India’s First LNG-Diesel Dual-Fuel Train

India’s First LNG-Diesel Dual-Fuel DEMU Train Launched

Why in News?

• Indian Railways launched the country’s first LNG-diesel dual-fuel DEMU train from Sabarmati, Gujarat, on September 27, 2026. 
• The train can run on both Liquefied Natural Gas (LNG) and diesel, allowing LNG to replace around 40% of diesel consumption. 
• The initiative aims to reduce fuel costs, diesel dependence and emissions from railway operations. 

Key Features

• Two 1,400 HP Driving Power Cars (DPCs) at Sabarmati were converted for the project. 
• More than 2,000 km of field trials have been completed. 
• The inaugural service operates between Sabarmati and Mahesana Junction. 
• Each DPC has an LNG tank of around 2,200 litres, holding nearly 950–1,000 kg of usable LNG. 
• One DPC can travel approximately 444 km on a full LNG load. 

Expected Benefits

• Lower diesel consumption: LNG can partially replace diesel. 
• Reduced emissions: LNG combustion generally produces lower particulate matter, sulphur oxides and nitrogen oxides than diesel. 
• Lower operating costs: Greater LNG use can reduce fuel expenditure. 
• Energy diversification: Promotes natural gas as an alternative transport fuel. 
• Dual-fuel flexibility: The train can continue operating on diesel when LNG availability is limited. 

What is LNG?

• LNG is mainly methane (CH₄) cooled to about −162°C to convert it into liquid form. 
• Its volume becomes about 600 times smaller, making storage and long-distance transportation easier. 
• LNG is a fossil fuel, not a renewable energy source. 
• Methane leakage during production and transportation remains an environmental concern. 

Hydrogen Train vs LNG Train

• Hydrogen train: Uses hydrogen fuel cells to generate electricity; water vapour is the direct by-product. 
• LNG train: Uses a modified internal-combustion engine running on both LNG and diesel. 

Practice Question 

Q. Consider the following statements regarding India’s first LNG-diesel dual-fuel DEMU train:

1. The train uses a dual-fuel system in which LNG can partially substitute diesel, while diesel can still be used when LNG availability is limited. 
2. LNG is produced by cooling natural gas to approximately −162°C, reducing its volume to nearly one-six-hundredth of its gaseous volume. 
3. Unlike a hydrogen fuel-cell train, the LNG-diesel train generates electricity through a fuel-cell reaction between LNG and oxygen. 
4. The use of LNG can reduce particulate matter, sulphur oxides and nitrogen oxides compared with conventional diesel combustion. 

Which of the statements given above are correct?

(a) 1 and 2 only
(b) 1, 2 and 4 only
(c) 2, 3 and 4 only
(d) 1, 3 and 4 only

Answer: (b) 1, 2 and 4 only

Explanation:

• The LNG-diesel DEMU uses a dual-fuel system, allowing LNG to replace a part of diesel consumption while retaining diesel as an alternative fuel. Hence, Statement 1 is correct. 
• LNG is produced by cooling natural gas to about −162°C, and its volume becomes nearly 600 times smaller than in its gaseous state. Hence, Statement 2 is correct. 
• The hydrogen train uses a fuel-cell system involving hydrogen and oxygen, whereas the LNG train uses a modified internal-combustion engine operating with LNG and diesel. Hence, Statement 3 is incorrect. 
• LNG combustion generally produces lower levels of particulate matter, sulphur oxides and nitrogen oxides than conventional diesel combustion. Hence, Statement 4 is correct.