Linking of unit-processes with database Ecoinvent v.3.6

Question

Hello everyone,

as part of my master thesis, I have to carry out a life-cycle assessment with the ecoinvent database (version 3.6). This is about demolition, transport and sorting processes of reinforced concrete. I have already understood that one connects processes in which the output (quantitative reference) of process 1 must correspond to the input of the subsequent process 2.

1) Does this also apply to existing processes of the ecoinvent database? Can I then simply create a new flow and replace this flow as output (process 1) and insert this flow as input (process 2) into the respective database process and set the quantitative reference  at process 1 (output) to my created flow? Or is data lost?

An example (green = quantitative reference with [unit] of the existing process):

• Process 1: excavation, hydraulic digger (ecoinvent: demolition process with excavator): Input: diesel, oil, digger.., Output: waste mineral oil,..., excavation, hydraulic digger [m3]
• Process 2: transport, freight, lorry >32 metric ton (ecoinvent: transport from concrete demolition to sorting plant): Input: diesel, road.., Output: road wear emission,.., transport freight, lorry >32 metric ton [t*km]
• Process 3: machine operation, diesel, >= 74.57 kW, steady-state (ecoinvent: processing/sorting of log material): Input: diesel, oil, Building machine.., Output: waste mineral oil, ..., machine operation diesel [h]

I want to link these 3 processes. The material of the demolition (crushed concrete) does not change from process 1, to process 2 to process 3. 

Can I now do the following:

 Creation of new product flows (for linking the processes):

1. reinforced waste concrete = New quantitative reference  = Input in following process
2. recycled aggregate = New quantitative reference

And then:

• Process 1: excavation, hydraulic digger (ecoinvent: demolition process with excavator): Input: diesel, oil, digger.., Output: waste mineral oil,..., excavation, hydraulic digger, waste reinforced concrete [m3]
• Process 2: transport, freight, lorry >32 metric ton (ecoinvent: transport from concrete demolition to sorting plant): Input: waste reinforced concrete, diesel, road.., Output: road wear emission,.., transport freight, lorry >32 metric ton,  waste reinforced concrete [t*km]
• Process 3: machine operation, diesel, >= 74.57 kW, steady-state (ecoinvent: processing/sorting of log material): Input: waste reinforced concrete, diesel, oil, building machine.., output: waste mineral oil, ..., machine operation diesel,  recycled aggregate [m3]

 2) Do you need to create new product flows or use existing product flows from the database to link the processes?

3) And do I have to copy the individual processes into a separate folder before I edit them, link them together and merge them into a product system?

I know that the questions are very extensive - but the subject is also very complicated.

Thanks in advance for any response.

King regards,

Max

Comments

Hey Max,

I have got a thesis in which I have to work with OpenLCA regarding "Asphalt Production". I have got three processes as well, just one question, how do we link these processes?

Thank You,
Rini

Answer 1

Hi Max,

nice colour-work - the principle you describe is correct, I would however recommend to copy the processes you modify, since otherwise the modified version is used throughout the database, everywhere the process is used, and the original version is lost. You can use new flows or existing flows. You can also add the connection as default provider. It does not matter in which category the process is "sitting", the ID number of the process is used for identification (as for the flow), but it is often convenient to create an own folder for your foreground model.

Best wishes,

Andreas

Comments

Thank you Andreas for your fast answering and the positiv feedback. I have some other questions:
 
1.    Are there any ecological expenses associated with product flows? Apparently not, if you can create your own product flows as well.

2.    Difference Unit/System Process:
If I create two types of product system from a process XY (for unit and system processes) and compare these two in the modelgraph, the unit productsystem shows all the pre-chains of e.g. fuels and machines (market, production..), but not in the system productsystem. Are these pre-chains included in the content of the system productsystem, but are they only not shown?  

3.    If I change the amount of the output-flow (quantitative  reference) in prefabricated processes of the database,  e.g. in the process  "excavation, hydraulic digger"(from 1m3 to 500m3), how is it then ensured that the  inputs  (e.g. diesel) also increase? Do I have to adjust this manually via parameters or do the  program  itself.

Thanks in advance for any response.

Best wishes,

Max