add Biomethanation

[BertoGBG]

Closes # (if applicable).

Changes proposed in this Pull Request

added biomethantion technology (biological methantion of CO2 with electrolytic H2). The technology is part of the DEA catalogue and it was added via compile_cost_assumptions.py

Checklist

• [ Y] Code changes are sufficiently documented; i.e. new functions contain docstrings and further explanations may be given in doc.
• [ Y] Data source for new technologies is clearly stated.
• Newly introduced dependencies are added to environment.yaml (if applicable).
• A note for the release notes doc/release_notes.rst of the upcoming release is included.
• [Y ] I consent to the release of this PR's code under the GPLv3 license.

[fneum]

Can we make the renames more consistent with the most commonly used names?

hydrogen-input
co2-input
electricity-input etc.

[BertoGBG]

I have updated the names to the most commonly used names (eg. methane-output insect of Methane Output).
for the final DF and csv file.
Note that the index names set in biomethanation_dea (like "El-Input", "H-Output") (the lines you mentioned) are only used as search keys by str.contains() in the filtering at lines 2155–2204 and 2312–2340. They never appear in the final CSV.

[martavp]

I was trying to double-check the saved values for biochar but the output files are removed in this PR, please, add them again @BertoGBG

[BertoGBG]

the cost files were added

[BertoGBG]

@martavp this PR is only for the biomethanation technolgies, not biochar. They are alternative technolgies to Sabatier reaction and can substitute the biogas upgrading converting the CO2 in the biogas (and H2) to Methane through a biological process. It does not require CO2 removal and the CO2 in the biogas is retained in the system without the need for CO2 netowrk.

[euronion]

Hej @BertoGBG , is this PR ready for another round of review?