Synthetic Hydrocarbons

[wacki]

With all the talk about Hydrogen cars, I've decided to do some research. It seems that a lot of scientists think that synthetic hydrocarbons are the way to go. And these links explain why in simple english:

http://www.eurekalert.org/pub_releases/2005-03/nu-nfc033105.php
http://www.idatech.com/technology/publications.html?pub=14
http://www.hydrogennews.org/hydrogen/

Nice charts here showing the weakness behing Hydrogen cars:
http://www.methanol.org/pdf/HydrogenEconomyReport2003.pdf

My question is, how hard is it to make synthetic hydrogen? Obviously there is methanol from biomass by these guys are talking about recycling CO2 from the atmosphere. How do you do that?

 

[Calin]

Hydrogen powered cars carry much less fuel than the typical gasoline or diesel car (one of the current prototypes - a Ford Focus CMAX has 200km autonomy). Compare this to 1000km for many cars now on the roads. Also, my car has a fuel tank of 70l, and at highway uses some 7l at 100 km. The CMax has three hydrogen tanks totalling 200+ liters.
Brasilian cars use (instead of gasoline) some alcohol (methanol or ethanol or something) distilled from plants. It is somewhat similar to gasoline in regards as power per engine displacement or fuel efficiency (miles per gallon), muh better than hydrogen.
The problem is: would you drive a car that needs to be refuleled every hundred miles? I don't think I would

 

[MobiusPizza]

What they meant is relatively simple process.

Plants capture carbon dioxide in air and make sugar everyone knows that. Even with human's technology we cannot minmic how plants do that currently. So we have to rely on plants. Then we fermmentate plants with rich in sugar content (e.g. sugar cane) with bacteria culture (similar to how they make beer) to obtain ethanol. This can be done industrially in large scale. Though it is a batch process, not a real-time process.

It is how Brazil (currently biggest use of renewable-fuel in cars) 's sythesized alcohol for car engine is made, using sugar canes and fermentate them. This way generating fuel from biomass is considered a renewable resource.

 

[Calin]

There is another way for renewable fuel - biodiesel. Cultivating plants rich in oil, and use the oil to fuel diesel cars (there must be some changes made, like better filtration and heated conducts for the oil, as cold oil isn't flowing enough. The kit to "upgrade" diesel engines runs at around 2000 dollars (there is a cheaper kit for running the engine on biodiesel only when hot, starting and stopping are done on normal diesel fuel

 

[CycloWizard]

Originally posted by: AnnihilatorX
What they meant is relatively simple process.

Plants capture carbon dioxide in air and make sugar everyone knows that. Even with human's technology we cannot minmic how plants do that currently. So we have to rely on plants. Then we fermmentate plants with rich in sugar content (e.g. sugar cane) with bacteria culture (similar to how they make beer) to obtain ethanol. This can be done industrially in large scale. Though it is a batch process, not a real-time process.

It is how Brazil (currently biggest use of renewable-fuel in cars) 's sythesized alcohol for car engine is made, using sugar canes and fermentate them. This way generating fuel from biomass is considered a renewable resource.

:thumbsup:

Making these processes continuous and automated is no trivial task. I sat in on a PhD thesis defense yesterday discussing how to do this with a similar process. The technology is coming, but it'll still be a while. Once they are made continuous, then everything becomes much cheaper and easier. Running things in batch inherently limits the production quantities, since you have to manually move things around and such.

 

[wacki]

Originally posted by: Calin
Hydrogen powered cars carry much less fuel than the typical gasoline or diesel car (one of the current prototypes - a Ford Focus CMAX has 200km autonomy). Compare this to 1000km for many cars now on the roads. Also, my car has a fuel tank of 70l, and at highway uses some 7l at 100 km. The CMax has three hydrogen tanks totalling 200+ liters.
Brasilian cars use (instead of gasoline) some alcohol (methanol or ethanol or something) distilled from plants. It is somewhat similar to gasoline in regards as power per engine displacement or fuel efficiency (miles per gallon), muh better than hydrogen.
The problem is: would you drive a car that needs to be refuleled every hundred miles? I don't think I would

I know this. My question is how do you create synthetic hydrocarbons. What are the current technologies and what technologies might be possible in the future.

My question isn't about hydrogen cars at all. Hydrogen is a bad technology IMO.

 

[MobiusPizza]

Yeah Calin. The point he made is about a possible solution to store and transport hydrogen so that cars might be able to store more hydrogen with lighter cartridges and consquently be able to run longer.

 

[wacki]

Originally posted by: AnnihilatorX
Yeah Calin. The point he made is about a possible solution to store and transport hydrogen so that cars might be able to store more hydrogen with lighter cartridges and consquently be able to run longer.

No, my question is, how do you create synthetic hydrocarbons.

In plain english, how do you create artificial gasoline?

Hydrogen is not a good technology. The best cartridge for hydrogen is zeolite. Even with zeolite, performance is mediocre at best. Forget hydrogen, I'm talking about synthetic gasoline, synthetic ethanol, synthetic methanol.

 

[The Boston Dangler]

I believe George Washington Carver made a biodiesel from corn or peanuts. That was at least 40 years ago.

 

[Calin]

Sorry for derailling the topic. How do you make synthetic gasoline?
1. You start with a heavy fraction (heavy fuel) and heat it real good (like 600Celsius or more). It will go thru a process of "cracking" and the result will be a lighter fraction (gasoline) and coals (well, carbons) and/or very heavy fuels like fuel oil and/or something asphaltic (bitumen).

 

[Calin]

Another way is explained here:
gasoline from hydrogen and coal

If you inject vaporized water on very hot coal, the coal will "capture" the oxygen from the water and the result is free hydrogen (I mean H2, not linked hydrogen like in water) and carbon monoxyde. Those gasses are then catalitically converted to methanol (methilic alcohol, which is bad for your health, unlike the ethilic alcohol which is good for your health).
The methanol is then forced thru other catallitic converters, and in the end high octane fuel results (and some byproducts).

 

[MobiusPizza]

Originally posted by: wacki

Originally posted by: AnnihilatorX
Yeah Calin. The point he made is about a possible solution to store and transport hydrogen so that cars might be able to store more hydrogen with lighter cartridges and consquently be able to run longer.

No, my question is, how do you create synthetic hydrocarbons.

In plain english, how do you create artificial gasoline?

Hydrogen is not a good technology. The best cartridge for hydrogen is zeolite. Even with zeolite, performance is mediocre at best. Forget hydrogen, I'm talking about synthetic gasoline, synthetic ethanol, synthetic methanol.

On the 3rd investigation they investigate whether sythetic fuel can be used as a storage medium for hydrogen. Hydrogen is not a bad thing IF the storage problem is solved.

 

[Calin]

Synthetic methanol and fuel cells could be a solution - just that methanol is not a hydrocarbon, it also contains oxygen

 

[Lynx516]

To make totaly synthetic hydrocarbons you would need to make methane out of something (cannot remember how) and then add carbons to the chain. The main problem would be if you want an arene ring then I am not sure. Basically everything is possible the main problems is the yeilds.

 

[DrPizza]

Originally posted by: Lynx516
To make totaly synthetic hydrocarbons you would need to make methane out of something (cannot remember how) and then add carbons to the chain. The main problem would be if you want an arene ring then I am not sure. Basically everything is possible the main problems is the yeilds.

You're giving me nightmares recalling organic chem.
All the tests started the same way:
"you're on a desert island with an abundant supply of grapes. Fortunately for you, a raft floats up filled with lab equipment and all the reagents you could ever ask for. Starting with ethanol which you obtained from fermenting the grapes, synthesize the following compounds:
1. The chemical that killed 800 people in Bhopal, India 3 days ago.
2. 2,4 dimethyl . . ."

I'll never forget the question about Bhopal, India... an organic chem professor who managed to put current events on a chemistry test.

 

[Gibsons]

Originally posted by: DrPizza

Originally posted by: Lynx516
To make totaly synthetic hydrocarbons you would need to make methane out of something (cannot remember how) and then add carbons to the chain. The main problem would be if you want an arene ring then I am not sure. Basically everything is possible the main problems is the yeilds.

You're giving me nightmares recalling organic chem.
All the tests started the same way:
"you're on a desert island with an abundant supply of grapes. Fortunately for you, a raft floats up filled with lab equipment and all the reagents you could ever ask for. Starting with ethanol which you obtained from fermenting the grapes, synthesize the following compounds:
1. The chemical that killed 800 people in Bhopal, India 3 days ago.
2. 2,4 dimethyl . . ."

I'll never forget the question about Bhopal, India... an organic chem professor who managed to put current events on a chemistry test.

hm, methylisothiocyanate, CH3NCS "obtained by the action of CS2 on methylamine." - Merck manual.

That's as far as I got, glad I'm not being graded.

As for the original question, what's needed is a reaction process that does

CO2 + 2H2O -> CH4 + 2O2

Obviously, such a reaction would be very energy intensive and would have to occur at low temepratures to prevent combustion of the end products.

Plants/chlorophyl comes close to this, but the end product is C6H12O6 (sugar). Using yeast to further convert the sugar to ethanol seems wasteful, but we don't have an alternative at the moment.

 

[JonB]

Lots of mentions of yeast and sugar, but most biomass is high in starch and non-digestible fiber, not sugar. Starch must first be converted to sugar (fructose, mainly) before yeast can get to work. Given a long enough fermentation system, it could be continuous. Yeast would need to be in contact with the sugar for at least three days to get a good conversion. At different points, yeast needs oxygen to reproduce, then no oxygen for maximum ethanol production. The ethanol will be high quality fuel and is easily removed by distillation. The remaining, undigested slurry can be dried and returned to the cycle as fertilizer.

:beer: :beer: :beer: :beer: :beer: :beer: :beer: :beer: