To Curb Pollution Delhi Turns to Hydrogen Power for Future Buses

The Supreme Court of India has asked the Delhi Govt to try Hydrogen blended CNG in DTC buses. HCNG may come in soon.

Low floor CNG buses have been running in Delhi since 2001.

(Photo: iStock)

We have been talking about the rising pollution levels in Delhi and how it’s getting hazardous for a while now. To curb pollution, the Delhi government is planning to push HCNG fuel on DTC buses which is a blend of hydrogen and CNG (compressed natural gas).

Though the earlier plan was to procure electric buses, it seems that plan has taken a detour and now the government is ready to push a pilot that will involve 50 buses running on HCNG fuel.

This move has come into effect after the Supreme Court has directed the Delhi government to introduce zero-emission and cost-effective buses for Delhi roads. But, is Hydrogen power fuel really effective and what happens to the buses already running on Delhi roads?

What is HCNG?

Hydrogen as a resource is considered to be the most promising fuel for the automotive sector. Being number one on the periodic table, it is one of the most combustible as well. Not something to be played around with.

It’s the same fuel that’s used to power space rockets and is very powerful. The only reason that the government has considered to use this fuel, blended with natural gas, is because it has very few emissions and increases the performance of the automobile.

HCNG is a mix of hydrogen and CNG. This fuel contains 18 percent of hydrogen while the rest of it is compressed natural gas. The Hydrogen is extracted from methane and is blended with CNG to create a gas, which has far fewer carbon emissions than CNG.

Why the Government Is Pushing for Hydrogen Based Fuels?

Apart from the fact that HCNG is a cleaner source of fuel, it is also more powerful and offers more mileage. Almost 4-5 percent higher.

Many researchers have shown that the thermal efficiency of both natural gas and HCNG increases when the load it carries increases simultaneously, which makes it an ideal fuel for high load applications and heavy-duty vehicles: In this case, DTC buses.

It’s just not HCNG that the government is pushing but it’s also looking to promote companies who are willing to offer vehicles that are fully running on hydrogen fuel cells as well. In 2015, Tata Motors had launched its own bus powered by hydrogen fuel cells dubbed Starbus Electric /Hybrid.

To further aid this cause, IOL ( Indian Oil Corporation ) has a laboratory of its own that produces HCNG and is India’s first Hydrogen filling station. It’s a start for bigger things to come.

What Happens to the CNG Buses Already on Delhi Roads?

Before the proposal for HCNG came into the picture, the government had already informed the court that it was looking to purchase 1,000 electric buses wherein the court intervened and said that it was better to consider hydrogen as an option.

It’s very clear that the green DTC buses on the roads of Delhi aren’t going anywhere as later a senior government official said they are looking to introduce HCNG technology in the current fleet as getting hydrogen buses is difficult.

Currently, they are planning to implement this in 50 buses for which dispensing infrastructure would be installed at one depot. The official also said that they would need to modify the current fleet slightly to use this fuel.

What are the Challenges for Implementation of HCNG?

Hydrogen might be one of the most ubiquitous gases on the planet, but even then there are challenges that stand in the way of using hydrogen as a fuel source.

The biggest challenges in using HCNG for buses is determining the most optimised hydrogen/compressed natural gas ratio.

If the hydrogen fraction increases above a certain limit, it will result in abnormal combustion such as pre-ignition, knock and backfire, unless the spark timing and air-fuel ratio are meticulously adjusted.

Seemingly, the most obvious challenge is the is the lack of infrastructure to make and distribute a fuel like this. Also, just like other gaseous fuels, both natural gas and hydrogen are lighter than air which means that if there is a leak it will quickly disperse into air. So proper storage options is also a challenge.

Lastly, the current cost of hydrogen is higher than that of natural gas which means HCNG is going to be more expensive than CNG.