HYDROGEN (H2) -FUEL OF THE FUTURE OR NOT ?

HYDROGEN (H₂ )-FUEL OF THE FUTURE OR NOT ?

Recently, the Indian Railways has announced to introduce the country’s first hydrogen-fuelled train.

In July 2021, The railways floated a tender for retrofitting the existing DEMU rakes into the green fuel-based train.
It will be introduced on the 89 km long Sonipat-Jind route of the Northern Railway.

Initially, two DEMU rakes will be converted, and later two Hybrid narrow gauge locos will be converted base on Hydrogen Fuel Cell power movement.

The conversion of diesel-powered DEMU will save costs to the tune of Rs 2.3 crore annually & also save the carbon footprint (NO2) of 11.12 kilo tons per annum and particulate matter of 0.72 kilo tons per annum.

After conversion, the train will run on hydrogen fuel, here hydrogen can be generated by electrolysing the water from solar energy.

So far, Germany and Poland are using this method of power generation in railways to run the trains.

This news creates curiosity to know about Hydrogen fuel system about its production, utilization & storage etc.

So in this post, I have tried to explain basic information about Hydrogen fuel technology.

I. ABOUT HYDROGEN FUEL CELL

Basically, it is a set of two electrodes of +ve & -ve nature. The blue Hydrogen has been flown on +ve terminal & Oxygen on  -ve terminal. Hydrogen comes from the storage tank & oxygen from Environment.

Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable:

2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ (286 kJ/mol)

Hydrogen gas forms explosive mixtures with air in concentrations from 4–74% and with chlorine at 5–95%. The explosive reactions may be triggered by spark, heat, or sunlight.

The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F).

After the reaction, the system produces water & electricity. The electricity used for the running of electric motor. Electric motors provide movement of the vehicle.

II. PRODUCTION OF HYDROGEN GAS

a. Electrolytic Processes

Water can be separated into oxygen and hydrogen through a process called electrolysis. Electrolytic processes take place in an electrolyzer.

2 H₂O(l) → 2 H₂(g) + O₂(g)

electrolyzer functions much like a fuel cell in a reverse system—instead of using the energy of a hydrogen molecule, as a fuel cell does, an electrolyzer creates hydrogen from water molecules.

b. Solar-Driven Processes

Solar-driven processes use light as the agent for hydrogen production. There are a few solar-driven processes, including photobiological, photoelectrochemical, and solar thermochemical.

Photobiological processes use the natural photosynthetic activity of bacteria and green algae to produce hydrogen.

Photoelectrochemical processes use specialized semiconductors to separate water into hydrogen and oxygen.

Solar thermochemical hydrogen production uses concentrated solar power to drive water splitting reactions often along with other species such as metal oxides.

c. Biological Processes

Biological processes use microbes such as bacteria and microalgae. They produce hydrogen through biological reactions.

In microbial biomass conversion, the microbes break down organic matter like biomass or wastewater to produce hydrogen, while in photobiological processes the microbes use sunlight as the energy source.

III. STORAGE & DISTRIBUTION

a. On-Site Production

As per demand & availability of raw material, Hydrogen can be produced by using above methods i. Electrolysis, ii. Solar-driven processes, iii. Biological processes

b. Dedicated pipeline Networks

A pipeline network is probably the best option if multiple customers are available for their industrial requirements. Several production facilities can feed Hydrogen (H₂ ) into the network of pipelines.

c. Hydrogen Pump Station

Cryogenic tanks can be provided to store the hydrogen in the case of Hydrogen Pump Stations.  The liquid hydrogen (LH₂) is efficiently stored in vacuum-insulated tanks which can be installed either vertically or horizontally.

Different capacities are available, ranging from 3,000 liters to over 100,000 liters. Big Hydrogen producing companies like LINDE offer transportable liquid Hydrogen ( LH₂ ) containers with active cooling with maximum safety.

IV. AMAZING FACTS ABOUT HYDROGEN

a. Availability

A huge amount of hydrogen is available in form of water, hydrocarbons, and other organic matter. Hydrogen can be produced from fossil fuels, biomass, and water electrolysis with wind, solar, or grid electricity.

b. Hydrogen Fuel Cell

It is just like a battery/cell, which produces electricity. Hydrogen Fuel Cell can be used for powering buildings, cars, trucks, electronic devices, etc.

Since fuel cells are grid-independent, they are also an attractive option for critical load functions such as data centers, telecommunications towers, hospitals, emergency response systems, and even military applications for national defense.

c. As Clean Energy Source

Fuel cells are similar to batteries for producing electricity without combustion or emissions. Unlike batteries, fuel cells do not run down or need to recharge as they have a continuous hydrogen-producing system. So they reduce carbon emission drastically.

d. Higher Energy Value

The energy in 2.2 pounds (1 kilogram) of hydrogen gas is about the same as the energy in 1 gallon (6.2 pounds, 2.8 kilograms) of gasoline. Because hydrogen has a low volumetric energy density, it is stored onboard a vehicle as a compressed gas to achieve the driving range of conventional vehicles.

V. CHALLENGES TO ADOPT HYDROGEN AS FUEL

a. Storage Cost

Since hydrogen is very explosive & highly flammable in nature. So Storing Hydrogen in tanks are very costly at the end.

b. Refuelling Cost

Since the storage of hydrogen is very expensive. The cost of Hydrogen gas is very high compared to conventional fuels. It demotivates the common persons to adopt it as fuel for their demands.

c. Availability of Pumps

Since the establishment of hydrogen, the pump station is very expensive compare to conventional fuels. So there are very few companies to establish the pump station.

References

1. https://en.wikipedia.org/wiki/Hydrogen

2. https://www.linde-engineering.com

3. https://www.energy.gov/eere/fuelcells/hydrogen-fuel-basics

4. https://www.freepressjournal.in/business/railways-plans-to-go-green-with-hydrogen-fuelled-trains

5. https://www.energy.gov/eere/articles/5-fast-facts-about-hydrogen-and-fuel-cells

6. https://www.visualcapitalist.com/6-ways-hydrogen-and-fuel-cells-can-help-transition-to-clean-energy/