Question 19M.3.sl.TZ2.b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.sl.TZ2.b |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Evaluate | Question number | b | Adapted from | N/A |
This question is about biofuel.
Evaluate the use of biodiesel in place of diesel from crude oil.
Strength:
Limitation:
[2]
Strength
Any one of:
less flammable «than diesel» [✔]
recycles carbon «lower carbon footprint»
OR
lower greenhouse gas emissions [✔]
easily biodegradable «in case of spill» [✔]
renewable
OR
does not deplete fossil fuel reserves [✔]
economic security/availability in countries without crude oil [✔]
Limitation
Any one of:
more difficult to ignite inside the engine «than diesel» [✔]
more viscous «than diesel» [✔]
lower energy content/specific energy/energy density [✔]
uses food sources
OR
uses land that could be used for food [✔]
«production is» more expensive [✔]
less suitable in low temperatures [✔]
increased NOx emissions for biodiesel [✔]
greenhouse gases still produced [✔]
Note: Accept “«close to» carbon neutral”, “produce less greenhouse gases/CO2”.
Accept “engines have to be modified if biodiesel used” as limitation.
Do not award marks for strength and limitation that are the same topic/concept.
This question was well answered, and many candidates received one or both marks. Some candidate who did not receive marks were too vague, especially with the limitation.
