Question 22N.2.sl.TZ0.d
| Date | November 2022 | Marks available | [Maximum mark: 2] | Reference code | 22N.2.sl.TZ0.d |
| Level | sl | Paper | 2 | Time zone | TZ0 |
| Command term | Discuss | Question number | d | Adapted from | N/A |
Lignite, a type of coal, contains about 0.40 % sulfur by mass.
Discuss two different ways to reduce the environmental impact of energy production from coal.
[2]
Any two of:
remove sulfur from coal ✔
add lime during combustion ✔
not allow sulfur oxides to be released into the environment ✔
reduce proportion/percentage of energy/power produced by «the combustion of» coal ✔
Accept any valid method to wash coal and remove sulfur content for M1.
Accept any valid combustion/post-combustion method to remove sulfur oxides.
Accept any suggestion that would reduce the amount of coal that is burnt or would reduce the damage caused.
Do not accept answers that only reduce production of SO2/CO2 from other fuels.
Accept “improve efficiency of energy production from coal”.
Accept “use coal of lower sulfur content” OR “cleaner coal”.
Some candidates referred to the pre-combustion and post combustion methods of minimizing the release of SO2. Some candidates focused on using cleaner coal, other fuels or renewable energy sources. Some mentioned increasing the efficiency of power stations to reduce the amount of coal burned. Some focused on removing the CO2 released by planting trees. All these options were valid with sufficient detail. But answers that were not relevant to coal, such as fitting catalytic converters on cars, were not accepted. 15% of the candidates did not answer the question, and the average mark was 0.8 out of 2 marks.
