Biofuels

Introduction

The burning of petrol produces an increment in the emision of greenhouse effect causing gases, which influence the climate of the planet. Petrol, which is a limited resource, takes millions of years to be generated, and at the current rate of consumption could end up totally disappearing. These are two reasons why petrol cosumption must be reduced because it cannot be sustained the way it is.

The alternatives should focus on increasing the effectiveness of the different modalities of transport and diversifying the sector's energy demands in this particular case promoting the use of alternative fuels.

Which may make the process of introducing efficient actions in the transport sector more difficult and that is the fact an important factor must be taken into consideration that it is quite complex to give preference to environmental factors over those related to economy, comfort, speed and security, which have a great amount of value when making decisions.

Objective

Biodiesel is a fuel obtained from animal and vegetable fats and oils and renewable prime matter, which can be used in diesel motors.

The quality of biodiesel depends on two important factors.

• The oil it originates from.

• The fabrication process.

Advantages of Biodiesel

ENERGETIC:

• European strategy for sustainable mobility.

• Obtained from renewable prime matter.

• Reduction of the dependency on petrol and diversification of the sources of energy.

ENVIRONMENTAL:

• Contains a minimum amount of Sulfur and, as well as being biodegradable and therefore not polluting soil and subterranean water.

• Reduces the emision of pollution caused by conventional fuel. In public transport this means a significant reduction of pollution, due to the low concentration of CO2 and SO2 in the gas emisions, and the improved conservation of vegetation, monuments and historical buildings which are affected by the gases caused by conventional fuels.

TECHNICAL-OPERATIONAL:

• Transport, storage and handling is easier due to the fact that it is a non-dangerous product which has no risk of explosion.

• Very flexibe since it can be mixed with conventional fuel in almost any proportion.

• Motors do not need to be modified for it's use.

• Improves the capacity of lubrication compared to conventional fuel.

• Exemption from the Hydrocarbon Tax (till 31/12/2012).

EMT Precedents

With the signing of the protocol in may 1996, by the "Ayuntamiento de Valencia", the EMT of Valencia and "Repsol Comercial de Productos Petrolíferos, S.A.", for the development of testing on a float of urban transport buses with lesser polluting fuels used in agricultural products (BIOFUELS), the first large project using sunflower esters for it's aplication in a mobile fleat of urban buses was produced. The development of the testing took place using:

• 160.000 litres of Repsol biodiesel, 70% Superdiesel (112.000 litres) and 30% sunflower ester (48.000 litres).

• The testing took place on 16 buses using different models (Pegaso 6420 y Renault PR-100.2).

• The TELEMAT system which was installed in the San Isidro depot was used to control the supply of fuel. A storage tank for fuel and a biodiesel pump was assigned to biodiesel bus for this matter.

• The testing began on the 23rd of July 1996 and ended on the 22nd of January 1997.

• A total of 311.000 km were covered.

The technical results were acceptable. The buses motors did not need any type of modification and the conclusions were correct when it came to performance, gas emision and durability. The economic result was poor due to the fact that oils originated from vegetation are expensive and therefore the price of the fuel was not competitive.