▶ Your Answer :
Coal is a useful
material but it causes pollution. According to the reading, several methods are
being developed to make coals an environmentally friendly energy source.
However, the lecturer contrasts the reading passage by talking about drawbacks
of these methods.
First, the
lecturer disagrees with the idea in the reading passage that gasification can
solve the problem of using coal as an energy source. In the reading, the writer
said that they can turn coal into syngas which can remove all the pollutants
from coal. But the lecturer says that to remove those pollutants, coal need to
be heated. This process includes burning fossil fuel so it still causes air
pollution.
The next
argument made by the lecturer is that the use of static electricity isn’t effective.
In this method mentioned in the reading passage, static electricity extracts
pollutants in the air. This helps reducing air pollution. But still it cannot
reduce the emission of carbon dioxide which is the main cause of global
warming. Compared with the emission of ash, the emission of carbon dioxide is
much bigger problem. Therefore, only removing ash particles in the air cannot
solve the problem.
Finally, the
lecturer contends that fabric filter is too expensive to utilize. In the
reading passage, this filter can remove most of dust particles in the air. But
the fact is that the filter need to be changed so its cost gets more expensive.
Also, to use this filter, fans need to be utilized so it consumes additional
electricity reducing the effectiveness of production.
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