Fuels (2019 VCE)

 

1) Climate change has been identified as a threat to the environment. Fossil fuels are recognised as a significant contributor to the rise in carbon dioxide levels in the atmosphere. The replacement of fossil fuels as an energy source represents a challenge and has been the focus of research for a number of years. However, there are different opinions/views about the suitability of using a biofuel, such as biodiesel, as a replacement for fossil fuels. Some extracts representing different viewpoints are shown in the box below.

a. Using the chemistry that you studied this year and the information above, discuss the carbon neutrality and the sustainability of using biodiesel as a fuel for transport.

Solution

b. Hazelnuts are a tree crop that has been grown for many years in Mediterranean environments as a tree nut for food. They have been investigated as a potential sustainable and high-yielding feedstock for biodiesel. The species is well-adapted to less productive soil and produces a high amount of very good quality oil. In addition to oil yield, hazelnut oil has a unique fatty acid composition (high monounsaturated fatty acids, predominantly oleic acid).
Reference: Thomas Molnar, ‘Growing hazelnuts for biofuel production’, extension, 31 January 2014,
Petrodiesel produced from crude oil is mainly characterised as C12H24. Compare biodiesel produced from hazelnut oil to petrodiesel in terms of:
• chemical structure
• energy content per kilogram
• flow through fuel lines.
In your answer, you should indicate how these differences have an impact on the selection of biodiesel as a transport fuel.

Solution