Author Topic: Issue with transport processes  (Read 4371 times)

Offline NilsK

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Issue with transport processes
« on: July 30, 2013, 11:23 »
Hello,

my aim ist to compare different types of vehicles (electric, petrol, diesel). For that i need to vary the fuel/electricity consumption in the transport processes. My problem is, that i can easily vary the e.g. petrol quantity at the input side of the process, but the emissions on the output side stay the same and I cant figure out which outputs have to be changed, as they are summed up with the ouputs of other inputs like "road" and "passenger car maintenance". There are two parameteres defined in the transport process for the fuel consumption "fc_basis_vehicle" and "fc_constant" but its not clear to me how they work as they are not used in a function. I can change them, but it doesnt have any influence on the input and output quantities. I wonder if there is a possibilty that the emissions of the fuel consumption are automatically calculated depending on the input quantity.

The process i used is: transport, passenger car, small size, petrol, EURO 5 [RER] and i choose the unit process and the allocation system model.

My last solution would be using the operating process of the ecoinvent 2.2 database.

Offline uniquename

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Re: Issue with transport processes
« Reply #1 on: July 31, 2013, 09:07 »
Hi NilsK

if you have a look at the unit process in Umberto NXT LCA you can see that in this process, the non-fuel coefficients are determined by parameters which can be found on the parameters tab. However, on the parameters tab you can find many more parameters (like the fuel consumption), but as you mentioned these are not used on the Input /Output tab and thus, changing them does not influence the results.
These parameters, which are not used for calculation in Umberto NXT LCA have been used by ecoinvent to calculate the coefficients. They are kept in the parameters tab for information but can not be used for adapting the process.
I have downloaded the dataset from the ecoquery page as well to have a look at the process as .xml and also in this file you can't see the formulas which use the remaining parameters.

However, as you chose the unit process, all exchanges are direct exchanges. So exhaust and non-exhaust emissions are summed up for the all the emissions on the output side. I would assume that the majority of the emissions are caused by burning fuel.