt to generate the electricity that will power these vehicles.
Hydrogen fuel cells
A fuel cell converts chemical energy into electrical energy using oxidising agents through an oxidation-reduction reaction.Inside each individual fuel cell, hydrogen is drawn from an onboard pressurised tank and made to react with a catalyst, usually made from platinum. As the hydrogen passes through the catalyst, it is stripped of its electrons, which are forced to move along an external circuit, producing an electrical current.
This current is used by the electric motor to power the vehicle, with the only byproduct being water vapour hence near zero carbon footprint.
Hydrogen is about two to three times as efficient as burning petrol, because an electric chemical reaction is much more efficient than combustion.
Electric vehicle types
1) Conventional hybrid (HEVs)
It combine a conventional internal combustion (IC) engine system with an electric propulsion system, resulting in a hybrid vehicle drivetrain that substantially lowers fuel usage. The battery is charged when the IC engine is powering the drivetrain. e.g. Toyota Camry.2) Plug-in hybrid (PHEVs)
A hybrid drivetrain that uses an IC engine and electric power from rechargeable batteries which can be plugged into a power source. e.g. Chevrolet Volt.3) Battery powered (BEVs)
No IC engine or fuel tank, and run on a fully electric drivetrain powered by rechargeable batteries. e.g. Tesla Model S.4) Fuel cell electric vehicles (FCEVs)
Hydrogen and oxygen to produce electricity, which runs the motor. Since they're powered entirely by electricity, FCEVs are considered EVs, but unlike BEVs, their range and refuelling processes are comparable to conventional cars and trucks.What is Hydrogen fuel ?
Hydrogen is the lightest and first element on the periodic table. Since the weight of hydrogen is less than air, it rises in the atmosphere and is therefore rarely found in its pure form, H2.Hydrogen is the most abundant element in the universe, the sun and other stars are composed largely of hydrogen.
Molecular hydrogen is not available on Earth in convenient natural reservoirs. Most hydrogen on Earth is bonded to oxygen in water and to carbon in live or dead and/or fossilized biomass.
Hydrogen can be stored physically as either a gas or a liquid.
At standard temperature and pressure, hydrogen is a nontoxic, nonmetallic, odorless, tasteless, colorless, and highly combustible diatomic gas.
Hydrogen fuel is a zero-emission fuel burned with oxygen. It can be used in fuel cells or internal combustion engines. It is also used as a fuel for spacecraft propulsion.