Advantages as alternative fuel
The use of liquefied natural gas as a rail fuel has a number of advantages:
- It contributes to the reduction of environmental pollution and the emission of nitrogen oxides (NOx), particulate matter (PM), oxides of sulfur and carbon monoxide (CO).
- It avoids noise pollution and greenhouse gases.
- It exceeds the new environmental requirements to be applied in the railway sector.
- Compared with diesel, a reduction between 20 and 30% of carbon dioxide (CO2) emissions is foreseen; between 70 and 90% of carbon oxide (CO) emissions; 99% in sulfur dioxide (SO2) and 90% in particles.
- It can reduce operating costs in relation to other petroleum fuels.
- It allows overcoming the energy dependence of these sources.
- It is an alternative to the investment in electrification of non-electrified sections.
Application of LNG in rail transport in the EU and Spain
The environmental impact of dieseland the rise in its cost motivate the search for alternative sources of energyin the rail sector, such as liquefied natural gas (LNG). In the European Union,this technology requires a feasibility study to facilitate its implementationon a large scale.
The innovation project in railway traction analyzes this viability in the adaptation of rail vehicles for operation with engines and LNG tanks. It also includes the technical, legal, economic and environmental analysis for the Spanish and European rail network.
The NFPA 52 “Vehicular Natural Gas Fuel Systems Code” in its 2016 edition eliminates the restrictions that existed in previous editions prior to the application of LNG in the railway case. This facilitates the development of a specific regulation applicable to the use and transportation of LNG by rail.
In Spain, the improvement of transport from the energy and environmental point of view is enhanced through the plan for decarbonisation and energy efficiency of rail transport, driven by Renfe and Adif. In addition, the strategy of driving the Vehicle with Alternative Energies (VEA) in Spain 2014-2020 is part of the framework of application of 2014/94 Directive on the implementation of an infrastructure for alternative fuels in Europe.
According to data obtained by the Ministry of Energy, the railroad consumes almost half of the electricity used in transport in Spain (45.8% versus 20.1% on the road). In addition to maintaining the electrification of the railway, we should bet on other formulas. Logistics and technology of storage and refueling of LNG available allow the supply to different railway segments with alternative engines in powers of up to 400 hp.
In 2013, Gas Natural Fenosa, Enagás and Cepsa commissioned a study from the Institut Cerdà to evaluate the technical, legal and economic feasibility of using liquefied natural gas in railway traction. In this study it was identified that the railway traction with LNG implies the simultaneously overcoming of three phases:
- Phase 1: Adaptation to the traction technology with LNG.
- Phase 2: Creation of supply facilities.
- Phase 3: Maintenance.
After the development and study of these phases, in 2015 positive conclusions were obtained. This led Gas Natural Fenosa and Enagás to sign a collaboration agreement with Renfe for the development of a pilot test in one of its units. This is the first railway traction test with LNG in Europe and the first in the rail passenger sector in powers below 400hp. The project is developed through an agreement with ARMF (railway integrator), Bureau Veritas and Institut Cerdà.