Alternative Fuels

Phase 3 Group 6

Introduction

Use of alternative fuel can lessen dependence on oil and reduce greenhouse gas emissions

Number of alternative fuels

Ethanol

Alcohol-based fuel

Made by fermenting and distilling starch crops

Can also be made from plants (e.g. trees, grass)

E10 10% ethanol 90% petrol/gasoline - almost all manufacturers approve use

E85 85% ethanol 15% petrol/gasoline - can be used in FFVs (flexible fuel)

Designed to run on petrol/gasoline, E85 or both - offered by several manufactruers

No noticeable difference in performance when E85 used

FFV’s operating on E85 experience 20-30% drop in MPG due to ethanol lower energy

Ethanol +/-

+ Lower emissions of pollutants

+ More resistance to engine knock

+ Added vehicle cost small

- Only be used in flex-fuel vehicles

- Lower energy content - fewer MPG

- Limited availability

Biodiesel

Form of diesel manufactured from veg oils, animal fats, recycled restaurant oil

Safe, biodegradable, produce less air pollutants

Can be used in pure form (B100) or blended 

Common blends: B2 (2% biodiesel), B5, B20

B2 and 5 can be used in most diesel engines

Manufacturers do not recommend  using blends more than B5

Biodiesel +/-

+ Can be used in most diesel engines

+ Less air pollutants and greenhouse gases

+ Biodegradable

+ Non-toxic

+ Safer to handle

- Use of blends above B5 not yet approved

- Lower fuel economy and power

- More nitrogen oxide emissions

- B100 generally not suitable for use in lower temperatures

- Concerts about B100 impact on engine durability

Natural Gas

Fossil fuel made of mostly methane

One of closest burning alternative fuels

Can be used in form of compressed (CNG) or liquefied (LNG)

Dedicated natural gas vehicles designed to run on natural gas

Dual/bi-fuel vehicles can also run on petrol/gasoline or diesel

Dual fuel vehicles take advantage of wide-spread availability of conventional fuels, but use cleaner, economical alternative when natural gas available

Natural gas stored in high-pressure fuel tanks, dual-fuel vehicles require two seperate fuelling systems, taking extra space

Natural gas vehicles not produced commercially in large numbers

Conventional vehicles can be retrofitted for CNG

Natural Gas +/-

+ 60-90% less smog producing pollutants

+ 30-40% less greenhouse gas emissions

+ Less expensive than petroleum fuels

- Limited vehicle availability

- Less readily available

- Fewer miles on a tank

Propane or Liquid Petroleum

Propane or liquefied petroleum gas is clean-burning fossil fuel

Can be used to power internal combustion engines

LPG-fuelled vehicles produce fewer toxic and smog-forming air pollutants

Petrol/gasoline and diesel vehicles can be retrofitted to run on LPG and conventional fuel

LPG stored in high-pressure fuel tanks

Seperate fuel systems needed in vehicles powered by LPG and conventional fuel

Propane or Liquid Petroleum +/-

+ Fewer toxic and smog-forming air pollutants

+ Less expensive than gasoline

- No new passenger cars or trucks commercially available

- Less readily available than conventional fuels

- Fewer miles on a tank of fuel

Hydrogen

Can be produced from fossil fuels, nuclear power or renewable resources (hydropower)

Fuel cell vehicles powered by pure hydrogen emit no harmful air pollutants

Hydrogen being explored as fuel for passenger vehicles

Can be used in fuel cells to power electric motors or burned in IC engine

Is environmentally friendly fuel that has potential to dramatically reduce dependence on oil

Several challenges must be overcome before can be used

Hydrogen +/-

+ Can be produced from several sources

+ No air pollutants or greenhouse gases used in fuel cells

+ Produces only NOx when burned in

- Expensive to produce

- Only available at few locations

- Fuel cell vehicles currently too expensive

- Hydrogen has lower energy density than conventional petroleum fuel

Summary

All fuel types offer significant advantages commercially, environmentally or both

Also some disadvantages - mostly cost of production high

Likely to change as use becomes more widespread

Case Study - Introduction

Ford Escape Hybrid E85

Combination of two petroleum-saving technologies

Are hybrid electric power and flexible fuel capacity

Combination cam with unique challenges

Case Study - Ethanol

More corrosive than traditional fuel

Escape Hybrid E85 retrofitted with fuel and engine system components of corrosion-resistant materials and adhesives

Ethanol doesn’t posses same energy density or burn rate as petrol/gas, requiring system to deliver more fuel to injectors to keep performance levels comparable

To handle increased fuel flow, Escape Hybrid E85 has larger fuel pump and larger injectors

Case Study - Engine Control

Capable of running on conventional fuel or E85

To achieve this,ECM has to learn what’s in tank and make appropriate adjustments

ECM monitors exhaust gas sensor, air-fuel ratio and quantity of fuel in tank

When sensing change in engine air-fuel ratio to lean side (more air than fuel)

Deduces vehicle filled with E85 and adjusts fuel system accordingly

Case Study - Learning

Vehicle learns while engine running

Engine may shut off for long periods of time while vehicle runs on electric power

Ford had to make custom software and calibration changes within ECM to make sure could remember or relearn correct percentage of ethanol after shutdown

Case Study - Summary

Ford Escape Hybrid E85 provides same smooth ride, performance and handling customers enjoy with conventional fuel/electric Escape Hybrid

Expected this combination may become more popular in near future