Synthetic petroleum

[StrandedonEarth]

High school science (I think I learned it in Chemistry, it may have been Physics. It was a long time ago)

PV=NrT (Pressure, Volume, Number of mols, constant, Temperature) Can be re-written as:

(P₁V₁)/T₁=(P₂V₂)/T₂

 

[JebKeb]

I've been sorting out methane synthesis and stuff, so that seems sorted. Now, it seems we need to process the products of the Fischer-Tropsch reactor, because they aren't ready for use. In next post I'll explain, because IRL i have very little time right now.

[JebKeb]

After leaving the Fischer-Tropsch reactor the mixture is first put in a still, draining out the water and removing most of the petroleum gases, light olefins and alcohols. Next, it is distilled. The the carbon number decides what happens next:

C12+ dewaxing and hydrocracking into diesel

C7-11 naptha catalytically reformed into reformate, aromatics then removed

C5-C6 isomerised into isomerate

C1-C4 olefins seperated and blended, then alkylated into alkylate

other C1-C4 sold seperately

The end products would be:

Methane - back to the catalytic oxidisation reactor.

Ethane - turned into ethylene

Propane - LPG

Butane - butane

Ethylene - for plastics

Reformate, isomerate and alkylate - petrol

Benzene from reformate

Hydrocracked gas oil - diesel and kerosene

Waxes

 

[kerbiloid]

Fischer-Tropsh gives just an artificial raw material for an oil refinery plant.
Concentrations vary, of course, but this is also true for natural oils.

[todofwar]

Every time I check my journal of the American chemical society rss there's about four or five CO2 reduction papers, ranging from electrochemical to photo activated. So, clearly someone expects this to be viable since plenty of money is getting dumped into it

[JebKeb]

Does anyone know any method of removing benzene from petrol? It exists, because they're already doing it, but I can't find any methods.

[StrandedonEarth]

Presumably by fractional distillation?

[kerbiloid]

10 hours ago, JebKeb said:

Does anyone know any method of removing benzene from petrol? It exists, because they're already doing it, but I can't find any methods.

Mostly they need to remove petrol from benzene after the "aromatization" process...

Edited May 29, 2016 by kerbiloid

[JebKeb]

2 hours ago, kerbiloid said:

Mostly they need to remove petrol from benzene after the "aromatization" process...

Remove petrol from benzene?! That's a boatload of aromatics!

Now, onto something more useful...

Apparently when zinc, aluminium or silicon react with water they produce hydrogen gas and their respective oxide. This seems to be a better option than electrolysis to obtain hydrogen. But it is possible to deoxidise it efficiently?

Edited May 29, 2016 by JebKeb

[kerbiloid]

1 hour ago, JebKeb said:

Apparently when zinc, aluminium or silicon react with water they produce hydrogen gas and their respective oxide. This seems to be a better option than electrolysis to obtain hydrogen.

Using the (pure) aluminium (which can be hardly produced from alumina and cryolite mix with enormous amounts of electricity) to save energy is a really fresh look at the problem...

[JebKeb]

Well.

Alumina to aluminium. Nope. Requires arc furnaces.

With the C1-C4 hydrocarbons, there is a small amount of CO2, and also butane and butylene freeze above the boiling points of methane. A continous design would be good, because doing it in batches would not be as efficient.

So, does anyone know of any places to find state change charts for lots of compounds?

[kerbiloid]

1 hour ago, JebKeb said:

So, does anyone know of any places to find state change charts for lots of compounds?

For example, a googling of "ethane state chart" gives many state chart pictures and this nice book with tables.

[todofwar]

http://www.bbc.com/news/science-environment-36197603

[kerbiloid]

2 hours ago, todofwar said:

http://www.bbc.com/news/science-environment-36197603

Quote

They believe that the baking soda approach could be 40% cheaper than existing technology.

+ 40%...

[JebKeb]

So, I've found out about most of the stuff I wanted to, but there seems to not be very much understandable information on the isomerisation unit? Does anyone know how it works?

 

 

[kerbiloid]

https://www.google.ru/search?q=naphtha+isomerization&newwindow=1&biw=1920&bih=957&tbm=isch&source=lnms&sa=X&ved=0ahUKEwiM37vU7ZPNAhWB8ywKHYxvDBMQ_AUIBigB

Edited June 6, 2016 by kerbiloid

[JebKeb]

I've seen these. They're a bit simple. Anyway, I've sorted out this.

I've been thinking about getting more petrol by catalytically cracking the wax, because low temp FT seems to be a good bet (not too much LPG, nice lot of middle distillates). If you want to know where I got this from, here!

Does this cracker naptha need reforming to become higher octane, or is it fine to go in straight run? It looks to have quite a bit of branched paraffins.

V THIS IS NOT A NEW SUBTOPIC V

I've noticed. Low temperature cobalt FT seems to have a similar composition to Arabian Light crude. Maybe we could just sell syncrude to oil companies.

Edited June 7, 2016 by JebKeb

[JebKeb]

Everything's sorted. I'll be back with a diagram in a few days due to real life.

[WinkAllKerb'']

(( just asking a thing here, any simulation of tektonic and what we drained from the undergound (solid & liquid), and when it should have reach the core ? )) may be it's even more about refilling what we drained with bio fuel first for that now, than even using biofuel for something else

search?q=earth+core+refuel&rlz= ...
UTF-8#q=earth+core+lifespan+%26+solar+core+lifespan+comparaison

see also large undergound empty cave collapse, small tunnel collapse repercution @ sea level are thing "always" refilled like off shore in everyplace we drain large cave on earth ?

Edited June 14, 2016 by WinkAllKerb''
grats ksp ; )

[JebKeb]

4 hours ago, WinkAllKerb'' said:

(( just asking a thing here, any simulation of tektonic and what we drained from the undergound (solid & liquid), and when it should have reach the core ? )) may be it's even more about refilling what we drained with bio fuel first for that now, than even using biofuel for something else

search?q=earth+core+refuel&rlz= ...
UTF-8#q=earth+core+lifespan+%26+solar+core+lifespan+comparaison

see also large undergound empty cave collapse, small tunnel collapse repercution @ sea level are thing "always" refilled like off shore in everyplace we drain large cave on earth ?

I think I was having this as an idea too. Produce fuel from CO2 in the atmosphere and bury it for hyper evolved cockroaches to dig up and get into the same mess we're in right now.

 

[JebKeb]

The syncrude from the FT reactor appears to contain alcohols. Could you dehydrate these alcohols into olefins to improve yield a bit, and what sort of thing would you use to dehydrate it with?

[JebKeb]

I thought it would be interesting to explore the economics of this, so let's assume we have a worldwide company producing 10 million bpd of syncrude. Around 10,000 employees are needed per 10 billion litres of syncrude per year at $50K each. 10Mbpd is about 3.5 billion barrels per  year, or 600B litres per year. So, we need 600,000 employees at $50K each, wanting $3B per year total. Employees cost us half a cent per litre, or around $1 per barrel.

There really aren't any other costs, apart from loans which let's just say have been long paid off.

$1 per barrel syncrude stacks up *insert lovely word* well against the cheapest oil, from Kuwait at $8.5 a barrel, even if there are secret hidden costs that I haven't thought of yet.

[Cirocco]

Okay, I just only now discovered this thread (very sad about that btw) so I haven't read everything here, but I believe I can be of service here. Here's why:

I graduated about 6 years ago as a catalytic engineer. Half of my education was basically geared towards petrochemistry and my master thesis was about trying to find a suitable catalyst and process to selectively crack long parafins (such as the ones from a FT-reaction) into diesel-length molecules. For those interested: we tried a process where we first tried to isomerize the parafins in the middle by running it over a zeolite (ZSM-22 if my memory serves me correctly), and then trying to selectively crack them over a Pt /sulfated zirconium-silicate catalyst. Results were partially successful.

 

So, with that out of the way, here's some difficulties that you encounter in the process and hidden costs which I believe have not yet been accounted for:

- FT product distribution is heavily skewed to the long-chain parafins in absolute numbers. Yes, the peak of the distribution can be pushed more towards the diesel range by tweaking the process parameters and choosing the right catalyst, but when you look at the volume beneath the curve (which gives you an idea of the volumes produced) that tail end is still huge. Economically speaking, I don't think FT reactions are viable on a large scale (yet) due to the immense amount of by-products and energy required to perform in and purify the product. To make this economically viable you need to (as I believe has been discussed in this thread already) find a way to break down the long-chain fraction into usable, shorter chains. Which leads us to a second problem:

- Long-chain parafins have high melting points and therefore have a nasty tendency to congeal and clog up your reactor vessels and tubings. This stuff is not easy to work with, I speak from experience. Back when I did my master thesis, I was told there weren't that may reactors in the world that could handle these waxy parafins because any cold spot in the reactor or tubing thoroughly messes up everything.

- Any chemical reaction, especially petrochemical ones, always yields a slush of different chemicals. Sometimes the slush is very, very skewed to one side but in FT reactions, it is not. You need to purify it, usually through distillation. But distillation requires energy. Which leads us to the biggest hurdle:

- Energy: any FT reaction is an endothermic reaction. Even low-temperature FT synthesis requires temperatures above 200°C, with high-temperature FT sometimes going up to 400 or even 600-700°C ranges. That means a LOT of heat which is usually obtained through burning natural gas. Simple thermodynamics will tell you that in practice, you will always need to invest more heat into making something than you can extract from it by breaking it apart. The energy required to maintain the heat for the FT reaction and the distillation of the products is far and away the biggest cost in the process.

 

In summary (TLDR):

- FT pocesses always produce a large fraction of waxy, long chain parafins. These are almost worthless from an economic standpoint, clog up your reactor something fierce and need to be distilled off. Cracking them and turning them into usable substances is not a bad idea and has been the subject of quite a lot of research already. Nothing I know of can do it selectively and cheaply enough though.

- FT processes and the distillation required afterwards require huge amounts of heat. Far more heat than the useful energy you can extract from your produced bydrocarbons by burning them. This is the big hurdle: if you can find a way to cleanly and cheaply produce energy, you can turn this process into an economically viable thing. However "cheap and clean energy" is basically the holy grail of energy production. If you find a way to do this, then you've basically solved the global warming problem as a whole. I believe this is also the big hidden cost you have not incorporated into your calculations. And that is not mentioning the heat it will require to extract CO2 and turn it into methane/syngas.

 

I do apologize if what I said has been discussed already, like I said, I haven't read the entire thread, but this topic of synthetic oil production is one that was very alive (and has been for years and years) in my faculty. I listed the two main arguments for why it doesn't work (yet) above. If economics change through scarcity of oil reserves and technological advancement in catalytic technology and energy production, then it could work. Just not yet.

Edited June 21, 2016 by Cirocco

[JebKeb]

I was thinking of using a slurry bed reactor to do the synthesis, so nothing would get clogged up.

Using a FCC would yield cracker naptha which you could use as a petrol blending stock. Any byproducts and other wax would be sent to a hydrocracker to be turned into light and heavy naptha, kerosene and gas oil.

From what I've seen (Sasol articles) the Fischer-Tropsch reaction actually appears to be a rather exothermic reaction. Still, the refining process takes energy. We should probably name it Power+air to fuel.

[Sereneti]

silly question but:
there are many , many exotermic reactions in this prozess...
maybee is it possible to recycle this energy?