John – Wood oil was put forward for use in combustion engines but I understand solids content plus low ph and high sg creates problems, wood gas appears to offer hope if it can be produced economically with suitable characteristics.
Your suggestions of filter applications although effective incur substantial cost which unfortunately means they are avoided in the UK where the combustion industry appear to exploit loose regulation e.g. current biomass plant proposal detailing use of multi- cyclone filter system despite knowledge that it is ineffective in removal of sub PM 10 particles. The irony is there are reports that we are exporting WESP systems for effective PM abatement on biomass combustion plants in other Countries.
A few years ago I noted reports of Swiss success in use of ceramic filters and suggested use in the UK to the Environment Agency but the response was ceramic filters were considered unsuitable due to failure caused by thermal shock. Based on experience with ceramics in heating considered it rubbish and now note ceramic filters are being retrospectively fitted to Scottish biomass installations at schools and public premises.
Other Countries are taking positive action in order to reduce nasties such as PM, NOX and SO2 pollution and protect life , we appear to fixate on carbon and ignore the deliberate degradation of our air quality. This is despite our knowledge of external cost implications resulting from the damage.

6 more posts and it'll hit a 1000 , do i get a price

http://www.bbc.co.uk/news/science-environment-20303668
Includes-
“Drax will get 10% of its fuel from British sources like these and there's a high-walled maze at the power station of blocks of chopped miscanthus next to high mounds of shredded willow.
But since energy crops first stirred agricultural excitement there's been controversy over the impact of using land to grow crops to burn. Drax say miscanthus can still be useful for farmers wanting to stabilise sandy soils.
But it is possible that in future this may be uneconomic, and that growing coppiced wood for burning will be mainly concentrated on the high-value market for wood-burning stoves in the homes of the rich.
In the meantime, the imports of wood from round the world are likely to continue”
90% import requirement, price of indigenous biomass such as miscanthus doubled, confirmed degradation of air quality compared with fossil fuel , low efficiency biomass powerplants in UK with high pollution burden per unit of useful power out. Where is the due diligence and joined up thinking?
“high- value market for wood-burning stoves in the homes of the rich” ! So what should be the real future for wood burning in the UK and the consequences?
Rgds Brian Wilson

The only reason that it would be small is because it is a minority sport.

In therms of per unit it is worse than average. and average is already way too bad.

1000!

Do I win the prize?

BTW, nothing helpful to add to the debate, other than I have been looking at smoking chimneys differently in the last few weeks now the weather has turned. Fine for the minority, not for the majority. I was in London today, and I was thinking (while I was driving around) that if all the chimneys on the houses were producing emissions from open fires or wood stoves, we would be in serious trouble!

I think the future will include domestic-size woodburners far more sophisticated than the crude boxes they mostly are at present. It'll cost, but then what won't?

Technology is already on its way. Efficiencies in excess of 5x chemical energy of wood are already achievable and does not rely on burning wood.

No just good old fashioned friction

Posted By: renewablejohnTechnology is already on its way. Efficiencies in excess of 5x chemical energy of wood are already achievable and does not rely on burning wood.

Depending on the way it is measured it could be PV as that has a yield of about that per metre squared

What is the 'brake block' rubbing against?

Stolen my thunder Bill

Posted By: SteamyTeaTimber
How is your stove design doing, has it smoked out my parents yet, not heard from them is a week or twohttps:///newforum/extensions/Vanillacons/smilies/standard/bigsmile.gif" alt="" title="" >

Nah, it is going well. Ironically though given my comments about chimneys and smoke etc.

In my defense, it is much better than an open fire that many people run, and once running it doesn't emit any visible smoke from the chimney, which I am happy about.

Basic physical law is that you cant extract more energy from a system that went into it (except fission and fusion and snake oil)

Free energy is an interesting concept though

Posted By: tonyBasic physical law is that you cant extract more energy from a system that went into it (except fission and fusion and snake oil)

Free energy is an interesting concept though

Where not talking overunity. The wood is being consumed as a fuel only the heat output is greater than its chemical composition. No different analogy to a heat pump having a COP in excess of 1 or is that snake oil as well.

Posted By: renewablejohnNo different analogy to a heat pump having a COP in excess of 1 or is that snake oil as well.

That is not how a heat pump works.

So you have a wheel/disk/shaft and a friction surface (your wooden block), as you spin the wheel, the blocks get hot. You then draw the heat away (probably though pipes and a fluid) and do something with that energy.
Now that wheel takes energy to turn it, takes even more with it has a brake on it. So you get the energy for 'free', say a turbine of some sort (though you could push a truck down a hill, but would have to push it up again), the formula for calculating the energy in the wind/water is well know and can give you the input energy. The change in energy caused by the rise in temperature of the brake blocks can be measures and the energy calculated.
Bet it is not more than than energy input. In fact I know it will not be.
Now what you are actually talking about here is energy harvesting from low entropy sources. Not the same as over unity though.
The thing to remember is that you have to calculate all the inputs but only one output (the useful bit) to calculate the efficiency.
So you have been measuring the wrong thing.

Steamy

I suggest you look up friction on Wicki then you might have a better understanding

What you fail to grasp is the friction wood blocks are actually a fuel source just the same as petrol in a combustion engine.