Natural Gas

Introduction

Natural gas is a clean source of energy, which produces little pollution and has a low carbon content. Due to this, in it's combustion a lower amount of carbon dioxide is emitted into the atmosphere,and as a matter of fact, the emision of nitrogen oxide is also below the levels emited by petrol and the level of sulfur dioxide is almost zero. Another reason why natural gas conserves the environment is because it is found in the ground and is formed through the process in which organic materials found between rock layers decompose.This energy which is used in the same state in which it is extracted from the ground has no color, no odor and is not toxic. The usual process once that gas has been extracted consists in storing the gas in depots, delivering the gas by canalization to the station, where by the means of compressors the pressure is increased in order to fill the bus gas depots.

The first time EMT started experimenting with natural gas was in 1997, due to the signing of an agreement with "Gas Natural SDG, S.A." and "Compañía Española de Gas, S.A." with the aim of trying out a bus which would run on natural gas for six months for this reason a gas compressing instalation (GNC) was loaned out.

Gas Natural and the EMT

On the 10th of February 2004, Alfonso Novo the president of the board of directors of the EMT, Marta Torrado the vice-president of the same board and Joan Pujol representing Gas Natural sign a contract in order to provide service for the compressed gas loading station in order to construct the station and supply the urban busses which use this type of energy in EMT's fleet with enough energy.

From the signing of the contract onwards the EMT and Gas Natural worked together in the development and construction of the supply station which is expected to open the same day 15 new busses run by compressed natural gas are incorporated in may of 2004.

The contract specifies that this station will have capacity for 50 vehicles which will be incorporated progressively.

Characteristics

The main features of the new loading (GNC) station to be constructed in the EMT's Central Garage and South Depot, located in San Isidro are:

• Total capacity for 50 gas run buses with a length of 12 meters and a maximum daily consumption rate of 130m3(n)/day.

• The station's model is based on "parked loading", which simplifies the infrastructure of the compression station and reduces waiting time at the loading dock.

• There is a total load of 25 pumps.

The GNC loading station has a very simple and practical way of working. Once the vehicle, has arrived at the bus deposit, has gone through it's cleaning process and has entered the loading station, it will be parked and connected to the pump. Once the loading process is over the vehicle will be disconnected. The burden of the 50 buses is done in two steep of 25 vehicles each one.

The gas compressed to 200 bars is supplied at the station at 1.075 (n) m3/h.

The monitorization of the filling process will be done using computers and through a General Control Panel, with a visualization screen, which will analize data, generate supplies and GNC consumption for the busses run on this ecological fuel.

Integration

Currently, EMT Valencia has expanded its fleet of CNG buses to 75 units, characterized by being low-floor and have a tilt and ramp to provide access to the interior of the disabled. Due to the low noise of their engines, significantly reducing the noise emitted during their service.

Bus fleet of CNG-powered EMT and currently in service:

• 45 units Cityclass Iveco CNG (2004, 2006 and 2007).

• NL Man 243F/GNC 25 units (2006 and 2007).

• 5 units Citelis Iveco CNG (2010).