Biofuel boilers (excluding solid fuels)

[David OLIVIER]

Does anyone know of any UK experience of burning fuels such as biodiesel (or related liquids) in small (preferably condensing) oil boilers?

A quick look on the web found only US websites, including a college in Vermont which is considering this.

I haven't yet asked the main manufacturers.

David.

[Chris Laughton]

See further one of the speakers on this subject at the Institute of Domestic Heating Engineer's conference.
www.idhee.org.uk

The Fielder Conference Centre,
University of Hertfordshire, Hatfield.

THURSDAY 17th MAY 2007

[David OLIVIER]

Chris

Thanks. IDHEE site says "experiments are underway" but couldn't find conference program.

R4 early this morning featured a dairy farm in Dorset building a methane digester of German design and program said that in Germany they would feed bio-methane into the gas grid, not generate electricity at 30-35% efficiency. Gas output of farm mentioned would be about 1000 kW.

David.

[Chris Laughton]

Try clicking on 'Conference' on left menu on the IDHEE website home page. In any case the the contact is for liquid Bio-Fuels for Central Heating is Andrew Robertson, MIDHEE Clean Energy Consultancy.

[Mark Siddall]

David
Try the Center for Renewable Energy from the Land (CREEL) at Newcastle University. They may be able to offer some insight.
(We are doing a project for them, though I am not sure how progressed they are with their current research programme.)

Mark

[Nigel Bishton]

You could try www.bioflam.com they claim to be able to convert oil boilers.

I am not convinced about the economics of biodiesel as I have been quoted 50p per litre for use as a heating fuel whereas heating oil is about 33p. I think biodiesel is best used for road transport.

[Nick Grant]

I agree Nigel, given that we don't have enough land to grow our transport fuel it seems crazy to heat homes with such high grade biofuel.

Palm oil fired Agas is where I see it heading.

[David OLIVIER]

Thanks.

Backup to solar in highly-efficient houses, not main heating fuel.

I've now found an article on the topic in Sustainable Building Feb 2007 by Andrew Robertson (author mentioned above by Chris). It has a major weakness though in that it does ignore energy efficiency, which could lead to just such a nightmare of large country houses with palm oil-fired Agas and Range Rovers. I don't want to see that either, but neither do I want to breathe their wood smoke.

Converting brand new boilers doesn't seem sensible so I hope some German or Austrian products will come onto the market which are already biodiesel-compatible. It appears that UK manfacturers except poss bioflam.com aren't interested (no change there, then).

David.

[Tahir]

Saw one designed to run on rapeseed at EcoBuild, built by Atlantic I believe. Huge big beasty.

[David OLIVIER]

Probably designed for the kind of house which also has an Aga and several Range Rovers!

D.

[Tahir]

Maybe, the smallest one produced 10kw I believe, went up to 200kw??

Good for a block of flats or other communal use maybe. They had the oil distribution network sorted apparently, deliveries of as little as 1000 litres, although 10,000 was the preferred drop.

[Roderick Williams]

Hi,

I'm building a low energy house in north Essex.  Originally I intended to use a solar combi system with a pellet boiler as backup.  But looking at the capital cost of the pellet boiler compared to the CH/DHW requirement its very difficult to justify.  So recently I started to look for liquid biofuel alternatives.

I looked for biodiesel into heating systems and found the work of Andrew Robertson:

http://www.biodiesel-expo.co.uk/download/4%20and%2010%20Robertson%20Biodiesel%20Expo%20Heating%20Seminar.pdf

As you can see from the paper he found that B20 was usable with a low cost (£200) adaption to a standard boiler but B50 and B100 had issues with low temperatures causing the fuel to become too viscous.
 
When I spoke to him on the phone his advice was that at present the biodiesel quality is quite variable and to fit a standard oil boiler now and then retrofit the adaption in a couple of years.

Via the forums at Navitron I found Atlantic's rape seed oil boilers.  Atlantic's boilers have particular design to ensure that they stay in condensing mode even when the return temp from the heating circuit is high.  I don't believe I need this if charging a thermal store.  The smallest boiler they do is 17kW that can be restricted to 10 kW.  They use a interchangeable burner design so its possible to swap burners for mineral oil to rape seed oil to gas.  The rape seed fuel is 45-55p/l and the boiler costs £2500.  They are bringing out a slightly more expensive burner this year that will burn all liquid oils provided the water content is below a certain level.  This could be interesting for burning waste vegetable oil directly, at 10p/l.  But this cost trade off would work best with a higher heat requirement. 

[Tahir]

Hi Roderick, interesting. I hope to be building a low energy house in South Essex...

[David OLIVIER]

10 kW is reasonable, most gas boilers are too large as well.

Thermal stores tend to need excessive temps. vs unvented cylinders.

If in north Essex have you met Mike Garnham? (Pebmarsh) He built two very low-energy houses, lives in one (thatched cottage aesthetics). Very low oil bill.

David

[Roderick Williams]

Tahir: good luck with the build, if you want to compare notes you are more than welcome to come and have a look at the build so far.  The frame is 2/3 complete built with masonite beams.  The builder I'm using is Wilkinson Builders, I came across them when looking for airtight buildings in Masonite. So far their attention to detail has been very good, but the airtest will give the final verdict.  The windows from Thermotech and should be fitted in about a month.  I'm just finalising the solar combi, biofuel boiler and WHV with heat battery.   

David:  Is the reason that thermal stores require a higher temperature because they use an indirect heating element rather than heating the contents of a pressurised store directly?  Should a condensing boiler be able to load either vented or unvented and stay in condensing mode? The choice between vented and unvented store will probably be dictated by the solar combi system I can fit.  I intended to use a Consolar unit but couldn't find a Consolar trained fitter who would install in my area, as a result I'm probably going to use Sonnenkraft.

I've not come across Mike Garnham, does he specialise in heating or is he a general builder?

Rod