After a successful experimental run with CNG, Indian Railways has set its eyes on LNG as an alternative fuel option. The transporter is awaiting regulatory approvals for conducting trials.

LNG requires less storage space than CNG which makes it a more efficient and convenient option. By storing LNG in the same space as CNG, trains can run for three times the distance, according to experts. The CNG experiment was conducted on 21 trains.

LNG is already being tried out in other countries, including Russia, North America and Spain.

The CNG experiment

Of the trains running on CNG, 20 are in the Northern Railways and one in Vijayawada region (South Central Railway). A decision on scaling up CNG train-run experiment depends on whether more refuelling stations can be set up.

Theoretically, use of CNG resulted in 8-11 per cent savings against a similar train running on diesel. However, in CNG-based trains, the Railways has fitted cascades, a group of cylinders, with storage space for CNG that takes away the space equivalent to a third of a full coach. Replacing the energy storages with seats, would have resulted in extra revenue for the Railways.Now, it wants to try out LNG as alternative fuel and estimate the savings it can make.

LNG scores over CNG in several areas including space required for storage which means a train can run for a longer distance with the same amount of LNG. “In the space allocated for CNG storage in trains, Railways can store LNG, which will generate three times the energy. In simple terms, same amount of LNG stored in the space meant for CNG can haul a train for a much longer distance without requiring refuelling, and thus without having to stop,” Subodh Kumar Sagar, Chief Mechanical Engineer, Indian Railways Organisation for Alternate Fuels (IROAF), said in a conference recently.

Regulatory nods

Railways needs a regulatory mechanism to install the storage in trains, and in terminals, from Lucknow-based Research Designs and Standards Organisation (RDSO) and Nagpur-based Petroleum Explosive Safety Organisation.

The Railways now requires a network of LNG fuelling points to ensure refuelling capacity.

Trial run

For the trials, the Railways mulls attaching an LNG tanker to a train which can be refuelled at end of the journey. The cost-benefit analysis is yet to be finalised. Based on early estimates, a railway official explained, “Installing an LNG tanker will require 30 per cent higher capital expenditure than CNG, while the running cost of LNG will be cheaper by 40 per cent.”

The biggest expenditure will be on the refuelling infrastructure, which will have to be decided at a national level. The refuelling infrastructure requires points for storage, retail, decantation, and filling the tanks.

“Railways had increased its adoption of biodiesel in fiscal 2015-16 and 2016-17 which dropped in 2017-18. This dip can be attributed to GST implementation which impacted biodiesel makers. Biodiesel became more expensive than diesel,” shared an official.

Another alternative energy that Railways has started adopting is solar, both at stations and on trains.. Flexi-solar panels for trains, developed by a public sector unit Central Electronics Limited, are able to generate enough power to meet light and fan requirements of coaches.