2.6 Transport system challenges

Question 1

Comment on the trend for travelling to work and explain why there is a need for a move towards more sustainable forms of transport.

Answer 1

Answer;

Majority of population use private transport (car / van / taxi) {1}.

This uses more fossil fuels and creates more carbon emissions {1}.

Question 2

Question; Outline three of the key challenges that must be met by those developing sustainable ways to transport people and goods in the future {3}.

Answer 2

Answer;
Response to include any three from;

 Economic viability;

 Environmental impacts

 Dependence on fossil fuels.

 User safety.

Question 3

Question;

New vehicle technologies are being developed which aim to reduce global dependency on oil as a fuel.

Name two new vehicle technologies. {2}

Answer 3

Answer;
Any two from;

 Hydrogen fuelled vehicles.

 Biofuelled vehicles.

 Electric vehicles.

 Hybrid vehicles.

Question 4

Question;
Identify one new vehicle technology that has the potential to reduce global dependency on oil as a transportation fuel and describe the infrastructure changes that would be required to allow it to work effectively.

Answer 4

Answer;
Any one from, {1};

 Hydrogen fuelled vehicles.

 Bio-fuelled vehicles.

 Electric vehicles.

Any one from;

 Electric vehicles {1} – need an extensive infrastructure planned and developed what will allow drivers to plug in their vehicles {1}. Purely electric vehicles are totally reliant on their battery pack so they will be confined to short commutes if the network of charging stations isn’t developed. Plug in cities initiative {1}.

 Hydrogen fuelled vehicles {1} – Hydrogen fuelled vehicles will require extensive hydrogen pipeline transporting hydrogen to specially equipped hydrogen filling stations {1}. Due to the physical qualities of hydrogen, health and safety is an issue which must be addressed {1}.

 Bio fuelled vehicles {1} – Greater production of biofuels required which has implications for land use {1}. Adaption required at filling stations to ensure accessibility for motorists {1}.
All relevant, valid responses will be given credit.

Question 5

Describe the process of Biomass Pre-treatment and Cellulose Hydrolysis

Answer 5

Answer;

A: Biomass Pre-treatment: During this phase the biomass is treated with enzymes {1} so that cellulose material will be amenable to hydrolysis {1}.

B: Cellulose Hydrolysis: Any remaining cellulose is hydrolysed into glucose {1}. Cellulase enzymes are used to break the chains of sugars that make up the cellulose, releasing glucose {1}.

Question 6

Question: (II) With the aid of a chemical equation, outline what is meant by Glucose fermentation. {2}

Answer 6

Answer;

The chemical breakdown of glucose to form ethanol:

C6H12O6 = 2C2H5OH + 2CO2

As the sugars are broken down, ethanol and carbon dioxide are produced {1}.

Question 7

Question;
The word equation below illustrates the production of biodiesel from vegetable oil using methanol and sodium hydroxide.

Soybean oil + Methanol + Sodium Hydroxide = Biodiesel + Glycerine

(I) – What is the name given to the type of chemical reaction that occurs between the vegetable oil and the methanol? {1}

(II) – What is the function of the Sodium Hydroxide in the process? {1}

(III) – Name one other type of vegetable oil that might be suitable for conversion into biodiesel.

Answer 7

Answer;

(I) – Transesterification.

(II) – Catalyst 
. 
(III) – Any one from; 
 Palm oil. 
 Used vegetable oil. 
 Corn oil.

Question 8

Explain two advantages of using biodiesel as a substitute fuel for private and commercial vehicles.

Answer 8

Answer;
Any two from;

 Doesn’t require any radical changes to switch to the use of biofuels {1} unlike the difficulties in switching to other renewable energy sources such as solar and wind power {1}

 Are cheaper than fossil fuels {1}. Many governments are now offering tax incentives to buy greener cars that run on biofuels (ethanol being one example) {1}.

 Are considered ‘carbon neutral’ by some people. This is because the carbon dioxide they release when burnt is equal to the amount that the plants absorbed out of the atmosphere {1}. Therefore, they don’t contribute to global warming. However, it does require some fuel to power the machinery on the farms where biofuels are produced. Research suggests that they reduce carbon emissions by 50-60% {1}.

 Reduce dependence on foreign oils {1}. Oil fluctuates in price rapidly, so changing to biofuels will help buffer against the change {1}.

 Emit less particulate pollution than other fuels {1}, especially diesel {1}.

Question 9

Question;

Explain two reasons why the rising global production of biofuels is a contentious issue. {4}

Answer 9

Answer;

Reference should be made to two of the following Biofuel issues;

 Biofuels take a large expanse of area to grow. Land will have to be cleared for more growth. Rainforests and other high biomass lands are cleared on a mass scale for biofuel production (which may happen tin lower income countries) then the amount of green-house gases emitted would be hugely significant. Multiple studies have been found to draw the same conclusion.

 Farmers in developing counties may move land away from food crop production biofuels ‘cash crop’ reducing food supplies and increasing the prices of staple foods.

 Biofuels may raise the price of certain foods which are also used for biofuels such as corn.

 As other plants are replaced, soil erosion will grow.

 A lot of water is used to water the plants, especially in dry climates.

 Deforestation in South America and South Eastern Asia causes loss of habitat for animals and for indigenous people living there.

All relevant, valid responses will be given credit.

For each reason award {1} for a brief explanation and {2} for a full explanation.

Question 10

Question;
Policy makers employ different strategies to reduce transport demand in urban centres. One such strategy is congestion charging which was introduced in London in 2003.
Assess three effects of congestion charging in central London.

Answer 10

Answer;

Any 3 valid points from;

 The use of cars went down by more than a third following the introduction of congestion charging which is evidence that it was effective.

 The use of public transport such as taxis and buses increased following congestion charging which reflects movement away from private to public transport.

 The number of buses increased by more than 50%.

 The number of bicycles in use has more than doubled.

 The overall number of vehicles entering London has gone down since congestion charging was introduced which reflects the success of congestion charging in relieving congestion.

Question 11

Name Fuel crops / produce that are normally grown specifically for energy use.

Answer 11

Maize
Corn 
Wheat crops 
Waste straw 
Willow trees 
Sawdust 
Reed canary grass 
Cord grasses 
Jerusalem artichoke 
Myscanthus 
Sorghum plants

Question 12

Question
(continuation of last question, mentioning congestion charging);

Outline three other strategies that policy makers employ to reduce transport demand. Comment on the effectiveness of each strategy. {6}

Answer 12

Answer;

Any three named strategies and three relevant comments on the effectiveness of each strategy such as;

 Subsidised public transport {1} makes it economically beneficial to use which increases the use of public transport {1}.

 Extending the public transport network {1} decreases journey times, increases capacity and increases the ease of access to the network which increases use {1}.

 Dedicated bus and cycle lanes {1} decreases journey times and thereby increasing the attractiveness of using these mode of transport compared with driving {1}

 Fuel and vehicle taxation {1} increase the cost of driving. This increases the use of public transport, cycling and car which reduces the number of vehicles on the road {1}.

Question 13

Identify the 3 distinct stages for the production of Bioethanol.

Answer 13

Stage 1: Fermentation
Ethanol is produced by the microbial fermentation of sugar. microbial fermenation will curretnly only work directly with sugars. two major components of plants, starch and cellulose, are both made up of sugars, and can in principle be converted to sugars for fermentation. currently, only the sugar (e.g. Sugar cane) and starch (e.g. corn) portions can be economically converted.

Stage 2: Distillation
For ethanol to be of use, the excess water must be removed. most of the water is removed by distillation. however the purity is limited to 95-96% due to the formation of a low boiling water-ethanol azetrope.

Stage 3: Dehydration
To remove the remaining small portion of water.