Waste modelling help please.

Post Reply
jaydagdag.thei
Posts: 11
Joined: 20 Jan 2017 07:25

Waste modelling help please.

Post by jaydagdag.thei » 20 Mar 2017 16:20

Hi OpenLCA forum. Do you have any example or tutorial on how to model waste. For example, I have modeled the production process of a reinforced concrete structure already. As I want to study the whole life cycle of my project, I would like to include the disposal part.

For instance, I want to allocate 42% of steel waste to recycling and the other 58% on waste treatment. At the same time, the 30% of concrete waste is recycled and the remaining 70 % is going to land fill. I cannot find a good documentation on waste modelling from your manual. I want to make sure that I am doing the correct modelling procedure in Open LCA. I am in need of urgent help. Thanks very much in advance.

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Waste modelling help please.

Post by aciroth » 21 Mar 2017 09:38

Hi, that is a good question. So far, you need to model waste treatment as a service; we follow here some existing databases like ecoinvent (and I agree this is not too intuitve at first).
Best wishes,
Andreas

jaydagdag.thei
Posts: 11
Joined: 20 Jan 2017 07:25

Re: Waste modelling help please.

Post by jaydagdag.thei » 21 Mar 2017 14:13

Could you please elaborate more on treat waste as a service? I am using Ecoinvent waste processes as outputs and allocated them physically based on he percentage that I mentioned, but I am unsure of the results of my calculation.

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Waste modelling help please.

Post by aciroth » 22 Mar 2017 08:46

In a nutshell, waste treatment is modeled so that the waste treatment process delivers a service (treatment of waste xy) to the process which is creating the waste, and since the "real" flow should be an output flow (waste is going from the waste production to the waste treatment process) the sign of the waste treatment service (on the input side of the waste production process) is set to negative to maintain the mass balance.
Hope this helps!

jaydagdag.thei
Posts: 11
Joined: 20 Jan 2017 07:25

Re: Waste modelling help please.

Post by jaydagdag.thei » 22 Mar 2017 13:01

Does that mean I have to model all the waste treatment processes in the input along with the source of the waste? And then one output reference flow? How about the allocation method in which I have to separate the wastes by materials from the source?

jaydagdag.thei
Posts: 11
Joined: 20 Jan 2017 07:25

Re: Waste modelling help please.

Post by jaydagdag.thei » 22 Mar 2017 13:04

Please check if I am doing the right modelling
Attachments
1.PNG
1.PNG (110.85 KiB) Viewed 1786 times
2.PNG
2.PNG (82.42 KiB) Viewed 1786 times

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: Waste modelling help please.

Post by aciroth » 23 Mar 2017 09:27

Hi,
Does that mean I have to model all the waste treatment processes in the input
not really - if you check any ecoinvent waste treatment process, there this principle that I tried to describe is already applied. For your own processes, if a process is creating waste, and this waste goes to another process for treatment, the waste treatment process, then you should model it so that the waste treatment process delivers a service (treatment of 1kg waste) to the process where the waste is created, and in this process, the waste treatment service is input. You should change the sign to preserve the mass balance; the process producing waste thus has input of -1kg waste treatment service (for example), which is provided by the waste treatment process.
Hth,
Andreas

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest