Production of Ethanol/Methanol from Air and Water

[PraAnan]

Hi,
I'm a secondary school student from India and I am currently doing a group project to develop an 'eco-town' as part of an assignment. While others are working on the different aspects that need to be looked at I am looking for a way to keep the town moving by using green fuel. We decided to use ethanol/methanol as fuel for our project and I have to come up with a efficient and economical way to produce the fuel.

I estimated that we need 10 million liters of fuel per year for the town so I'm looking for some technology (old or new) which I could write about. I have already sent a couple of e-mails but people either never reply or they don't seem to want to help.

I know that methanol can technically be made out of water, air and electricity and it would be pretty cool to write about making fuel from air. An idea I keep coming back to is to use renewable energy such as solar (it's very sunny here), wind, hydro and even to some extent nuclear (or waste energy from power plants) and have a plant which produces methanol from waste CO2 and hydrogen (maybe from this).

Price of the fuel and plant is one of the more important things and they have to be as low as possible.

As a side question does anyone know how much ethanol/methanol fuel costs per liter in bulk? because if the price can be bought low enough that would make my work much easier as then I could just import it into the town.

Hope you can help.


As for if this is the right section of the forum to post this in, I initially wanted to post it in the homework section but I thought I would get more answers in the chemical engineering section (even though a part of me wanted to post in the chemistry section).

 

[HighDesert]

Hi PraAnan,

Those are some good ideas you have. I like to see young people thinking about solutions to global problems we face. Your idea about producing alcohols from waste streams is good, but your overlooking one very important fact: it costs energy to make them. You have to generate energy to manufacture the photoelectric cells, to pump the waste streams to your plant, not to mention the energy required to perform the reaction from CO₂ and hydrogen to methanol. I'll leave the number crunching up to you, but I'll bet that it will cost you more energy to make the fuel than the actual energy you will get from the fuel itself to move cars around. At that point, why don't you just have battery powered cars in your city and use all the energy you'd be producing to charge the batteries?

If you want to use liquid transportation fuels rather than batteries, you should take a look at biofuels from algae or some other active areas of biofuels research to give you some ideas.

 

[pantaz]

... As a side question does anyone know how much ethanol/methanol fuel costs per liter in bulk? ...

That's going to depend on many factors specific to the locale. You will need to check with existing suppliers to get an idea of costs in your area.

 

[Bobbywhy]

PraAnan, Welcome to Physics Forums!
When we want to produce “green” fuel it is useful to first look around and learn what others are doing. Here are three websites that may give you some ideas:

http://en.wikipedia.org/wiki/Ethanol_fuel
http://en.wikipedia.org/wiki/Ethanol_fuel_in_Brazil
Biodiesel from Sugar Cane
http://energyoutlook.blogspot.com/2009/07/biodiesel-from-sugar-cane.html

 

[PraAnan]

I really would like a way which doesn't use a land based feedstock like sugarcane or corn as the footprint of the entire plant needs to be under 1 square kilometer (247 acres). The only thing that comes close to this is fuel from algae but the people I've tried to contact about that area of research still haven't got back to me which is why I came to my fuel from electricity idea.

It would be nice if someone could actually outline the process of methanol production using energy.

Would it be possible to reverse a methanol fuel cell so instead of the output being water, CO2 and electricty; it would be methanol?

As for where the energy for this will come from, the excess electricity from the plant which powers the town will go towards making the fuel (such as from off-peak times).

 

[PraAnan]

Can no one tell me about how methanol could be made if you had access to water, air and electricity?

 

[Bobbywhy]

PraAnan, your request for a method to produce methanol from water, air, and electricity is not answerable because it cannot be done. Methanol is a chemical with the formula CH3OH. Those compounds are not present in water and air.

To make methanol, you need first to create synthesis gas, which has carbon monoxide and hydrogen gas as its main components. While natural gas is most often used in the global economy, methanol has the distinct advantage of 'polygeneration' - whereby methanol can be made from any resource that can be converted first into synthesis gas. Through gasification, synthesis gas can be produced from anything that is or ever was a plant. This includes biomass, agricultural and timber waste, solid municipal waste, and a number of other feedstocks.

Using Google to search for "methanol production" I discovered that a few bacteria such as pectinolytic strains of Clostridium butyricum, Erwinia, and Pseudomonas species produced methanol as a major end product during growth on pectin.

Cheers,
Bobbywhy

 

[chemisttree]

Methanol can be made from CO2 by a roundabout process. The most common process involves the combination of carbon monoxide and hydrogen over an copper/zinc/alumina catalyst. Hydrogen and carbon monoxide are derived from methane via the water gas shift reaction and methane is usually produced by separation from natural gas. That is the non-green part to the process and it's cheap because natural gas is fairly cheap. If you want to produce methane from electricity and CO2... it has been done but it is still a bit experimental.

You will need hydrogen as well as carbon monoxide for the ICI process. Hydrogen can be made by electrolyzing water and so you could get that part of your process in a fairly green way. There is a new process that we were discussing over in the Chemistry Forum. Very interesting. Of course you would also need CO as well. There has been some work http://www.technologyreview.com/news/409206/turning-carbon-dioxide-into-fuel/ but at what price? These processes need a pure stream of carbon dioxide to operate efficiently and the cost of isolating and purifying carbon dioxide makes these processes wickedly expensive. Your choice to use ethanol or methanol is problematic but not impossible. Very unlikely you will get anything near to 'efficient and economical' though.

Why not run everything directly from solar energy? Things would be electric rather than fuel-based and your goal of 'efficient and economical' would not seem that far fetched.

If there were truly a way to efficiently and economically manufacture methanol or ethanol without using a large amount of agricultural materials, I would never tell anyone how I did it until you all started writing checks to me!

 

[PraAnan]

Bobbywhy, I asked about making methanol from CO2 because a chemist that I initially sent a message to said that it was possible but now I think that he got mixed up between dioxide and monoxide.

This company seems to be basically doing what I'd like to write about in my project but after sending them a couple of messages they still haven't replied to me.
This is an interesting article and the section about Liquid Light piqued my interest but again, no reply from them as well.

chemisttree, it's interesting that you brought up the production of methane because we were talking about getting methane from biogas plants using human excrement and the person working on sanitation wanted to ask if it would be possible to build a household biogas plant which could provide enough methane for the cooking needs of a family of 4-5 people.

That artificial leaf is pretty amazing.

Well if you ever find a way to do it send me a message, I have a couple thousand rupees which I could send your way .

 

[PraAnan]

Could someone help me with getting a scientific paper from sciencedirect.com?

There is an article I would like to read but to view the full version I need to pay $31.50 which for me is quite a bit of money so I was wondering if someone who has an account with them could help me.

 

[Bobbywhy]

Please post the paper's title and author(s) and, the name of the publication. Thank you.

 

[PraAnan]

Bobbywhy, this is the link to the page:
http://www.sciencedirect.com/science/article/pii/S0360319999000087

Out of curiosity, why are they asking for so much for a scientific paper especially in the off-chance that it might not be helpful? If you're a professor or student at an university do they offer big discounts or something?

 

[PraAnan]

Just one last bump to see if someone can help me get the research paper.

 

[Alkim]

PraAnan,

Using electricity for generating fuels is not a very good idea since in this way you have at least three efficiency-limited steps: generation of electricity - synthesis of fuel - burning of the fuel to transform it to other types of energy. Electricity itself is good enough as a driving force, but if you need to heat/cool you can use directly sun, wind and geothermal energy and generate electricity only for driving mechanical devices and for storing energy for the periods when there is no sun/wind.

 

[theban]

Out of curiosity, why are they asking for so much for a scientific paper especially in the off-chance that it might not be helpful? If you're a professor or student at an university do they offer big discounts or something?

Universities usually have a deal with these online journals - the professors and students pay nothing. Great if you're currently with a university, pretty bad if you're not. Fortunately, the journals don't (to my knowledge) have exclusive rights to a paper, so you can find them elsewhere. Google Scholar is a good start: http://scholar.google.com/

 

[Graniar]

Wow! One of my favorite, sun power station in desert, which produces methanol from air.

The best would be to use H2O photolisys to produce H2, but indirect electrolisys is good as well.

Water and CO2 may be obtained right from the air. A bit expensive, but uncomparable for total energy consumption.

Methanol may be acquired through reacton 2H2 + CO2 <=> CH3OH <=> 2H2O + CO

 

[BobbyT]

Hopefully this is not too late of a post to your query, there have been developments of late from British researchers on producing methanol then converting it to petroleum and a firm in Silicon Valley producing methanol and then petroleum using a ceramic catalyst, CO2 from air, water and electricity to produce fuels. I've included a link to an article in The Telegraph http://www.telegraph.co.uk/earth/energy/fuel/9619269/British-engineers-produce-amazing-petrol-from-air-technology.html
The Silicon Valley firm is very secretive at present but you should be able to find more data by looking at their patents.

 

[pikpobedy]

Not for methanol but for methane:
The making of CH4 from CO2, H20 and sunlight is the basic premise for the Mars to Earth return trip.
http://www.nature.com/news/2009/090205/full/news.2009.83.html