Bio fuels en

ALTERNATIVE FUELS AND VEHICLES

www.transportlearning.net

BIOFUELS

Carlos Sousa

AGENEAL, Local Energy Management Agency of

Almada



SUMMARY

1. Definition of Biofuels

2. Types of Biofuels

3. Characteristics of Biofuels



DEFINITION OF BIOFUELS

Biofuels are liquid fuels, which are made from a variety of sources of biomass:

• plant materials

• types of crops

• recycled or waste vegetable oils

Biofuels can be used in internal combustion engines, as a replacement or complement of petrol and diesel.



BIOFUELS

Reasons for promoting biofuels are:

• To contribute to the security of energy supply;

• To contribute to the reduction of greenhouse gas emissions;

• To promote a greater use of renewable energy;

• To diversify agricultural economies into new markets.



TYPES OF BIOFUELS

The two main biofuels are:

1. Bioethanol, as a substitute or additive for petrol;

2. Biodiesel, as a substitute for diesel;



BIODIESEL



BIODIESEL

Biodiesel is a general name for methyl esters from organic feedstock.

Biodiesel can be made from a wide range of vegetable oils:

• rapeseed – the most common one

• sunflower

• palm oil

• soy

• recycled cooking oils

Germany and France are the largest EU producers



USE OF BIODIESEL

• Biodiesel can be used pure or blended.

• Most common blends is 5% biodiesel, 95% diesel

• Blends above 5% may invalidate manufacturers warranty

• Blends above 30% may require modifications in the engine

• rubber seals perishing and injectors blocking



BIODIESEL AND THE ENVIRONMENT

Use of 100% biodiesel would reduce “life-cycle” CO2 emissions by 40 to 50%.

But, this is not common…

…Use of 5% blend reduces CO2 emissions by 2 to 2.5%.

Biodiesel is biodegradable



BIOETHANOL

Bioethanol is a alcohol produced from the fermentation of:

• sugarcane and corn: Brazil and USA

• sugar beet or wheat: Europe, mainly Spain, Poland and France are the main producers

• Technology to produce bioethanol from cellulosic materials (agricultural and wood wastes) and separated domestic wastes is not yet well developed



BIOETHANOL

• A 5% blend of Bioethanol does not require vehicle modifications, nor affects manufacturers warranty.

• Substitute for MTBE in petrol (octane enhancer)

• Flexible Fuelled Vehicles, FFV, can use higher concentrations of bioethanol

• Ford, Volvo and Saab sell FFV (blend of 85% bioethanol and 15% petrol)



USE OF BIOETHANOL

• The energy content of bioethanol is about two-thirds that of petrol

• Consumption is higher (volume)

• Bioethanol is an alcohol – contains oxygen (C2H5OH)

• Need to adjust air/fuel ratio – modern engines do it up to 10% bioethanol blends

• Bioethanol has a higher latent heat of evaporation

• poorer cold start ability in winter. Petrol may need to be used for start

• Bioethanol is an octane enhancer

• Higher compression ratios may be used – More efficiency!!



BIOETHANOL AND THE ENVIRONMENT



BIOETHANOL AND THE ENVIRONMENT

• For 100% bioethanol the reductions are typically 50 to 60% on a “life-cycle” basis compared with conventional fossil fuels.

• 5% blends would bring approximately 2.5 to 3% net reductions.



BIOFUELS – ECONOMIC ASPECTS

• Producing biodiesel from oil seeds costs about twice as much as diesel from crude oil

• Producing bioethanol costs about 2-3 times as much as petrol from crude oil

Thus…

• Duty reductions or exemptions are necessary



Thank you for your attention!