Forum for ecoinvent Version 3

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Written on 24.06.2019 by yannegoossens see context

Dear Avraam Symeonidis

Thank you for your answer. I'd like to expand my question a bit.

How do I model the application of compost if I know the composition of it? For example, if the compostion of the compost is: %N: 8.5; P2O: 3.7; K2O:6.4. Is it then enough to just take, for 1 kg of compost application, 0.085 kg of the nitrogen fertiliser, 0.037 of the phosphate fertiliser and 0.064 of the potassium fertiliser. Is that the right way to include 1 kg of compost application in my LCA? Can I completely disregard the information in the documentation regarding: "This application provides the nutrients N, P2O5 and K2O contained in the compost, namely 0.7% nitrogen, 0.4% P2O5 and 0.6% K2O" and the input from technosphere of "Compost {GLO}| market for | APOS, U" for the nutrient supply of respectively 87.5 kg, 44.6 kg en 34.8 kg?

Thanks in advance

Kind regards

 

Written on 24.06.2019 by Florentine Brunner see context

 

Dear Chris,

The amount of steel input to the lost-wax casting process suggests very high losses indeed, which is reasoned with the explanation that the process represents casting of small parts for highly specialized applications, such as aerospace equipment. In this context such high losses were reported by industry.

Hence, you may wish to modify the dataset according to the context of your system.

 

Kind regards,

Florentine Brunner Data Analyst, ecoinvent

 

Written on 21.06.2019 by chrisf see context

The process "casting, aluminium, lost-wax" "represents the service of casting of aluminium parts using this method. In common with other sevice processes in ecoinvent, the input of Al is, I believe, only equivalent to the expected wastage from the process, so that the user scales the process to the mass ofthe piece being cast, and adds the required mass of metal. The implied wastage rate is c.35%, with the waste Al also present as an output of scrap.

In the equivalent steel process ("casting, steel, lost-wax"), there is an input of 18/8 stainless of 1.89kg per kg of casting. This amount of generic scrap steel is present as a waste treatment outflow. What does the Cr steel input represent? Is it really the case that for any kg of steel part cast by this technique a wastage rate of 189% is anticipated? Does it, unlike the Al analogue, include the mass of the piece being cast? If the dataset is used for casting of non-stainless steels, should a different steel composition be used in place of the Cr steel now present? The metadata notes that the technique is normally used for fine parts, but there is a shortage of alternatives, thus some further explanation would be appreciated.

Thanks in advance,

Chrs Foster

Written on 21.06.2019 by chrisf see context

In an LCA of wooden packs, I investigate the land use category. Counter-intuitively, I find land used for roads to be much more significant than land use for forestry, applying ReCiPe 2016 which seems to taek account only of land transformation. of course we are accustomed to counter-intuitive results in LCA. But on checking the quantity of road in the road transport datasets, I find that 0.001m.a input of road construction per t.km for a 16-32 t truck (see, for example, the process "transport, freight, lorry 16-32 metric ton, EURO6" in the cut-off version of ecoinvent 3.5). This seems high: it implies (I think) that for each 10t of goods moved 100km, 1m of road is built each year, albeit not all new road. Certainly roadworks are a ubiquitous feature of the European landscape in the anthropocene era, but they are not all actual (re-)construction. Can anyone comment on the robustness of the underlying data or the validity of this particular flow value?

thanks in advance,

Chris Foster

EuGeos Limited

Written on 21.06.2019 by Avraam.Symeonidis see context

Dear yannegoossens,

 

Thank you for your thread.  All three datasets you refer to, represent three diffrent linked versions of the same unlinked dataset. This is essential the reason you observe identical documentation among them.

On the practical side now, what you use depends on what you you want to model. In your case now that you want to model the application of compost, you need to use all three datasets you refer to. You can divide the amount of 5 kg with the three amounts you mention (87.5 kg, 44.6 kg en 34.8 kg). This will yield the amounts of reference products you need to use from each of the datasets.

How you do it exactly is another situation and depends on the way you use the database. Certain softwares allow the creation of processes where you can add the variable amounts of three other processes for instance.

 

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent

Written on 14.06.2019 by yannegoossens see context

Dear, 

I have a question regarding the "nutrient supply" input processes of the Fertilisers category. For each type of fertiliser (e.g. calcium nitrate, compost, manure, etc.), three possible processes (with different reference products) are provided. For example for compost you have:

  • "Nitrogen fertiliser, as N {GLO}| nutrient supply from compost | APOS, U"
  • "Phosphate fertiliser, as P2O5 {GLO}| nutrient supply from compost | APOS, U"
  • "Potassium fertiliser, as K2O {GLO}| nutrient supply from compost | APOS, U".

All three input processes have the same general comment: "This inventory describes the application of compost for fertiliser use. This application provides the nutrients N, P2O5 and K2O contained in the compost, namely 0.7% nitrogen, 0.4% P2O5 and 0.6% K2O. No emissions are considered. This dataset needs to be revised to include the corresponding process emissions".

The same starting activities: "Activity starting with the application of compost." and the same ending activities: "Activity ends with the provision of N-fertiliser, P-fertiliser and K-fertiliser."

The input from technosphere in the processes do however differ in quantity. For  "Compost {GLO}| market for | APOS, U", you have respectively 87.5 kg, 44.6 kg en 34.8 kg. 

I am wondering how I should use these input processes for including for example the use of 5 kg compost as a fertiliser in my LCA. Is it sufficient to use one of the three possibilities, and which one should I then use? Or should I make a new input process, in which I combine the three different processes and assign percentages to each related to the reference product?

Kind regards

Written on 06.06.2019 by Avraam.Symeonidis see context

Hi, 

Thank you for your thread. Have you had a look in the documentation quoted in this file you mention? There is a certain methodology related to the heavy metal emissions but it is in German. If you are interested send me a private email at: symeonidis@ecoinvent.org and I can send you the pdf in German, if that would be of any help for you.

Best regards,

Avraam Symeonidis,

Data analyst, ecoinvent

Written on 05.06.2019 by sebefruz see context

Hi, 

I have struggled to understand how pesticides are accounted in the calculation of heavy metal emissions for any crop cultivation process in ecoinvent v3. I am aware of the methodololgy provided in "Methods of assessment of direct field emissions for LCIs of egriculture production systems"by Nemecek&Schnetzer (2011), and table has already provided as regards to the heavy metal content of products and fertilisers. But I would like to know also values assumed in Ecoinvent for pesticides depending on type so that I can customise it more appropriately. 

Thank you very much and best regards,

 

 

 

Written on 04.06.2019 by david.turner see context

Response from ecoinvent, June 4th, 2019:

 

In the context of the system model, “Allocation, cut-off by classification”, an exchange may be classified as being either an “ordinary by-product”, a “waste” or a “recyclable material” (for information on how these different classes are handled in the cut-off system model, please refer to the ecoinvent website). Exchange classification is first recommended by the data provider based on expert judgement and then confirmed following review by one or multiple external “expert” reviewers and the ecoinvent team (as well as, in certain cases, the ecoinvent LCI expert group). The classification is then applied consistently throughout the database to all instances of that exchange. Exchange classification is subjective but unfixed; classification may be changed from one release to another if it is deemed appropriate to do.

 

Taking the example of electricity generation from municipal waste incineration in Switzerland, electricity, from municipal waste incineration to generic market for electricity, medium voltage [CH] is supplied (via a market activity) with electricity from 42 activities, each of which representing the “treatment” (incineration) of a specific by-product, e.g. treatment of waste building wood, chrome preserved, municipal incineration with fly ash extraction [CH]. Of those supplying activities, 39 are for the incineration of by-products that have been classified as “waste”. In these cases, the burdens of the incineration activity are allocated to the upstream waste producer, with the generated electricity provided to downstream users burden-free. However, three of the supplying activities are for the incineration of by-products that have been classified as “recyclable materials”: digester sludge, waste newspaper, and waste packaging paper. In these cases, and in-keeping with the convention for handling “recyclable materials” in the Cut-off system model, the activity of incinerating these materials is essentially considered as “recycling”, rather than waste disposal, and the burdens of this “recycling” activity are allocated to the downstream user of the secondary product (electricity, in this case. The figure below illustrates the points of cut-off for treating “wastes” and “recycling materials” in the cut-off system model. Note how, in the case of the electricity, from municipal waste incineration to generic market for electricity, medium voltage [CH], the market is being supplied with electricity from both sources.

 

 Non-zero LCIA scores for electricity from incineration using the cut-off system model2

Download the figure here

 

If the market were supplied exclusively with electricity from incineration activities that treated “waste”, then the burdens of this market activity would, indeed, be zero. However, as the market for electricity, for reuse in municipal waste incineration only [CH] is being supplied by a mix of incineration activities treating “recyclable materials” and “wastes”, it follows that the burdens of this market are not zero. This is a direct consequence of the by-product classification procedure and the fact that each exchange can only be given one classification, which must be applied consistently throughout the database. So why were these three by-product exchanges (digester sludge, waste newspaper, and waste packaging paper) classified as “recyclable materials” rather than “wastes”? Because in the “real world” (in this case, the Swiss MSW system) these materials are far more commonly recycled than they are incinerated at their End of Life; as reflected by their fates in the ecoinvent database.

 

Written on 04.06.2019 by david.turner see context

Question from Gabor Doka, June 1st, 2019 via the Pré LCA Discussion List:

 

When I look at the energy products from incineration (e.g. electricity, from municipal waste incineration to generic market for electricity, medium voltage // CH), *all* of them have some non-zero attributed burden (here exemplified with GWP results)

 

electricity, from municipal waste incineration to generic market for electricity, medium voltage // CH:

kg CO2-Eq/kWh


Allocation, cut-off

0.004183

Consequential

0.1831

Allocation, APOS

0.2631


Even if in the cut-off model the actual burden is very small, it should imho correctly be zero. That burden is not from a distribution grid or similar: already the energy straight from incineration ("market for electricity, for reuse in municipal waste incineration only") has the same burden of 0.004183 kg CO2-Eq/kWh. So some burden from incineration was allocated to the produced energy, which should *not* happen in the cut-off system model.

I don't have an explanation how this non-zero result in the cut-off Model comes about. It is incompatible with the precepts of the cut-off system model. Can anyone help?

Written on 31.05.2019 by Florentine Brunner see context

Dear Julija,

I am not sure I understand what you are referring to with heat pumps from wind for heating. Is that air heat pumps? Or you want a(ny) heat pump regardless of the heat source to use wind power as the electricity input? In the latter case you can modify the heat production datasets by replacing the input of electricity supplied from the electricity market by electricity from wind.

Kind regards,

Florentine Brunner, Data Analyst, ecoinvent

Written on 31.05.2019 by Florentine Brunner see context

Dear Julija,

in the case of household electricity consumption, I would generally advise using low voltage electricity rather than medium voltage, unless otherwise specified 

 

If you are looking for the national electricity mixes, you  can find those for all three voltage levels (high, medium, low) and all geographies readily available in ecoinvent, e.g. market for electricity, low voltage in France. If you look at the undefined (gate-to-gate) version of the dataset you can see how the modeling of the supply chain (high voltage – transformation – medium voltage – transformation – low voltage) is done in ecoinvent. If you would like to model your own electricity mix, you can follow the same structure:

The high voltage mix (the 1kWh you mention) feeds into “electricity voltage transformation from high to medium voltage”. This, in turn, feeds into the medium voltage market. Consider losses for transformation and transmission. Possibly some electricity production technologies produce at medium voltage level and hence feed into this market, while there is also some consumers (commonly large industry) consuming at medium voltage level. After considering all this your medium voltage mix can then feed into “electricity voltage transformation from medium to low voltage” which in turn feeds the “market for electricity, low voltage”. Again consider losses for transformation and transmission/distribution, as well as technologies (such as photovoltaic) which feed into the low voltage level and supply the household consumer.

I hope this helps.

Kind regards,

Florentine Brunner, Data Analyst, ecoinvent

Written on 27.05.2019 by luciavalsasina see context

Dear Jacob, 

 

See the description of "Handling of Waste Products" in the description of the Cut-off system model. In particular: "Any non-waste by-products of a waste treatment (i.e. not other waste products) are cut off and do not give a credit to the producing activity. The point of cut-off is therefore the end of the waste treatment. This also means that the resulting products are available in the database and can be used as burden-free inputs in other activities." This modelling is specific to the Cut-off system model. 

 

Best regards,

Lucia Valsasina, Junior Project Manager, ecoinvent

Written on 27.05.2019 by JacobM see context

Hello, 

I have a hard time to wrap my head around the "treatment of biowaste for anaerobic digestion"-dataset. I'm looking for some kind of climate impact for the production of biogas from biowaste. Is this possible to find from this dataset? If I look at the dataset (allocation, cut of by classification):

"treatment of biowaste by anaerobic digestion"

Reference product: Biogas

Location: CH

LCIA -> IPCC2013

I don't see any climate impact. Is it possible to find this information from any other dataset?

Best regards, Jacob

Written on 27.05.2019 by julija see context

I would like to model future heating scenarios. In the mix it is predicted certain share of geothermal energy used and electrical heat pumps from wind for heating. Which processes should I used to satisfay this? I have found only geothermal for electricity production, and different types of heat pumps, but not the ones using the wind energy which I need.