I will pre drop my source material to you from the Locomotive study.
Locomotives with less Co2 or no Co2 depending on the fuel source they used 10 different biofuels and selected the top three fuels.
google Search (locomotive bi fuel ontario study nh3 fuel)
Locomotive Fuel Study in Ontario
Here is the raw link https://ir.library.dc-uoit.ca/bitstream/10155/431/1/Hogerwaard_Janette.PDF
First article in the list of science articles
PAGE 109 is where they select the top 3 fuels to run in locomotives for a cleaner environment. I can not post the table so skip over the science stuff to the conclusion.

Tuesday, August 6th 2019

Article 1 https://www.ncbi.nlm.nih.gov/m/pubmed/18357622/?fbclid=IwAR0THzxWKowAjTGF9fs_VpzL6DeeEyhsNMZYxPLPQx6NpTx32z5kbnCmjxQ Article 2 https://link.springer.com/article/10.1007/s11434-006-2096-y?fbclid=IwAR3_ln2TvgJJQUuRjXzW6uyAhZJUl4Kc-uidObW3p4ual0Jh-YHRZ903cs8

https://www.youtube.com/watch?v=cM9uSRrdDaY&t=1164s Long video

Biofuels from Algae Project Brunswick College Ultrasound to convert to BioFuel.
Short Video