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Offline photografr7

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hydrogen production
« on: March 14, 2015, 11:16:21 PM »
Since electrolysis, what have been the most important advances in the mass production of hydrogen?

-- Bill

Offline curiouscat

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Re: hydrogen production
« Reply #1 on: March 14, 2015, 11:39:44 PM »
Water gas shift. Cracking & other  H2 generating processes in refining. H2 from biomass. H2 from natural gas. Syn gas generation from coal. H2 from methanol reforming.

Offline Enthalpy

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Re: hydrogen production
« Reply #2 on: March 15, 2015, 06:46:58 PM »
Electrolysis doesn't produce hydrogen on a big scale because
- Hydrogen is strongly bonded to oxygen, costing too much energy to separate. Obtaining it from a hydrocarbon needs less;
- Electricity is an expensive form of energy.

This means that, in the present context, running cars on hydrogen isn't very eco-friendly. It takes fossil fuel like natural gas to produce hydrogen, and the leftovers may be burnt.

Though, this can improve.
- At extraction, the C3 and C4 fractions of oil are burnt. They could be converted instead.
- Methods would exist to mass-produce hydrogen, they are only too expensive now because they're underdeveloped and because competing hydrocarbons are too cheap.
- When using methane to make hydrogen, could the leftovers be chosen and used as gasoline, instead of burnt?

So it's very much a matter of cost. Do we want to build boats to transport hydrogen? Invest in production methods?

Offline billnotgatez

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Re: hydrogen production
« Reply #3 on: March 15, 2015, 09:07:24 PM »

Offline curiouscat

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Re: hydrogen production
« Reply #4 on: March 16, 2015, 01:16:11 PM »
Quote
At extraction, the C3 and C4 fractions of oil are burnt

I don't think this is true, in general. Propane  / Butane are useful commodities.

Offline billnotgatez

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Re: hydrogen production
« Reply #5 on: March 16, 2015, 02:47:41 PM »
Below is all the recent news I have kept a list of about hydrogen.
You can probably find more using GOOGLE

http://phys.org/news/2014-09-hydrogen-production-breakthrough-herald-cheap.html
http://phys.org/news/2015-02-team-hydrogen-production-extreme-bacterium.html
http://www.gizmag.com/water-splitter-aaa-battery-hydrogen-fuel-cell/33497/

http://phys.org/news/2015-03-hydrogen-bond.html

http://www.fool.com/investing/general/2014/10/01/this-is-how-you-know-hydrogen-fuel-cells-are-ready.aspx
http://phys.org/news/2014-08-hydrogen-fuel-cell-vehicle-rollout.html

As noted by WIKI
Quote
Currently, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming or partial oxidation of methane and coal gasification

With all the cheap sources of natural gas coming on line, I am not sure how much research is going on in  other hydrogen production techniques.
 

Offline Arkcon

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Re: hydrogen production
« Reply #6 on: March 16, 2015, 08:18:38 PM »
Quote
At extraction, the C3 and C4 fractions of oil are burnt

I don't think this is true, in general. Propane  / Butane are useful commodities.

http://geology.com/articles/oil-fields-from-space/

Some of these are artificial lights, but flaring off of natural gas isn't rare, not by a long shot.  Often, it simply isn't cost effective to insert the infrastructure, and maintain it, for the local population to pay for.  Setting up a local industry to use the fuel seems to be the best bet to avoid waste, but that still needs heavy government subsidy.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Enthalpy

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Re: hydrogen production
« Reply #7 on: March 16, 2015, 08:57:38 PM »
Propane and butane are useful, but not in the amounts available at the wells... Alas, they are difficult to transport together with methane and together with oil, because the liquid ranges fit badly - and since oil and gas are so cheap that their transport is a significant fraction of the sale price, C3 and C4 go often to the flare.

Few years ago the oil industry committed itself to use "more" of these fractions in order to limit the CO2 emissions. Running cars on this Liquefied Petrol Gas was seen as a solution: as these gas would burn anyway, any use would be pure profit - but this market didn't grow much.

Could we make hydrogen of them? Only if hydrogen is expensive enough... A separate transport from the well to a cracking unit looks expensive. Maybe a small plant can operate near the wells, produce hydrogen and small alkenes sent to an alkylation unit or a polymer unit. But this needs to ship hydrogen; no difficult technology, it's just an investment.

Offline curiouscat

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Re: hydrogen production
« Reply #8 on: March 18, 2015, 12:18:36 AM »
Quote
At extraction, the C3 and C4 fractions of oil are burnt

I don't think this is true, in general. Propane  / Butane are useful commodities.

http://geology.com/articles/oil-fields-from-space/

Some of these are artificial lights, but flaring off of natural gas isn't rare, not by a long shot.  Often, it simply isn't cost effective to insert the infrastructure, and maintain it, for the local population to pay for.  Setting up a local industry to use the fuel seems to be the best bet to avoid waste, but that still needs heavy government subsidy.

Agreed. I wasn't saying it is not done. Just that not all C3 / C4 streams are burnt.

As an aside, anyone know what fraction of C3 + C4 produced is actually burnt in flares today? Prices are high enough that liquification makes sense for a lot of stranded gas. Especially since C3 / C4 is a lot easier to liquify than CH4.

Also, there's good small turbines for power generation; I wonder if remote sites use any of those to generate electricity from excess C3/C4.

Offline curiouscat

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Re: hydrogen production
« Reply #9 on: March 18, 2015, 12:21:00 AM »
Propane and butane are useful, but not in the amounts available at the wells... Alas, they are difficult to transport together with methane and together with oil, because the liquid ranges fit badly - and since oil and gas are so cheap that their transport is a significant fraction of the sale price, C3 and C4 go often to the flare.

Do you know what fraction of propane + butane produced are flared away? I'd be curious to know.

Methane is indeed difficult to transport but noting the very very large capacity LNG plants, GTL plants, gas pipelines & the spike in orders for LNG carriers it must be an expanding market?

Offline Enthalpy

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Re: hydrogen production
« Reply #10 on: March 19, 2015, 01:10:07 PM »
Oil and gas wells use to be far from electricity consumers, and transporting hydrocarbons by boat needs less investment than electricity by a power line. In addition, wells give C3+C4 at the same time that they produce methane or oil: irregularly, when the main customers needs it, not when the electricity consumers want. So for the electricity mass-market, I'd say it's better to transport the hydrocarbon to a power plant near the consumers.

Make electricity for the needs of the well: maybe. It's just that the teams need electricity when the well doesn't produce or before it does, and in amounts negligible with the well's production. So they have Diesel generators from the beginning; you may try to convince them to purchase a propane turbine too.

Liquefy and store briefly the C3+C4 at the well, have special boats (easier than methane, true) to carry it to main power plants or refineries? That sounds better.

Gas turbines run more easily with propane+butane than with methane or coal and lend naturally to a combined cycle. At a big power plant, your competitor is coal and presently shale oil+gas, which are cheap. Though, shale oil already depletes, and propane emits less CO2 than coal, so you might feed some power plants with them.

My gut feeling is that refineries would make the best use. Hydrogen is useful and propylene must presently be converted from ethylene to make enough polymer; butylene (mainly iso-) is a big feed of alky units.

What proportion of C3+C4 is flared at the well? No recent information. Few decades ago, it was: all, except at few wells. Maybe two years ago, oil and gas producers committed themselves to flare a bit less of them.

Offline Arkcon

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Re: hydrogen production
« Reply #11 on: March 19, 2015, 01:51:48 PM »
I remember when I heard about Single Cell Protein -- using methane and C3-C4, to produce protein concentrates for use as animal feed and even human consumption: http://en.wikipedia.org/wiki/Single-cell_protein#.22Food_from_oil.22  It seemed bizarre to me, at the time, to use a petroleum product to culture food microbes, but the instructor told me, much of the lower molecular weight hydrocarbon fractions are just flared off.  The dilemma is, again, the cost of setting up infrastructure for production, even if the product is easily shipable.

Some places are trying to merge industry with the larger, more permanent, oil fields.  Hydroponic greenhouses -- based on sand media in the Middle East or in Canadian shale oil fields (using bark culture from nearby logging) remain popular -- experimentally, as pilot plants or even major production.  Again, infrastructure costs remain significant, and the slightest market effects can make these sorts of production fractionally unprofitable at any time, and the industry just vanishes.   The C3 and C4 is still there, and it seems to me the only consistent use is to flare it and make interesting photo op from space.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Enthalpy

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Re: hydrogen production
« Reply #12 on: April 15, 2015, 05:29:58 AM »
My gut feeling is that refineries would make the best use. Hydrogen is useful and propylene must presently be converted from ethylene to make enough polymer; butylene (mainly iso-) is a big feed of alky units.

Not very original... From the "Production" chapter, paragraph "propane dehydrogenation":
http://en.wikipedia.org/wiki/Propylene
Numerous plants dedicated to propane dehydrogenation are currently under construction around the world.

Butane to butene(s) to alkylation could be less common - but if propylene is in high demand, cracking and metathesis can convert butene to propene.

Less fun for the production of hydrogen: Wiki's article tells that is serves to heat the propane dehydrogenation unit... ;D But if a demand for hydrogen exists, and near enough to the customers, some propane could heat the unit, and the hydrogen be collected.

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