Electricity from wood?

[chilled_fluorine]

There was just a storm here, and I have access to hundreds, more likely thousands of kilos of wood. Is there any way I could use it to make electricity? No, I don't have a sterling engine. Anyways, should I sell it as firewood and use the money to buy petrol for my car, from which I will get electricity? Or could I make some epic carbon-air fuel cell, if such a thing is possible? Doesn't seem too likely that it is, but you have to assume an idea could potentially work, if not, we wouldn't have a chance of inventing anything new... The wood would probably need pyrolysis for purification if it was... Any ideas people?

[Phi for All]

Wood gasification.

[chilled_fluorine]

Wood gasification.

 

I don't think your link said how to make wood gas, but it sounds like you could be on to something. Once I had the gas, would I just use a standard hydrogen fuel cell? What about all the CO? Could the fuel cell finish burning that?

[CaptainPanic]

I don't think your link said how to make wood gas, but it sounds like you could be on to something. Once I had the gas, would I just use a standard hydrogen fuel cell? What about all the CO? Could the fuel cell finish burning that?

I think the most popular way is to:

 

1. Make gas by gasification

2. Clean the gas

3. Put that into an engine

4. Connect that to an alternator

 

The gas cleaning is not the easiest, but depending on the engine might be totally necessary. The gas you make will contain small particles (bit like soot), heavy tars, carbon monoxide, hydrogen, CO2, water, methane, and loads of other components. If you have a robust engine, you can put it in directly... but your neighbors might not like the type of smoke that comes out the exhaust. But typically, modern engines are too finely tuned to run well with such a gas.

 

The gas you get from gasification is far too dirty to put into a fuel cell.

 

To be honest, you're best bet is to sell the wood as firewood.

[alpha2cen]

Once I had the gas, would I just use a standard hydrogen fuel cell? What about all the CO? Could the fuel cell finish burning that?

 

on the catalyst CO + H2O --> CO2 + H2

and separate H2 from the other gas using membrane or so

H2--->fuel cell

and not reacted CO + O2---> CO2 reaction occurs on the oxidation catalyst.

 

Current fuel cell is operated at the high temperature.

But, high temperature resisting material and electrolyte solution are difficult parts to make.

Edited August 24, 2012 by alpha2cen

[CaptainPanic]

on the catalyst CO + H2O --> CO2 + H2

It's CO + H2O <--> CO2 + H2

It is called the water gas shift reaction, and it is an equilibrium. To get complete conversion to H2, you need a separation and a recycle.

 

But because your gasification gas is (as I said before) full of other molecules, you will need more (many more) separations before you can send the gas to a fuel cell.

 

And then there is that little issue that a fuel cell is just not a very economical thing.

[John Cuthber]

I wonder if any of these ideas will be more efficient than burn the wood, use it to run a steam engine and use that to run a generator.

Somehow I doubt it.

[Phi for All]

I wonder if any of these ideas will be more efficient than burn the wood, use it to run a steam engine and use that to run a generator.

Somehow I doubt it.

I thought of that first, tbh, but was a bit leery of someone making a steam engine. Of the two methods, the steam engine seemed the most dangerous for a do-it-yourselfer.

[Greg H.]

I wonder if any of these ideas will be more efficient than burn the wood, use it to run a steam engine and use that to run a generator.

Somehow I doubt it.

 

You could, in theory at least, burn the wood in the presence of a thermopile and produce electricity directly, but I have no idea how efficient that would be.

 

I thought of that first, tbh, but was a bit leery of someone making a steam engine. Of the two methods, the steam engine seemed the most dangerous for a do-it-yourselfer.

 

Steam engines are definitely on the dangerous side. A boiler explosion can seriously ruin your day.

[Phi for All]

Steam engines are definitely on the dangerous side. A boiler explosion can seriously ruin your day.

I suppose if you went with a simple classic design, and hooked it up to a generator, you could minimize the danger of high-pressure steam. I wonder if something along these lines would work:

 

 

Replacing the Sterno with a wood fire, of course.

[Greg H.]

I suppose if you went with a simple classic design, and hooked it up to a generator, you could minimize the danger of high-pressure steam. I wonder if something along these lines would work:

 

 

Replacing the Sterno with a wood fire, of course.

 

I am guessing it would work, but the efficiency with steam power is typically related to the pressure of the steam. You could experiment with smaller nozzles I suppose, and see what gives you the best work output, then thread the whole thing into a generator directly. I'd be curious to know how much steam pressure it would take to turn the generator.

[JMJones0424]

With that design, it seems to me that once you put any kind of load on it, the steam (or hot gases) would tend to just escape around the upturned can rather than pressurize the can and flow out the nozzles. In essence, what you are creating is a rotating chimney flue with far too much constriction and a massive amount of leakage right around the source.

 

I don't know where you live chilled or the quality of the wood, but if you're looking for an economically beneficial way of disposing of the wood, I'd consider the following after judging the local marketplace:

1) Firewood

2) Processed products like lump char, dimensional lumber, feedstock for woodcrafts, etc.

3) Direct use of heat from combustion using a rocket stove mass heater, outdoor oven, or similar device.

 

Do you have a garden?

 

If you're in it for the joy of tinkering rather than for economical reasons, then it's a completely different matter.

[Phi for All]

Do you have a garden?

Another good idea, in a more commercial, non-chemical way. Depending on the type of wood, I might rent a chipper and reduce the thousands of kilos of wood to wood chips, load them in my truck and make the rounds in upscale neighborhoods offering to replenish people's gardens or landscaping. Chippers have their own danger, in a Fargo kind of way, but are more reliable than homemade boilers.

[John Cuthber]

I thought of that first, tbh, but was a bit leery of someone making a steam engine. Of the two methods, the steam engine seemed the most dangerous for a do-it-yourselfer.

I had the idea in mind that someone might (boringly) buy a steam engine.

Making your own would be risky.

[chilled_fluorine]

With that design, it seems to me that once you put any kind of load on it, the steam (or hot gases) would tend to just escape around the upturned can rather than pressurize the can and flow out the nozzles. In essence, what you are creating is a rotating chimney flue with far too much constriction and a massive amount of leakage right around the source.

 

I don't know where you live chilled or the quality of the wood, but if you're looking for an economically beneficial way of disposing of the wood, I'd consider the following after judging the local marketplace:

1) Firewood

2) Processed products like lump char, dimensional lumber, feedstock for woodcrafts, etc.

3) Direct use of heat from combustion using a rocket stove mass heater, outdoor oven, or similar device.

 

Do you have a garden?

 

If you're in it for the joy of tinkering rather than for economical reasons, then it's a completely different matter.

JM, thank you. Right now I would guesstimate I have 4000 kg of nice, dense oak wood stockpiled in my backyard. Although people often think I am from the uk because I am "too eloquent to be one of those dumb Americans", I do in fact live in the USA, and I really don't think I'm all that eloquent. Anyways, I do have a garden, it is the pride of my neighbourhood, but how is that at all relevant? If I wanted to tinker, I am sure there would be better things to do with my time. I am trying to live a more symbiotic life, and to leave as small a footprint as possible. Sounds futile, I know, and that's because it is. But it makes me feel better about humanities hopeless situation. Just remember, my desired product is electricity. I want electricity, with as little effort as possible, and in reasonably large quantities, and for free. This must sound very demanding, but I am providing chemical energy, so why not? Seems like my best option is selling it as firewood.