Context: Union Minister for Petroleum and Natural Gas has dedicated to the nation India’s first small scale liquified natural gas (SSLNG) unit at GAIL (India) Ltd.’s Vijaipur complex in Madhya Pradesh.
Need for Small Scale LNG
- Government Ambition: Government aims to increase the share of Natural gas in its primary energy mix to 15% by 2030 from a little more than 6% at present.
- Reduction in Pollution: Natural gas is far less polluting than conventional hydrocarbons like coal and oil.
- Reduce import burden: Natural gas is cheaper than oil (85% of oil requirement comes from imports). Replacing a major chunk of diesel consumption by LNG could lead to substantial foreign exchange savings.
- Transition fuel: Natural gas is seen as a key transition fuel in India’s journey towards green energy and future fuels.
- For scaling up consumption: Large scale pipeline projects that are in the works will take years to be completed; even so, last mile delivery challenges may persist in many parts of the country.
- More mileage: LNG offers a slightly longer range to vehicles with similar sized fuel tanks.
What is Small Scale LNG?
- It refers to the liquefaction of natural gas and its transportation using unconventional means in a significantly smaller scale operation than the usual large-scale liquefaction, regasification, and the transportation infrastructure and processes.
- Simply put, LNG-gas in its liquid and super chilled form is supplied in specialized trucks and small vessels to industrial and commercial consumers in regions that are not connected by pipelines.
- In a relatively traditional use case, such as supplying compressed natural gas (CNG) for vehicles and piped gas for households and manufacturing units, the buyer would regasify the LNG using small vaporizers and then supply to end users.
- Where the fuel is to be used directly in its liquid form, it would be supplied to end users without regasification.
- The SSLNG chain can start from a large-scale LNG import terminal from where the LNG, instead of being regasified and supplied through pipelines, can be transported to consumers by cryogenic road tankers or small vessels.
- The chain can also start at locations with ample natural gas supply or production, where small liquefaction plants can be set up.
Working of SSLNG
- There are two treatment skids:
- Zeolite pre-treatment skids: It is used to process natural gas at a pressure of 15 bar to remove non desirable components such as nitrogen, water, Sulphur, and Carbon di oxide.
- Liquefaction skids: known as cryo box for converting natural gas to LNG at pressure of around 260 bar.
- The gas is cooled by a propane based external refrigeration system to minus 60-70 degrees Celsius, and then subjected to expansion, such that the temperature falls below minus 140 degrees Celsius allowing it to liquify.
- The LNG will then be dispatched by cryogenic tankers to nearby areas for use in city gas distribution networks as CNG and piped gas, and in LPG filling stations for medium and heavy vehicles.
- The SSLNG unit is controlled by an automated, web based supervisory control and data acquisition (SCADA) system, a mechanism that is typically used to monitor large industrial devices and processes.
Challenges for India
- Lack of easy availability of LNG powered vehicles.
- High initial cost of LNG based vehicles as compared to diesel and petroleum-based vehicles.
- Absence of an LNG vehicle financing system.
- The nonexistence of LNG retail network.
Efforts taken
- Petronet has collaborated with commercial vehicle manufacturers and other public sector oil and gas companies for trials and pilot projects for LNG- fueled trucks and buses.
- Petronet has established a few LNG dispensing stations along highways.
- GAIL is looking to build LNG dispensing stations along major highways.