Brainspace – July 2019

30 brainspacemagazine.com @BrainspaceMag /BrainspaceMagazine

biology

Combustion

What are the

options to

using

biofuels?

Greenhouse gases (GHGs) are gases in the upper atmosphere that have heat-trapping

properties. The problem we are facing today is that too many GHGs are being pumped

into the atmosphere. This, in turn, causes the atmosphere to thicken, making the planet

hotter and our weather more extreme. The United Nations (UN) has identifed six

main greenhouse gases. They are:

carbon

dioxide

methane nitrous

oxide

hydrofluoro-

carbons

perfluoro-

carbons

sulphur

hexafluoride

Fuel combustion in motor vehicles is the primary source of nitrous oxide (N 2 O); burn-

ing fossil fuels is the main source of carbon dioxide (CO 2 ); and one of the main sourc-

es of methane (CH 4 ) is the production and transportation of natural gas, oil and coal.

Most scientists believe that one of the major factors contributing to global warming is

the increase in carbon dioxide (CO 2 ) levels in the atmosphere by the burning of fossil

fuels. It’s clear that transportation is a major contributor to greenhouse gases.

Although some vehicles now run on electricity, most run on fossil fuels like gasoline or

diesel, which are burned inside an engine. That’s why it’s called an internal combustion

engine – combustion is a specific term for burning. In a car’s engine, fuel is put into a

small, enclosed space and then ignited. This ignition releases a large amount of energy in

the form of rapidly expanding gases (i.e. an explosion). By setting off hundreds of these

explosions every minute, a car’s engine is able to move pistons up and down, which in

turn is converted into rotational motion by the crankshaft that moves the car. The gases,

which we call exhaust, then leave the engine through the car’s exhaust pipe (tailpipe)

and muffler. These vehicle exhaust emissions can affect air quality (a measure of the

amount of pollutants in the air), both down near the Earth’s surface where we live and

breathe and as high in the atmosphere.

Biofuels are produced from organic material such as plants, municipal waste, agricultural

waste and algae (collectively called biomass). Biofuels are renewable resources that burn

cleaner than gasoline and diesel, and can reduce greenhouse gas (GHG) emissions.

Some biofuels (such as ethanol, biodiesel and biogas) are already being used to reduce

dependence on fossil fuels. Biofuels are not new. Henry Ford originally planned to power

his Model T cars using ethanol, but gasoline became the fuel of choice because it was

cheap, plentiful and could produce more energy per litre.

By understanding the science behind both biofuels and fossil fuels, students can make

informed decisions for their futures.

What is

the leading

cause of

greenhouse

gases and

how does it

affect us?