Cornwall is full, honest, it really is, no green spaces here. There will be plenty of space in August for a couple of weeks though, you will have to bring your own caravan though and plenty of cash, we like cash down here still.

Brian, What are the typical particulate emissions from say,a 40KW log gasification boiler. Would it be not quite as clean as pellets?

Brian, Do you have any data on the new-fangled method of gasification known as Plasma Gasification - whereby molecules are shot to pieces at several thousand degrees by a plasma arc. The resulting syngases are then combusted for heat, power or both - obviously power must be provided for the arc/torch to set the whole process going although this can be derived from the syngas combustion itself. I guess the impurities from the material can be separated and not emitted with only C0 H2 and traces of CH4 burnt.

A topical news item from the other end of the UK:

http://www.businessgreen.com/business-green/news/2272826/biomass-fuelled-ports-woo

Rgds

Damon

DamonHD- Interesting proposal for Forth ports. Quick perusal of data details 200MW plant stated feedstock requirement 900,000 tonnes. We know a 300MW plant requires 2.4million tonnes plus depending on moisture content so on that basis this plant needs 1.6 million tonnes. Based on stated requirement detailed for Stevens Croft biomass plant the figure rises above 2m tonnes.We are again into the biomass plant operators land of myths and spin.
Our current understanding is some 50 million tonnes will need to be imported annually mainly from the Americas.
Again can only hope joined up thinking and due diligence will play a part in any decisions not just financial greed.

Looking at the Department of Energy website. 2009 coal supply was around 48 million tonnes with imports at 38 million tonnes. About 40 million used for electricity generation. Importing 50 million tonnes of wood makes no sense.

A presentation about Plasma Gasification

http://www.dovetailinc.org/files/u1/PlasmaGasificationPresentation.pdf

Looks a lot better than incineration but high capital costs have so far limited its appeal.

Brian: at a pinch transmission losses from Scotland to England could be lower than the energy costs of transport to an English harbour and combustion plant, just for example, for various reasons. Actually I think the biggest flows in the UK are from the north to the south of England rather than between Scotland and England, but I can't find the data right now.

Rgds

Damon

What happens when the wind is blowing from the North and East?

Brian
Have you been learning your cynicism from

Brian
I am totally with you there, air pollution is a serious problem and not just from human health point of view. More particulates also affect the amount of solar radiation and precipitation which affect plant growth. Currently working on the variation in solar forcing caused by cloud cover and may well be able to use the same model to find a weather signal 'downwind' of urban areas.

Not so sure about this NNE wind being 'good', it must have blown across the whole country before getting here. As it is currently blowing at nearly 30mph that means it has had about 20 hours to pick everything up.

On a more serious note, what would be the best technology to use in a small domestic wood burner to reduce particulates. My father was involved in writing up a treatise for fluidised bed coal combustion in the 50's or 60's, not really practical for domestic use I know but is increasing the surface area of the combustion material generally the best way to go?

On a more serious note, what would be the best technology to use in a small domestic wood burner to reduce particulates.

How about an electrostatic precipitator, and a catalytic converter? Some of the big log burners already have an oxygen sensor.
Or some sort of water washing of the flue gas?

evan- I must bow to your knowledge on local power requirements but would be surprised if 200MW of additional capacity is needed and can be absorbed. My concern is the pollution burden that comes with biomass combustion. Scotland has great potential for clean renewables which surely should be the priority.
Reference transmission losses they do tend to be significant when using AC transmission which is why tariffs are loaded against remoter locations.
Joiner- re particulate filters for domestic use I understand there is urgent ongoing research being carried out in Scandinavian regions but not seen any results. It would appear current favourite is ceramic filters but problems is cost in domestic applications. One fundamental problem with filters is high maintenance input reqd. I note particulate issue is a serious problem in Scandinavia with woodburners reported to create more than 80% of winter particulates.

Steamy Tea- Interesting point on cloud impact, biomass combustion produces large quantities of water( confirmed toxic) this raises questions of possible micro-climate downwind of these large plants. Green timber is known to be 50-60% water, sewage sludge (also classed as biomass) is 95% water. I recently raised concern regarding project specified to burn 90,000 tonnes of contaminated timber plus 46,000 tonnes of sewage sludge per year. Feedstock specified to create 40 million litres of toxic and acidic water to fall where? Overall moisture content to form 19% of emissions.The plant to be positioned in middle of the most fertile land in UK producing some 20% of UK veg. The emissions impact assurances for this "novel" project is provided by computer modelling. One fundamental concern is sulphur dioxide burden per unit of power produced is specified to be 98 times higher than equivalent fossil fuel.
Thankfully whichever way the wind blows you should be subject to minimum impact from major burning proposals, I understand fine particles tend to remain in suspension for up to 200km, larger particles return to earth much earlier.

joiner- point taken, I made comment based on fluestack emissions with limited thermal boyancy but there are of course many variables that can be included to impact on prediction of particulate travels. Your comment does move us into impact of contrails!

DamonHD- Damon I understand transmission losses are detailed to be between 7.4 and 12% and flow requirement Nth to Sth UK is 11GW and rising. This would point to definite advantages in building powerplants in the Sth close to load centres. There are obvious physical problems in providing berthing facilities for low energy density fuel transportation but there are alternative fuels. It would appear a further 8% loss will be incurred in bringing power from Northern Scotland.
Rgds
brian