I really don't understand the logic of trying to ship liquid hydrogen about, save perhaps at very small scale.

Here is an analysis of shipping costs for liquid hydrogen, LNG, methanol, DME and ammonia:

https://www.sciencedirect.com/science/article/pii/S2352484720312312

Ammonia is the winner, although some others, not liquid hydrogen, are not too bad.

I like LOHCs, and they are certainly easy to transport about, without some of the issues of toxicity of ammonia

However, Hydrogenious show their LOHC at 6.23% hydrogen by weight here:

https://www.angloamericanplatinum.com/~/media/Files/A/Anglo-American-Platinum/presentations-and-speeches/developing-a-hydrogen-infrastructure-in-china.pdf

That compares to 17.65% for hydrogen in ammonia by weight, which makes me suspect that it is way cheaper to ship ammonia about than LOHCs, also.

And there is considerable existing infrastructure for ammonia.

This would allow a train with the PEM to reform LNG

@SJC

Well, at current prices LNG is currently more expensive than green hydrogen in Europe:

https://www.wsj.com/articles/green-hydrogen-is-cheaper-than-lng-in-europe-11658312552

That is not the end of the story, of course, as the hydrogen still has to be liquified and distributed, and in any case the issue with green hydrogen in Europe is we need a massive build up for multiple demands.

But the argument that LNG prices will fall back is weakened by green hydrogen costs being on an ever falling trajectory.

I can't see European train companies as likely to switch their preferred future fuel when the cheapest source of LNG is to liquify Russian gas.

Here is an in-depth article on DME as an energy carrier:

https://www.frontiersin.org/articles/10.3389/fenrg.2021.663331/full#B32

They fancy burning it in conventional engines, which I don't really find too persuasive, but perhaps I am simply becoming a bit overwhelmed by the sheer number of possible pathways forward in this very exciting seminal time for energy technology.

It reminds me a bit of the early days of designing steam engines, when all was wonderful, there were umpteen projects floated, many of them downright weird!

@SJC

Yeah, there are loads of possible pathways, so many that I lose track.

The usual issues with biomass are land use and displacement of food products, but some pathways mitigate that.

On the upside, huge amounts of resources are currently chucked away, often at a high cost to the environment, so for instance a lot of biogas from large scale pigfarms and so on is just another pollutant instead of used for its energy.

Here is NYC a couple of years ago, discussing the issues:

https://www.waste360.com/anaerobic-digestion/biogas-resource-breaking-down-benefits-and-potential-roadblocks

@Gryf:

I'm not sure that Cummins are planning trains before trucks, as they are also putting ICE hydrogen engines into trucks:

https://www.greencarcongress.com/2021/09/20210924-cumminsh2ice.html

' The development of the 6.7-liter hydrogen engine will focus on medium-duty truck, buses, and construction applications, such as excavators and wheel loaders. A new 15-liter platform offers the potential to bring hydrogen gas-fueled engine capability to heavy-duty long-haul trucks. '

They are also developing PEM etc as the article says.

Their answer appears to be so far as is practicable 'All of the above' which in my view is sensible with the present immature state of the technologies, and transition issues, so that in this case retaining a lot of the parts in conventional engines, and enabling retrofitting etc is a plus, likely not a forever solution, but a bridge.

That is the same philosophy as Toyota, with whom I am profoundly in synch

Their objectives are, and have been for decades, to get to sustainability, and they will are determined to be a major player in transport whatever is powering it.

So for them too: 'All of the above'

The winners will make themselves known as things develop.

' These new fuel-agnostic engine platforms will feature a series of engine versions that are derived from a common base engine, which means they have a high degree of parts commonality. Below the head gasket of each engine will have similar components and above the head gasket will have different components for different fuel types. Each engine version will operate using a different, single fuel.

This is an industry first. These are the first engine platforms to be intentionality designed with commonality in mind for both the engine footprint and components across fuel types.

This technology approach will be applied across Cummins’ X-Series, L-Series and B-Series product platforms, which will be available for diesel, natural gas and hydrogen, and will springboard the ability of our customers to customize their transitions to zero.'

https://www.cummins.com/news/2022/02/14/cummins-new-low-carbon-fuel-agnostic-engine-platform-strategy

@SJC

Its a source of great hope to me that we don't have to be clever, just stop being so dumb and wasteful!

The problem with biogas is that about 40% of the gaseous product is CO2, not CH4.  That doesn't include the carbon which winds up in the liquid effluent.  When the carbon in the input is the main constraint on the ability to displace fossil fuels, any loss of carbon needs to be looked at very closely.

Which has exactly squat to do with the carbon economy of biogas systems.