Course Assessment: Part 2
The second part of the assignment is based on the LCA example on the automotive “body-in-white” covered in lectures. The main parameters from the Simapro model have been converted into an Excel file, which is available on the Blackboard site.
The basic model in the file includes the following for the steel body in white:
200 kg of hot-rolled steel
200 kg of sheet rolling
3 kg of zinc
203 kg of drawing (manufacture)
Additional materials for the heavier engine (combined together into a single unit)
Fuel use attributed to the weight of the steel BIW
Fuel use attributed to the additional engine weight
For the carbon-fibre composite BIW, the following are included:
43.45 kg of carbon fibre
35.55 kg of epoxy resin
79 kg of moulding
Fuel use attributed to the weight of the composite BIW
Waste treatment of the composite, made up of an incineration process, plus the heat saved from not needing to burn other fuels (assumed to be coal).
For both cases, fuel use is determined per litre of fuel attributed to the BIW weight over the lifetime of the car, which is taken as 200,000 km.
Details of how fuel efficiency varies with weight are given in the case study lecture.
The Excel file has the following sheets:
The process mid-point values of impacts in each category, expressed in different units for each category. For instance climate change is expressed as kg CO2 equivalent.
In addition to the processes used above for the initial model, three extra processes that you could use are included. These are pyrolysis of carbon-fibre composite, electric motor and battery system.
The mid-point values calculated for the steel BIW.
The mid-point values calculated for the composite BIW.
The end-point values, grouped into Human Health, Ecosystem Loss and Resource Depletion for the steel BIW.
The end-point values for the composite BIW.
A set of conversion factors to convert from mid-point values to end-point values.
A set of normalisation values, for an individual’s annual impact in each category. These are done for an average European and for a worldwide average.
You need to perform a quantitative and/or qualitative analysis of any two of the following changes to the basic model.
A pyrolysis process has been developed that can recycle carbon fibre composites. The mid-point values for the process are included. You need to consider how you would change the model to account for the carbon fibres that are recycled out of this process. A quantitative analysis using the Excel file would be expected. If the recycled carbon fibres are not as strong as new fibres, consider how you might include this effect in the model.
With the basic model, calculate normalised values of the mid-point values. Compare these to normalised end-point values and discuss why there may be differences. Use European or Worldwide values, or maybe both.
If a hybrid car was used, there would be a need for a battery system and electric motor. Mid-point values for these are given, but without any information of the weight required or how much fuel a hybrid system would save. Try to find some information on this (at least enough to give reasonable approximations) and use this to do a quantitative assessment of how a hybrid will change the values for one of the vehicles (steel BIW or composite BIW).
The current model uses a typical mix of steel. The hot-rolled steel used in the model is produced with the following processes:
Hot rolling, a process done on all the material regardless of the source of steel.
Electric Arc Furnace steel production, which makes up 35% of the steel and uses entirely scrap as a feed-source.
Basic Oxygen steel production, which makes up the remaining 65% of the steel. This uses 70% pig-iron from a blast furnace, and 30% scrap.
Blast furnace production, which is used to make up the 70% that goes into the Basic Oxygen process. This includes all the downstream impacts of raw materials extraction.
This means that the current model uses steel that has a recycled content of about 55%. Automotive steel will be recycled almost completely, so you need to consider how you would modify the model to treat this more fairly. This will not be a quantitative analysis, but will involve some detailed qualitative analysis after careful thought. There may be more than one way of addressing this and discussion of the different methods would be good. Flow diagrams will be much more useful than rather vague descriptions.
The report for this should be in the form of a word document with accompanying Excel file and graphs. Try to be as concise as possible but clearly explain what you have done in doing the analyses. Also ensure that your Excel file is clearly laid out so that I can easily see how you performed your analyses.
Submit the report electronically via Blackboard by 3pm on 11th January 2016.
Dr Gavin Bunting will be available to answer questions about the assignment up until the 17th December 2015.