[alancalverd]

Green steel my anal orifice. The wind drops, the furnace switches off, and another week's production doesn't go down the drain - or anywhere. Quality control? You jest. Likewise green cement.

It's actually easier per kilowatt to convert industrial users (the other half of the UK consumption of LPG) because there are fewer, bigger burners, everyone knows where they are, and you can plan the replacement with a reasonable certainty that someone will be there on the day and let you in to do the work. The problem arises if a factory is on the same grid branch as Mrs Jones who doesn't hold with this newfangled hydrogen stuff, so the day after you convert Smith's Garage, Mrs Jones's kitchen blows up - or worse, the kettle won't boil*



*the Blitz spirit. "House demolished? Have a nice cup of tea, dear."

[Petrochemicals]

Green steel

Produced using hydrogen gas, if you have a ready supply, no c02, I mean we could have half the world asking their governments to buy it over coked steel because of climate change.

[alancalverd]

But, to misquote Mrs Beeton, first make your hydrogen. Our ridiculous government is now giving your money to a bunch of foreigners to make "green steel" in Wales by adding fairy dust to the ore that has been mined by non-carbon-emitting elves.

[Petrochemicals]

But, to misquote Mrs Beeton, first make your hydrogen. Our ridiculous government is now giving your money to a bunch of foreigners to make "green steel" in Wales by adding fairy dust to the ore that has been mined by non-carbon-emitting elves.

I see. That is rubbish of course, green steel does not produce steel, merley recycle it. It's so big in Scandinavia because they are virtually all powered by very low cost hydro electric, along with their heating, electric cars are also big business due to the high oil price. If I lived in Norway I'd have an electric car too, the pay back date is about 10 years.

[Petrochemicals]

But, to misquote Mrs Beeton, first make your hydrogen. Our ridiculous government is now giving your money to a bunch of foreigners to make "green steel" in Wales by adding fairy dust to the ore that has been mined by non-carbon-emitting elves.

I see. That sort of green steel is a misconception of course, that steel does not produce steel, merley recycle it. It's so big in Scandinavia because they are virtually all powered by very low cost hydro electric, along with their heating, electric cars are also big business due to the high oil price. If I lived in Norway I'd have an electric car too, the pay back date is about 10 years.

[alancalverd]

Hydroelectricity and in a few rare cases geothermal are the only industrially useful renewables available at present. Unlike solar, wind or tidal power they are available in the required quantity at a fixed cost 24/7. Problem is that you need seriously big mountains or dangerously unstable tectonics, which are absent from the UK.

That said, 10 years is a long time in terms of car life, and vehicle batteries degrade with use or non-use. But it is fun to drive up a Norwegian mountain in an electric vehicle and avoid all that gear changing!

[acsinuk (OP)]

Green hydrogen is only produced by pure electrolysis but the gas cannot be liquified without extremely expensive cooling and pressurising.  To use hydrogen fuel in a car is nonsense as the source of electric fuel is a battery so why not just drive the motor/wheels directly.
To liquify hydrogen we normally combine it with carbon and hydrocarbon is of course diesel or refined into petrol and produces water and CO2.
Alternatively, we could press the hydrogen into nitrogen and make costly ammonia NH3 but only 50% concentrated or it becomes unstable/explosive.  Another alternative is hydrogen peroxide but even a concentration of 10% could be dangerously explosive on hot summer days.
Hydrogen gas is therefore not really suitable as a fuel unless you have a surplus of electric hydro or geothermal power as already established by other posts and have no batteries to charge and store the energy.
For the grid; nuclear is the best low carbon fuel option but population explosion is the real cause of the extra CO2 in the air and climate change.

[paul cotter]

Ammonia liquefies at-33c or by modest pressure and is completely stable as a liquid. Hydrogen peroxide is an oxidizer and not a fuel.

[Petrochemicals]

Hydrogen gas is therefore not really suitable as a fuel

https://en.m.wikipedia.org/wiki/Coal_gas

[alancalverd]

Sadly, nuclear is not a low-carbon fuel! The quantity of fossil fuel required to build a nuclear power station  is such that the energy payback period is around 10 - 20 years, with a probable life to major overhaul of 25 years. It made sense to build nukes in the 1960s when diesel was cheap, but no longer.

Hydrogen is so unsuitable as a fuel that you can already buy hydrogen-powered trucks and trains - ideal for the present market as they run between fixed depots: we need a better distribution grid to service cars and vans, but it's entirely feasible, and several local authorities already use hydrogen vans. 

Liquid hydrogen is good for rockets, but current technology for surface transport uses 150 bar gas tanks. Work is ongoing to certify 300 bar tanks for road use. At more than 10 times the energy density of a battery, a hydrogen tank and fuel cell is the ideal power source for a car.

[Petrochemicals]

A fuel cell is also around twice as efficient, meaning half the fuelneeded. But as for the infrastructure needed for hydrogen vehicles it is a tough one. Given that in the future over half of vehicles will be driverless I can imagine their will be an all together different version of the horseless carriage.

[alancalverd]

the infrastructure needed for hydrogen vehicles it is a tough one.

It already exists. The primary gas grid, which used to carry 50% hydrogen, now carries methane at 150 bar. No problem in principle switching to 100% hydrogen.

Because you can refuel a hydrogen vehicle in pretty much the same time as a diesel, you don't need to dig up all the roads and install ten million recharging points, just gradually replace garage pumps or build new refuelling stations at convenient points where the primary grid runs near a road.

[Petrochemicals]

the infrastructure needed for hydrogen vehicles it is a tough one.

It already exists. The primary gas grid, which used to carry 50% hydrogen, now carries methane at 150 bar. No problem in principle switching to 100% hydrogen.

Because you can refuel a hydrogen vehicle in pretty much the same time as a diesel, you don't need to dig up all the roads and install ten million recharging points, just gradually replace garage pumps or build new refuelling stations at convenient points where the primary grid runs near a road.

Are you sure of this? I do not remember my gasometer being 150 or 300 bar rated, nor does it shoot out of my cooker at such a rate, my petrol station also has these tankers arrive so I do not think it has piped fuel at present. Also my petrol station is not sealed against atmospheric interaction, you just sort of stick a hose in the car.

[Bored chemist]

The primary gas grid, which used to carry 50% hydrogen, now carries methane at 150 bar. No problem in principle switching to 100% hydrogen.

It's currently busy carrying methane.
Switching would require a changeover comparable with the switch to North Sea Gas in the 70s.

OK we did that; but Gas was under state ownership and there were fewer houses and fewer appliances.
It's not going to be trivial.


BTW would someone tell the ignoramus PC that he's not connected to the 150 bar gas grid in much the same way that he's not connected to the 132KV electricity grid.

[alancalverd]

Not a trivial exercise, but then neither is the exhaustion of fossil fuel, trebling the electricity grid capacity, installing 5 days' electricity storage capacity, ripping up the roads to install charging points, replacing all vehicles with BEVs, replacing all the gas boilers with heat pumps, replacing all domestic gas cookers with electric ones, and converting the whole of industry to whatever electrical machinery can melt steel and fire ceramics.

In comparison, undoing the 1960's gas conversion exercise district-by-district and ending up with a wholly sustainable energy supply looks like a doddle. In fact there aren't all that many new gas appliances compared with say 1966 - previously many homes had several gas fires and possibly two wallmounted water heaters:  almost all new and refurbished stock has a single boiler.

All it takes is a competent government - the alternative being civil war.

[alancalverd]

Also my petrol station is not sealed against atmospheric interaction, you just sort of stick a hose in the car.

Worth looking at existing LPG pumps (there are quite a few at garages) and hydrogen dispensers. The nozzle makes a gastight seal to the vehicle, and unlike LPG, the hydrogen filler doesn't accumulate ice as you fill!.

Whilst garages don't generally have piped supplies of liquid fuel, all major airports do - there is a JETA1 grid that AFAIK also supplies the military.   

[Petrochemicals]

Also my petrol station is not sealed against atmospheric interaction, you just sort of stick a hose in the car.

Worth looking at existing LPG pumps (there are quite a few at garages) and hydrogen dispensers. The nozzle makes a gastight seal to the vehicle, and unlike LPG, the hydrogen filler doesn't accumulate ice as you fill!.

Whilst garages don't generally have piped supplies of liquid fuel, all major airports do - there is a JETA1 grid that AFAIK also supplies the military.   

I have seen the hydrogen dispensers, about the size of a shipping container, butane is known to be more easy to handle than propane, plastic containers of butane with  flint* on top are in the pockets of smokers world wide, hydrogen  under pressure is a quite different story. Don't forget that lpg is so appealing because it is not under the same tax rates as oil, I doubt it would compete without that.

*ferrocerium

[alancalverd]

LPG doesn't attract the same tax rate per liter as oil, but has a rather lower energy density and its combustion in an IC engine is less efficient than gasoline or diesel so in terms of cost per mile it isn't all that economical. And tax rates are based on politics, not physics, so have no rational basis. Butane is a poor road fuel because it has a very low vapor pressure at ambient temperatures: propane is a lot easier to control.

The current hydrogen road fuel dispensers are very large because there are no (or very few) underground tanks. The 150 bar tank on a small car (which gives you about 300 miles of range) is about the size of the conventional gasoline (400 mile) tank.

[Bored chemist]

whatever electrical machinery can melt steel

"The German-born British inventor Sir William Siemens first demonstrated the arc furnace in 1879 at the Paris Exposition by melting iron in crucibles. "

From
https://www.britannica.com/technology/electric-furnace

Whilst garages don't generally have piped supplies of liquid fuel, all major airports do

I'm a long way from convinced about hydrogen powered planes.

[Petrochemicals]

Lpg has a density lower in volume but higher for mass, one would imagine that it would be ideal for jet engines, clean burning easily mixed, but for some reason it inst used, perhaps it's those 4 bar pressure vessel's weight

https://www.gasproducts.co.uk/gas-regulators/propane-gas-regulators-high-pressure/reca-912-0-5-4-bar-high-pressure-propane-gas-regulator.html