Solutions To Fuel Problems L.O: To evaluate alternative fuels and solutions to the problems of waste...

Solutions To Fuel Problems

L.O: To evaluate alternative fuels and solutions to the problems of waste gases

Wednesday, April 19, 2023

Pollutant gases

3 of 15 © Boardworks Ltd 2011

Power station emissions

Flue-gas desulfurization (FGD) involves filtering sulfur dioxide and particulates from power station emissions.

The air pollution created by power stations when fossil fuels are burned can be reduced by:

everybody using less electricity to reduce the amount of fossil fuels that need to be burnt

removing sulfur from fuel oil, coal and natural gas

flue-gas desulfurization.


Flue-gas desulfurization

Polluted flue gas stacks can be wet scrubbed with a water and limestone slurry (calcium carbonate), to form calcium sulfate, or gypsum, which is sold for use in construction.

During gas phase oxidation and reaction with ammonia, the sulfur dioxide emitted from coal-burning power stations is oxidized, then the sulfur compounds that are formed are reacted with ammonia to form ammonium sulfate.

Sulfur can be removed from emissions after fossil fuels have been burned with techniques including wet scrubbing and gas phase oxidation and reaction with ammonia.


Reducing pollution


carbon dioxide

carbonmonoxide

oxides of nitrogen

nitrogen

++

Catalytic converters

A catalytic converter is a device that is fitted to the exhaust pipe of a car to clean up exhaust fumes.

The converter uses a metal catalyst, such as platinum or palladium, to change the pollutants from incomplete combustion (carbon monoxide and oxides of nitrogen) into less harmful substances (carbon dioxide and nitrogen).

2CO 2NO 2CO2 N2+ + What is the problem with this solution to harmful gases?


Research alternative fuels such as hydrogen, biodiesel and ethanol.

HINT: The next few slides on this power point may help.

Write an article or create an information leaflet on the alternative fuels. Include the advantages and disadvantages and whether that are economic, ethical, social and environmental considerations.

Homework to finish!


Alternative fuels


Would you use alternative fuels?


What are biofuels?

Biofuels can be safely combined with normal petrol or diesel and used in conventional engines to reduce levels of harmful emissions without causing engine damage.

Biofuels are renewable fuels produced from plant material, such as agricultural crops, or animal oils.

Bioethanol and biodiesel are types of biofuels used in vehicles to reduce the demand for petrol.


Bioethanol

Bioethanol is produced by the natural fermentation of the sugars in certain plants, such as sugar cane or sugar beet.

Flexible Fuel Vehicles (FFVs) are engineered to run on fuel that is a blend of ethanol and petrol. FFVs have long been popular in Brazil, where farmers are paid generous subsidies to grow sugar cane for bioethanol. Cars that can run on bioethanol are also taxed at a lower rate than cars that cannot.


Biodiesel

Biodiesel is produced by chemically reacting vegetable oils or animal fats with alcohol and a catalyst. The process can be completed in 12 hours.

There are few garages in the UK that sell biodiesel. Home-made fuels from vegetable oils are not taxed to encourage people to use them.

Biodiesel can be mixed with conventional diesel, which significantly reduces harmful exhaust emissions (although the fumes from a biodiesel car can smell like fried foods!).


Biofuels vs. fossil fuels


Hydrogen fuel cells

Hydrogen fuel cells are electrochemical energy conversion devices that work by combining hydrogen with oxygen from the air to form water, producing electrical energy in the process.

Methanol, natural gas and propane have all shown potential for use in fuel cells.

Unlike in a battery, where all the chemicals needed for energy conversion are stored inside, the hydrogen needed for a fuel cell to work can be replenished.


Advantages and disadvantages


Using electricity

Vehicles powered by electricity stored in batteries have been used for a number of years.

Currently the batteries can be large and heavy, and many may be needed to power a vehicle. They need to be regularly recharged, which can take a long time.

Provided the electricity used in the battery is generated from a renewable energy source, such as a wind turbine, vehicles powered entirely by electricity produce no harmful emissions.


Developing electric cars

Scientists are working to develop practical, everyday cars that can run on electricity for longer journeys. More people using electric cars than petrol or diesel cars could dramatically decrease a country’s harmful emissions.

However, if a large number of people suddenly converted to using electric cars, the increased demand for electricity could put a strain on the National Grid.

Governments are also encouraging people to switch to electric cars – in the UK, people who drive electric cars are exempt from road tax and car parking charges in many areas.

Environment Versus Economy There are a variety of alternatives to fossil fuels, and one

of the most promising is using hydrogen as a fuel

Hydrogen and oxygen will react together releasing energy – their only by-product being water

The problem at the moment is getting the hydrogen – it can be split from water, but requires energy to do so (currently from burning fossil fuels)!

Biofuels such as biodiesels and ethanol are produced from plant material – however is it right to grow crop for fuel when many of the world’s population remain hungry?

Research

Research the current fuel situation for the entire world, considering the following criteria: - Economical Environmental Social Long term future Reliability Storage and convenience / infrastructure already in

place

Identify the pros and cons of fossil fuels / biofuels / hydrogen fuel and form your own opinion of the way we should go forward…


True or false?


Multiple-choice quiz

Solutions To Fuel Problems L.O: To evaluate alternative fuels and solutions to the problems of waste...

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