Alternative fuels for railways

[The Johnster]

Bicycles are not green, in fact mine is yellow. One needs to consume more food than one would otherwise in order to power them, and the carbon footprint and fuel costs of providing this easily outweigh saved the exhaust and fuel footprint of the cycle use that did not involve car or public transport.

 

No such thing as a free lunch.

[Nearholmer]

True, mine is mostly black.

 

I am probably taking you far too seriously, but,

 

- if like me, you need to shed a few kg, it is possible to power your bicycle from personal fat reserves, simply by eating as normal and becoming thinner;

 

- Once the fat reserves are exhausted, no way will you need to eat more energy to cycle than is consumed by lugging a car around on every trip ....... a car with one occupant burns ten or twenty times the energy per km as is burned per km by a cyclist.

 

And, I reckon it's more pleasurable to spend money on cakes (sorry, I meant wholesome health foods) than on petrol.

Edited May 1, 2018 by Nearholmer

[jjb1970]

The most obvious way to reduce emissions from trains is indeed to electrify, provided of course that the electrical supply comes from a low emissions source. There are however lines where this is unlikely to be practicable, at least not for a long time, and of course this country has shot itself in the foot by seemingly managing to make electrification unaffordable. So there will be an ongoing requirement to operate trains on non-electrified routes for the foreseeable future.

 

If we look at these trains which will operate on non-electrified routes then I see quite a few options, many of which are technically mature. Although I normally agree with Roger Ford and consider him one of the few people writing in magazines who genuinely knows what he is talking about and with an ability to do his own technical analysis I do not agree with his latest article on bionic duckweed. This is a rapidly evolving field and some options which may appear fantastical to many (including to Uncle Roger it seems) could reach technical maturity much more quickly than we might imagine. There is a lot of work on next generation bio-fuels, to be honest I’m not a fan of bio-fuels (although the European Commission is for some reason) but next generation fuels aim to address the concerns around existing products such as FAME. One of my concerns is that even for some of the newer fuels it is unclear whether they genuinely reduce GHG emissions.

 

Natural gas/methane has been used in engines for many decades and most if not all of the engine builders can provide gas fuelled versions of their engines. For a train you could store the fuel as liquefied natural gas (LNG) or potentially compressed natural gas (CNG) for smaller trains. Technically it’s all very straightforward and there are no real issues with engine performance, local emissions such as NOx, SOx and PM are lower than for oil fuels too. There is an issue with methane slip, most smaller gas engines favour a low pressure gas technology (for obvious reasons) and so are modelled on the Otto cycle or similar. Gas Otto engines can be associated with high methane slip which is a much worse GHG than CO2. Gas Diesel engines have negligible methane slip and more efficient combustion but need a high pressure gas supply, if you use LNG fuel that is less of a problem as lifting the pressure of a liquid doesn’t need much energy but compressing gaseous fuel up to 300bar+ in the volume needed for a large engine needs an awfully powerful compressor. The parasitic load of such a compressor can be heading for 10%. Although natural gas has a lot of advocates it’s still a hydrocarbon fuel and the carbon factor isn’t that much lower than oil (although it is lower, circa. 20% lower).

 

A liquid alternative is methanol/methyl alcohol. That can be used in engines relatively easily, has excellent local emissions (SOx, NOx, PM) and a lower carbon factor than oil however it needs careful risk management and although you can make renewable methanol most commercially available methanol is derived from natural gas feedstock.

 

The great hope is hydrogen, you can actually use hydrogen in a regular engine but you then still have NOx emissions and can have hydrogen peroxide emissions so it’s probably better to use it in a fuel cell. Fuel cells can be very efficient, particularly high temperature types with heat recovery. They cell stacks can be expensive though and in some cases can be easily poisoned or have quite a short life. The issues aren’t really about the fuel cells though, it is where does the hydrogen come from, and hydrogen storage. Liquefied hydrogen is within 20C of absolute zero (it makes LNG look warm and toasty) and for rail use if you used hydrogen in its natural state you’d probably need compressed hydrogen gas. Some of the issues often mentioned such as hydrogen permeability and embrittlement can be managed perfectly well (hydrogen is widely used as a coolant gas for electrical generators and we don’t see many stories of power stations blowing up). Traditionally the energy intensity of producing hydrogen meant it was not really much of a help in environmental terms but the rise of renewable energy has changed that and now it is possible and indeed entirely viable to produce clean zero emissions hydrogen. For transport fuels it may be easier to use a hydrogen carrier such as ammonia, the OECD are really promoting ammonia as the cure all fuel for shipping. Ammonia as a nitrogen – hydrogen compound is free of carbon but again much depends on how you make the stuff.

 

I really see a lot of potential for batteries. The energy density and recharge times of batteries are improving rapidly and new battery chemistries are in development to address the issues around use of unpleasant and limited metals. Liquid flow batteries already address the recharge time issue and their energy density is also improving rapidly. Recharge batteries using renewable electricity and hey presto, job pretty much done.

 

This isn’t exhaustive. There are options and there is serious money going into these options. Far from being bionic duckweed I think you’ll see alternative fuels and energy conversion develop faster than most anticipate.

[pete_mcfarlane]

'Gas' in that case was vaporised aviation fuel, not compressed gas such as LPG, Methane and Hydrogen.

 

You can also have solid fuel powered gas turbines. 

 

https://www.classicstreamliners.com/lo-up-8080.html

https://en.wikipedia.org/wiki/Lippisch_P.13a (although technically that's a ramjet)

[frobisher]

While hydrogen is most certainly the cleanest fuel AT POINT OF USE and a dribble of water from the exhaust pipe the only 'pollution' more than is produced by an electric vehicle - everybody forgets that neither of these actually grows on trees so some sort of 'factory' is needed - either a fuel-hungry plant to split water into hydrogen & oxygen then compress the former for use or a power station - of some sort - for the electric.

Orkney currently has a severe excess of electrical production (from renewables) relative to the infrastructure to be able to return it to the grid, and funnily enough hydrogen production is being very actively pursued as a way to utilise (and indeed grow) this excess.

[jjb1970]

The gas in a GT is a product of combustion, the fuel combusted can be gaseous, liquid or solid.

[jonny777]

The interesting thing about electricity demand is that over February and March we had some of the coldest winds (with significant snowfall) that we have experienced for many years, and yet demand did not exceed UK supply at any time. 

 

When I worked in meteorology we liased closely with energy utility companies, and they were quite happy for an exchange of information on their jobs and ours. What came over quite regularly was that demand is a function of mainly wind and temperature, and so although people believe that on a freezing foggy night with no wind and air temperatures of -10C the demand will be at its max and we will not be able to cope. This is not true, because it doesn't feel as cold as maybe temperatures hovering around zero with a gale blowing when demand will skyrocket, but wind generation will be high. 

 

It was noticeable in Feb/Mar that because gas prices had tripled due to demand, our coal/biomass, nuclear and wind generation was ramped up as high as could be maintained in order to allow gas generation to be cut back to save money. This is the flexibility that wind gives. 

 

Yes it cannot be guaranteed as a base load, but nuclear has been refurbished into the next decade and soon the wind capacity will have increased from 12 to 20GW. 

[APOLLO]

As a retired gas engineer with 40 years at the sharp end both in operations (gas leakage / mains renewal) and planning (replacement gas mains) I can vouch cold, still winter nights 4pm - 8pm is when the gas load (and no doubt electricity also) is highest.

 

As gas loads grew, especially in the 1980's, every very cold peak evening we were out checking pressures in affected areas (poor pressures at peak times due to load growth). We did a hell of a lot of work replacing mains with larger ones, reinforcement mains, etc. Over time the gas pipeline systems nationwide were made fit for purpose, and not many problems occur locally these days - BUT the problem is still security of supply at peak times. Yes certain large loads are interuptable and this helps, along with many other methods. Remote / end of system locations are automatically monitored and pressure adjusted to demand.

 

These days it's gas injection into the system to balance demand that is all important, )as is electricity generation into the grid). 

 

Gas is easily stored these days by line packing the high pressure transmission mains, most low pressure holders have gone. There is LNG storage and salt cavity storage also, but a depleted field in the North Sea used for storage until recently has been found to have serious geological problems and to be decommissioned - a bit of a serious blow as it held quite a lot of gas (it was filled in summer months). The nation currently does have a bit of a gas storage problem for very cold prolonged winter spells.

 

Storing electricity (as mentioned) is a different kettle of fish - more work is required and indeed is being done.

 

Brit15

[jjb1970]

Nice chilly cold gas are good for gas turbines, at the CCGT plant I worked at for a while each GT would see a difference of around 7MW output between a chilly winter day and warm summer day.

[APOLLO]

I've said this before, and I'll say it again - with our (UK) railways - electrify the lot.

 

Branch lines etc can be done at low voltages (like Manchester trams). Isn't the Sheffield - Rotheram "tram train" pioneering this technology ?. Such a shame the lying conniving politicians, along with incompetence within Network Rail, contractors etc have seemingly put the kybosh on current rail electrification.

 

I'm sure such as the Windemere branch could be electrified this way quite cheaply, and some existing (or even new) trains adapted to dual voltage.

 

The Americans (as usual) were miles ahead with their electrified interurban networks back in the early 20th century - unfortunately they just got a decent system in place and the automobile killed them off. 

 

 

 

A simple wire on a series of poles. Low tech, low cost, and IT WORKS !! (well it did 100 years ago !!).

 

By the way, how about bringing back trolleybuses ?. With the application of modern technology using batteries in town / city centres, overhead  wires out of town providing both traction & recharging simultaneously. We had a good trolleybus system here in South Lancashire - the diesel bus killed it for some reason in the early 60's.

 

Electricity IS the way forward (for cars also) though there are many hurdles to overcome - Generation, Storage, Emissions (generation) Capability of both the grid and LV networks to supply increased loads etc. The biggest hurdle I see is political will.

 

Brit15

Edited May 1, 2018 by APOLLO

[Edwin_m]

By the way, how about bringing back trolleybuses ?. With the application of modern technology using batteries in town / city centres, overhead  wires out of town providing both traction & recharging simultaneously. We had a good trolleybus system here in South Lancashire - the diesel bus killed it for some reason in the early 60's.

I'd say trolleybuses have most of the disadvantages of both buses and trams.  They need fixed infrastructure (more visually intrusive than that for trams) and are therefore confined to specific routes.  But they can't be any bigger than motor buses so can't offer any extra capacity, especially as they can't overtake each other (trams can't either, but they are bigger with more doors so tend to bunch together far less).  The use of rubber tyres rather than steel rail means the energy consumption is significantly more than for a tram of the same size. 

 

It's likely that the common or garden bus will respond to the technical challenge.  The link below illustrates how mainstream battery buses are, being produced in phenominal numbers in China and each saving the emissions of 30 cars*.  We have some of these in Nottingham but also a fleet of double-deckers that run on compressed natural gas derived from sewage treatment, so are close to carbon-neutral and indistinguishable from a the rest of the fleet apart from being a bit more modern.  So between those and trams it's likely that the niche for trolleybuses is small to zero, even when the elimination of diesel is taken into account. 

 

https://www.bloomberg.com/news/articles/2018-04-23/electric-buses-are-hurting-the-oil-industry

 

*Not because a bus emits 30 times as much per mile as a car!  I presume this statistic takes account that buses are operating for a much larger proportion of the time than cars are. 

[tigerburnie]

After the monumental cock up of installing trams in Edinburgh, I doubt you'll see any appetite for anything resembling them any where north of the border unless they are under ground.

[APOLLO]

After the monumental cock up of installing trams in Edinburgh, I doubt you'll see any appetite for anything resembling them any where north of the border unless they are under ground.

 

They seem to do quite well in and around Manchester - a superb system.

 

Brit15

[brack]

Hydrogen is currently the obvious answer, for cars. Unfortunately the cheapest way to make it tends to be using methane as a feedstock (same with ammonia).

Electrification of railways is a clear and proven technology and has been ready/mature enough to use on all main line routes for a century. Dieselisation was a short term cheap fix, and an expensive long term solution. Regenerative braking also allows reduction of energy demands in hilly sections.

To provide the electricity I'd argue a blend of renewables, high temp incineration/power/district heating plants and baseline nuclear (probably using multiple small reactors based upon proven submarine technology unless thorium gets off the ground).

 

There is one other completely carbon neutral solution.

 

http://www.theheritageportal.co.za/sites/default/files/styles/adaptive/public/articles/Train%20on%20the%20Benguela%20Railway.jpg?itok=2UMUgAo8

 

The Benguela railway owned large eucalyptus plantations and produced its own fuel to power some rather nice garratts (and some 4-8-2s based on the 19D). Completely renewable and sustainable.

[jjb1970]

The future for nuclear is sealed packaged "plug in" reactors I think. Eliminate most of the security and re-fuelling cycle concerns, build in ease of recycling, keep the difficult bits in a reactor production facility so that plant design and build effectively becomes a small thermal plant with a plug in reactor unit.

[APOLLO]

The future for nuclear is sealed packaged "plug in" reactors I think. Eliminate most of the security and re-fuelling cycle concerns, build in ease of recycling, keep the difficult bits in a reactor production facility so that plant design and build effectively becomes a small thermal plant with a plug in reactor unit.

 

Have you any links to further explain plug in reactors jib ?  I've never heard of them - seems interesting.

 

Brit15

[jjb1970]

This was one concept:

 

http://www.uxc.com/smr/Library%5CDesign%20Specific/G4M%20(HPM)/Other%20Documents/Brochure%20Hyperion%20Module.pdf

 

I did a bit of work for them a few years ago as before the Fukushima incident shipyards were developing merchant ship designs to use the concept. Unfortunately it all went pear shaped however a few other companies have been working on similar concepts.

[Nearholmer]

Submarine technology, presumably?

[melmerby]

The Russians have just  commisioned a floating Nuclear power station.

 

https://en.wikipedia.org/wiki/Russian_floating_nuclear_power_station

 

Keith

[melmerby]

I'd say trolleybuses have most of the disadvantages of both buses and trams.  They need fixed infrastructure (more visually intrusive than that for trams) and are therefore confined to specific routes.  But they can't be any bigger than motor buses so can't offer any extra capacity, especially as they can't overtake each other (trams can't either, but they are bigger with more doors so tend to bunch together far less).  The use of rubber tyres rather than steel rail means the energy consumption is significantly more than for a tram of the same size. 

 

Modern electric/battery trolley buses could overtake as nowadays automatic trolley pole alignment exists so if one comes across another one, stationary for some reason, it could down poles, overtake on batteries then raise the poles again.

Also routes can be varied as as long as enough is wired to keep the battery charged they can wander off wire to serve different destinations.

Articulated trolley buses are also available which overcomes much of the capacity limit. They can also, with hub motors, be almost completely low floor unlike a tram.

https://i.ytimg.com/vi/pMbOYgjCFGc/maxresdefault.jpg

 

Keith

[brianusa]

I've said this before, and I'll say it again - with our (UK) railways - electrify the lot.

 

Branch lines etc can be done at low voltages (like Manchester trams). Isn't the Sheffield - Rotheram "tram train" pioneering this technology ?. Such a shame the lying conniving politicians, along with incompetence within Network Rail, contractors etc have seemingly put the kybosh on current rail electrification.

 

I'm sure such as the Windemere branch could be electrified this way quite cheaply, and some existing (or even new) trains adapted to dual voltage.

 

The Americans (as usual) were miles ahead with their electrified interurban networks back in the early 20th century - unfortunately they just got a decent system in place and the automobile killed them off. 

 

 

 

A simple wire on a series of poles. Low tech, low cost, and IT WORKS !! (well it did 100 years ago !!).

 

By the way, how about bringing back trolleybuses ?. With the application of modern technology using batteries in town / city centres, overhead  wires out of town providing both traction & recharging simultaneously. We had a good trolleybus system here in South Lancashire - the diesel bus killed it for some reason in the early 60's.

 

Electricity IS the way forward (for cars also) though there are many hurdles to overcome - Generation, Storage, Emissions (generation) Capability of both the grid and LV networks to supply increased loads etc. The biggest hurdle I see is political will.

 

Brit15

How appropriate, as now there are plans afoot to connect Tacoma to Seattle by light rail costing billions, when it was all there many years ago.  It lasted until the late thirties when the first freeways were beginning to appear which are now overwhelmed and takes longer than did the old electrics.

 

Brian.

[The Johnster]

True, mine is mostly black.

 

I am probably taking you far too seriously, but,

 

- if like me, you need to shed a few kg, it is possible to power your bicycle from personal fat reserves, simply by eating as normal and becoming thinner;

 

- Once the fat reserves are exhausted, no way will you need to eat more energy to cycle than is consumed by lugging a car around on every trip ....... a car with one occupant burns ten or twenty times the energy per km as is burned per km by a cyclist.

 

And, I reckon it's more pleasurable to spend money on cakes (sorry, I meant wholesome health foods) than on petrol.

 

I could do with shedding a few lbs, not kgs as I still weigh myself in old money, but this is not the reason I cycle; I do that because I enjoy it.  Any health or other benefits are a free bonus.  But fat reserves are not free fuel, as I had to burn resources in order to pay for the food that put them there in the first place, and of course that food and it's production and distribution had a carbon footprint.  

 

A car not only burns 20 times the energy per km of a cyclist, but it does it in much less time so that an hour's journey takes you much further away, unless you are in Cardiff rush hour traffic which is the slowest in the UK.  It is fairer to compare the energy consumption of the cyclist and the car over a journey of say 2 hours by car which will take a fit cyclist on a fast road bike about 8 to 10 hours.  Of course, the car's driver burns much less energy...

 

I agree about the cakes, though.

[david.hill64]

According to an article in The Times today, the rail minister has ruled out electrification and is relying on battery power and hydrogen.

 

I wonder why nobody suggests getting the costs of electrification under control by:

 

a) reverting to the BR standard on clearances, and

 

b) using basic project management techniques?

[jjb1970]

The Russians have just  commisioned a floating Nuclear power station.

 

https://en.wikipedia.org/wiki/Russian_floating_nuclear_power_station

 

Keith

No no no!! They've just commissioned a floating Titanic Chernobyl, I read this in a very temperate, balanced article in our esteemed press which was absolutely not scare mongering and using lazy stereotypes.......

[jjb1970]

According to an article in The Times today, the rail minister has ruled out electrification and is relying on battery power and hydrogen.

 

I wonder why nobody suggests getting the costs of electrification under control by:

 

a) reverting to the BR standard on clearances, and

 

b) using basic project management techniques?

Unfortunately it appears to be easier for people at DafT and the higher echelons of NR to agree that affordable electrification lies outside known human scientific knowledge and invention and is just not practicable rather than to admit the GWML debacle is a self created cluster **** highlighting woeful ineptitude. After all, if people woke up to the clearance issue they might ask what idiots at DafT were either sleeping at work or were too incompetent to realise the significance of the clearance issue and secure a derogation. If only the railways were nationalised none of this would be a problem apparently