restructure biofuel and add concept of sustainable

[stap-m]

Description of the issue

From PR #869

The class biofuel is not properly defined anyway, it has currently only a Wikipedia-based definition. We probably need here two subclasses of biofuel, something like sustainable biofuel and non-sustainable biofuel. Only sustainable biofuel would be renewable as e.g. wood from clearcutting of rain forests which I would call non-sustainable biofuel has at least in my interpretation not a renewable origin.

In the PR, To finish this PR, the axiom 'has disposition' some 'renewable energy carrier disposition' has been added to biofuel. When working on #872, this should be reviewed.

Ideas of solution

Workflow checklist

• [ ] I discussed the issue with someone else than me before working on a solution
• [ ] I already read the latest version of the workflow for this repository
• [ ] The goal of this ontology is clear to me

I am aware that

• [ ] every entry in the ontology should have a definition
• [ ] classes should arise from concepts rather than from words

[l-emele]

As a start, Wikipedia describes sustainable biofuel as: Sustainable biofuel is biofuel produced in a sustainable manner. It is not based on petroleum or other fossil fuels. It includes not using plants that are used for food stuff to produce the fuel thus disrupting the worlds food supply.

So this brings also in the aspect of the food-energy nexus of biofuels. This is not what I had in mind in PR #872, but maybe could/should be a third subclass of biofuel.

[stap-m]

This should probably be solved together with #811.

[l-emele]

This should probably be solved together with #811.

Partially, but biofuel has also some non-liquid subclasses.

[l-emele]

In my view, biogas should be redefined: A biogas is a biofuel portion of matter which has a gaseous state and is composed principally of methane and carbon dioxide produced by anaerobic digestion of biomass. It is used as a biofuel. Additionally it should get the axiom ('has part' some methane) and ('has part' some 'carbon dioxide').

[l-emele]

The class wood and other is currently defined as: Wood and other is solid biomass of purpose-grown energy crops (poplar, willow etc.), a multitude of woody materials generated by an industrial process (wood/paper industry in particular) or provided directly by forestry and agriculture (firewood, wood chips, wood pellets, bark, sawdust, shavings, chips, black liquor etc.) as well as wastes such as straw, rice husks, nut shells, poultry litter, crushed grape dregs etc. Combustion is the preferred technology for these solid wastes. The quantity of fuel used should be reported on a net calorific value basis.

This problematic in two ways:

1. The and other part is rather unspecific.
2. The definition is bloated and conveys much more than one concept.

[l-emele]

Probably it is best to create separate classes for the different types of solid biofuel/biomass like wood, charcoal etc. Also we might define a general biomass class. Some proposals:

• Biomass is a portion of matter from plants or animals and has thus has a biogen origin.
• Wood is a biomass from trees. It has a solid state of matter an can be used as fuel.
• Charcoal is a biomass produced from wood via pyrolysis. It has a solid state of matter an can be used as fuel.
• Biogas is a biomass produced by anaerobic digestion. It is a gas mixture consisting mainly of methane and carbon dioxide. It has a gaseous state of matter an can be used as fuel.
• Biomethane is a biomass produced from biogas by removing carbon dioxide. It is a gas mixture consisting mainly of methane. It has a gaseous state of matter an can be used as fuel.

We might consider defining the processes involved (pyrolysis, anaerobic digestion), too, but I think we should not overload this issue and do it probably in a separate issue.

The liquids are currently defined as and should be updated too (related to #811):

• Biodiesel is a portion of matter that includes bio-diesel (a methyl-ester produced from vegetable or animal oil, of diesel quality), biodimethylether (dimethylether produced from biomass), Fischer-Tropsch (Fischer-Tropsch produced from biomass), cold extracted bio-oil (oil produced from oil seed through mechanical processing only) and all other liquid biofuels which are added to, blended with or used straight as transport diesel.
• Biogasoline is a portion of matter that includes bioethanol (ethanol produced from biomass and/or the biodegradable fraction of waste), biomethanol (methanol produced from biomass and/or the biodegradable fraction of waste), bioETBE (ethyl-tertio-butyl-ether produced on the basis of bioethanol; the percentage by volume of bioETBE that is calculated as biofuel is 47 %) and bioMTBE (methyl-tertio-butyl-ether produced on the basis of biomethanol: the percentage by volume of bioMTBE that is calculated as biofuel is 36 %)

[l-emele]

Current asserted structure of biofuel:

Current inferred structure of biofuel:

[l-emele]

Biofuel in itself has currently a not very useful definition:

A biofuel is a fuel that is produced through contemporary biological processes, such as agriculture and anaerobic digestion, rather than a fuel produced by geological processes such as those involved in the formation of fossil fuels, such as coal and petroleum, from prehistoric biological matter. Biofuels can be derived directly from plants (i.e. energy crops), or indirectly from agricultural, commercial, domestic, and/or industrial wastes.[1] Renewable biofuels generally involve contemporary carbon fixation, such as those that occur in plants or microalgae through the process of photosynthesis. Other renewable biofuels are made through the use or conversion of biomass (referring to recently living organisms, most often referring to plants or plant-derived materials). This biomass can be converted to convenient energy-containing substances in three different ways: thermal conversion, chemical conversion, and biochemical conversion. This biomass conversion can result in fuel in solid, liquid, or gas form. This new biomass can also be used directly for biofuels.

First, this definition is way to long. Secondly this definition describes not only biofuel itself but also a lot of processes involved.

What about describing biofuel simply in its relation to biomass?

• Biofuel is biomass that has a fuel role.
• Biomass is a portion of matter from plants or animals and has thus has a biogen origin. (Repeating my proposal from above).

[stap-m]

Looks great to me, thanks @l-emele .

[l-emele]

Okay, then I'll implement

[l-emele]

I am thinking about the right equivalent to axiom for biofuel.

• biofuel equivalentTo biomass and ('has role' some 'fuel role') would fit to the definition above: A biofuel is biomass that has a fuel role.
• biofuel equivalentTo 'combustion fuel' and ('has origin' some biogenic) would better fit the general structure we have for the fuels. This would imply a different definition: A biofuel is a combustion fuel that has a biogenic origin.

We could make biofuel equivalent to both statements, but that would violate the single inheritance principle.

[l-emele]

@stap-m : Any thoughts on my last comment?

[stap-m]

A biofuel is biomass that has a fuel role.

Uahh, I guess we oversaw that the current definition is wrong anyway! E.g. biogas is obviously not a biomass... 👀 Which makes the decision easy...

[l-emele]

Sorry, I don't understand what you mean with biogas is obviously not a biomass? Is it in your view not a biomass because it is processed?

[stap-m]

Yes. It is made from biomass, but it is not biomass anymore.

[l-emele]

Okay, then I understand. Then charcoal isn't a biomass either. So new proposals:

• Charcoal is a portion of matter produced from wood via pyrolysis.
• Biogas is a portion of matter produced by anaerobic digestion. It is a gas mixture consisting mainly of methane and carbon dioxide. It has a gaseous state of matter an can be used as fuel.

[stap-m]

Add "... has a solid state of matter and can be used as a fuel" to charcoal, too?!

[l-emele]

Yes, I will do that.

[l-emele]

Although pull request #952 was merged, this issue is only partly resolved. The discussion went a bit away from the original idea of this issue. Which was to distinguish between sustainable biofuel and non-sustainable biofuel and that probably only the first one should get 'has disposition' some 'renewable energy carrier disposition'. This has not yet been addressed here. Therefore, I'll reopen the issue and move to milestone 1.9.0.

Also in the PR, I mentioned biodiesel and biogasoline/bioethanol, but I better open a separate issue for these.

[KaiSchnepf]

We could make biofuel equivalent to both statements, but that would violate the single inheritance principle.

I do not get the point why we are violating this principle. I thought, the 'equivalent to' does only affect the inferred view... Right now biofuel is implemented twice in the inferred view, is it because of the 'equivalent to'?.

[l-emele]

We could make biofuel equivalent to both statements, but that would violate the single inheritance principle.

I do not get the point why we are violating this principle. I thought, the 'equivalent to' does only affect the inferred view...

It appear both as biomass and combustion fuel.

Right now biofuel is implemented twice in the inferred view, is it because of the 'equivalent to'?.

That was just now fixed by PR #965.

[KaiSchnepf]

Although pull request #952 was merged, this issue is only partly resolved. The discussion went a bit away from the original idea of this issue. Which was to distinguish between sustainable biofuel and non-sustainable biofuel and that probably only the first one should get 'has disposition' some 'renewable energy carrier disposition'. This has not yet been addressed here. Therefore, I'll reopen the issue and move to milestone 1.9.0.

What about: Add sustainable biofuel and non-sustainable biofuel as subclasses of biofuel and add:

• 'has disposition' some 'renewable energy carrier disposition' for sustainable biofuel
• 'has disposition' some 'conventional energy carrier disposition' for non-sustainable biofuel

definitions:

• A sustainable biofuel is a biofuel that has a renewable energy carrier disposition.
• A non-sustainable biofuel is a biofuel that has a conventional energy carrier disposition.

axioms:

• add the associated 'Equivalent To' axioms

Delete biofuel´s axiom: 'has disposition' some 'renewable energy carrier disposition'

I am not sure about the origin for all three terms and gasous biofuel, liquid biofuel and solid biofuel.

[l-emele]

Thanks for the proposal. They are already quite good, however to me they are missing the link to the sustainable versus non-sustainable production. I think

sustainable biomass production -> sustainable biomass -> sustainable biofuel

non-sustainable biomass production -> non-sustainable biomass -> sustainable biofuel

@stap-m @han-f: Do you have any ideas?

[l-emele]

I just saw, that we have a class primary energy carrier harvest: Primary energy carrier harvest is a primary energy production that collects solid biomass from its natural site. Maybe the concepts sustainable biomass production and non-sustainable biomass production can be derived from that.

[stap-m]

we have origin renewable only for energies. We could add a similar / equivalent origin sustainable for portion of matter?!

Would it make sense to add "attributes" like "sustainable" to processes as well? That might require some more thinking though...

[l-emele]

Introducing something like a sustainable origin is a good idea. The origins biogenic, renewable, and sustainable are connected. Something like if a portion of matter is biogenic and sustainable then it is renewable. (I am here intentionally neglecting that renewable is currently only applicable to energies.)

While talking about origins, our current definition of origin (Origin is a quality that indicates where a portion of matter or energy comes from (its source).) misses one important aspect, that is not yet covered: If something is processed, the origin transfers from the input to the output. Some examples to illustrate what I mean:

• If you take crude oil which definitely has has a fossil origin and refine it to diesel and gasoline, these inherit the fossil origin quality.
• If you take biomass which has a biogenic origin and convert it to biogas, the biogas inherits the the biogenic origin.
• If you take coal which has a fossil origin and use that coal in a coal power plant to generate electrical energy, the electrical energy inherits the fossil origin quality.
• If you take wind energy which has renewable origin and convert it to electrical energy using a wind turbine, the electrical energy inherits the renewable origin.

This is aspect is currently not reflected in our definition. I am unsure whether we should discuss this here or in a separate issue.

[KaiSchnepf]

With the implementation of #976 we did not change the definitions of the subclasses of origin. In my opinion, all subclasses of origin should start their definition with: xxx is an origin of portions of matter or energies ... anthropogenic is already using it.

Would it make sense to add "attributes" like "sustainable" to processes as well? That might require some more thinking though...

In my understanding, if the portion of matter or energy inherits the origin from its primary sources, a process also has to inherit it. Otherwise, the process would "loose" the origin.

Introducing something like a sustainable origin is a good idea. The origins biogenic, renewable, and sustainable are connected. Something like if a portion of matter is biogenic and sustainable then it is renewable. (I am here intentionally neglecting that renewable is currently only applicable to energies.)

Should we start with implementing sustainable first (and non-sustainable)? Currently, we have only implemented sustainable stock potential and sustainable flow potential. After implementing sustainable, we should add 'has origin' some sustainable for both terms. First proposal for a definition of sustainable: Sustainable is an origin of portions of matter or energies made by or produced from life forms and that replenish on a human time scale.

[l-emele]

In my opinion, all subclasses of origin should start their definition with: xxx is an origin of portions of matter or energies ... anthropogenic is already using it.

Not all subclasses can start with this, as some origins are intentionally limited, e.g. renewable is intentionally limited to energies. We have to discuss them case by case.

sustainable stock potential and sustainable flow potential are neither energies nor portion of matters but quantity values so they should not get an origin.

[KaiSchnepf]

Not all subclasses can start with this, as some origins are intentionally limited, e.g. renewable is intentionally limited to energies. We have to discuss them case by case.

I do not understand, why we want to limit it, especially if an output term inherits the annotations from its input terms, as we agreed on in #974 . But this should not stop the discussion.

This table shows the current situation in oeo:

origin	current Definition	currently used for portion of matter	currently used for energy
biogenic	biogenic is an origin of portions of matter made by or produced from life forms.	yes	no
conventional	Conventional is an origin of energies that don't replenish when transformed / consumed.	no	yes
geogenic	geogenic is an origin of portions of matter that are the result of geological processes.	yes	fossil is subclass, so geogenic has to change if fossil is changed
fossil	fossil is an origin of portions of matter created from organic material by geolocial processes lasting thousands or millions of years. In real world, fossils are from biogenic origin some thousands or millions of years ago. However, this is irrelevant in the energy modelling domain. Fossil is a subclass of geogenic which is not covered in this definition btw.	yes	fossil energy
renewable	Renewable is an origin of energies that replenish on a human time scale.	renewable (industrial/municipal) waste fuel	yes
synthetic	synthetic is an origin of portions of matter created artifically by a chemical process.	yes	no

From my point of view, we should especially discuss the three terms with the words in bold. Terms in oeo are using the origins which is not allowed due to the current definition of them.

Additionally, what is the reason for the 'disjoint with' for renewable and fossil? Currently, renewable is an origin of energies and fossil is an origin of portions of matter. I would suggest that conventional should get the 'disjoint with' from fossil. If we change the definition of fossil, the 'alternative term' of conventional non-renewable would still not make sense.

[l-emele]

I think, we should discuss this at an OEO dev meeting.