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Biodiesel?


simonr

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I had an interesting chat today with a company selling kits to allow diesel engines to run off ordinary cooking oil (not biodiesel at all).

The kit comprises a second tank (for the oil), a heater / heat exchanger (to lower its viscosity) a change-over valve, a purge valve & pump (to switch back to ordinary diesel quickly), filters, hoses & wiring.

It is designed to work with either reclaimed oil which has been filtered and treated with methanol or plain cooking oil from supermarkets etc. He says that you can buy oil from Asda for about 45p a litre and if you go to an oil miller, less than 25p.

I wondered what level of interest there would be in such conversion kits being available specifically for Land Rovers (with the correct fittings etc) and whether it would be worth colaborating with them to develop one?

I was thinking about buying one for my SV (me being a lot poorer now!) but wondered if you lot had any opinions of this as a concept or even direct experience.

The payback time, even if you pay the duty at 27p per litre, seems to be in the order of a year (based on 28mpg and 10k per year).

Until today, I was a bit confused by all the options - but this does seem to make it simple!

Si

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allow diesel engines to run off ordinary cooking oil (not biodiesel at all).

The kit comprises a second tank (for the oil), a heater / heat exchanger (to lower its viscosity) a change-over valve, a purge valve & pump (to switch back to ordinary diesel quickly), filters, hoses & wiring.

Interested but unconvinced.

Chris

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Same but saving a few ££ would be wasted if the fuel harmed the longevity of the TDI

There seems to be more positive comment on the web about this than biodiesel in terms of engine longevity. I agree though that it is a concern.

Chris, you were talking about cooking your own diesel. What method ARE you convined about for running the engine?

Si

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:huh: I'd have to say I was interested as I am running my 2.5TD on RME biodiesel at the moment. The only real problem is that you have to get it in drums and hand pump it into the vehicle.

The government has a bit of a downer on straight vegetable oil, (SVO), at the moment, so I am not sure how you would pay the excise duty on the oil and at what rate. If you register as a fuel producer, (the usual way with RME or MWVF), then you agree to produce biodiesel that meets minimum standards that SVO won't meet.

www.bio-power.co.uk say that they are organising a conference in Wolverhampton in early December to discuss the issues, including the apparent harrassment by C&E, and maybe set up a new industry group.

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See here

The owner is a Land Rover enthusiast also.

I looked at plantdrive.com, but am not keen on the electric heating of the fuel. A heat exchanger has the advantage that even though it takes longer to heat up - and be able to run on SVO, it doesn't require a 100-150A alternator to run it!

Likely to be more reliable in the long run as well.

On the plus side, the kit that plantdrive.com is selling looks very nice - almost bling!

Si

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Be careful with veg oil. HM Customs are already clamping down on those applying to become biodiesel 'home producers' by closing the tax loophole and classing veg-oil as a ‘fuel substitute’. If its a fuel substitute, then you have to pay the same 47.1 pence per litre as the fuel that its replacing i.e. diesel, rather than the 27.1 ppl charged on 'home brewed' biodiesel. Add the regular pump rate of duty onto the price of a litre of Mazola and you stand to pay more for your veg-oil than you do a litre of real diesel! That is of course, assuming you were planning on logging all of your useage and repaying the duty to HM Customs in the first place...

I've also been lead to believe the LR injector pumps don't like veg oil, although someone will know doubt come along and tell us they've circumnavigated the world using nothing but neat chunks of yak's fat for fuel.

Personally there's too much conflicting information out there and too much to go wrong for me to be convinced. Besides, you know they will probably ban it eventually and then all you'll be left with is a redundant on-board deep fat fryer.

Kev

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Chris, you were talking about cooking your own diesel. What method ARE you convined about for running the engine?

The chemistry talked about here seems to make sense to me. All I know is what I have read and I understand that SVO has very long molecules (which makes it thick?) and not so fast/clean burning therefor it soots the injectors etc.. You can thin it with additives but that does not shorten the molecule length any. As I understand it you can make methanol react with the oil to break the long molecules down into three shorter ones. JamesM has a book on the subject which he copied part of for me - sadly it has become misplaced in our move... He may be able to shed more light on the subject.

I also understand that bio-diesel has a higher calorific value than mineral diesel - which explanes why I seem to be able to make it up the hill out of Dover/Newhaven so fast when returning from the continent. French diesel has to have 3-5% IIRC bio diesel by law.

Chris

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A mate of mine recently tried running a 50/50 mix of SVO and ordinary diesel, just as an experiment really.

It ran ok, but smelled like a chip shop, but the biggest thing that put him off was that he reckoned he'd lost the top 15 - 20% of power off the top end of the 200Tdi.

He's now back to running on straight pump diesel.

I thin theres a distinction to be made between SVO and biodiesel. Don't think you'd get these problems on Biodiesel.

But what do I know???? I run a v8!!!! B)

Jon

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A mate of mine recently tried running a 50/50 mix of SVO and ordinary diesel, just as an experiment really.

It ran ok, but smelled like a chip shop, but the biggest thing that put him off was that he reckoned he'd lost the top 15 - 20% of power off the top end of the 200Tdi.

He's now back to running on straight pump diesel.

I thin theres a distinction to be made between SVO and biodiesel. Don't think you'd get these problems on Biodiesel.

But what do I know???? I run a v8!!!! B)

Jon

SVO and WVO (Waste Veg Oil) have to be thinned by heat before they enter the injector pump. The viscosity reaches an acceptable level at about 82 degC, and you must also ensure that the pump is cleared of veg oil before shutting down - it will set in the pump otherwise.

CAV type rotary pumps are said to last the shortest when used with xVO, while the Bosch inline pumps do better. You need 2 tanks, a switchover solenoid valve and a way of heating the oil - ither electric or heat exchanger. That Neoteric kit is one of the first that was commercialised - the vegtherm heater is actually made up using diesel glowplugs IIRC.... You can make one fairly simply if you have the skills...

The comments about HMC&E getting a bit ar5ey are correct, as the govt have realised how big a market this is. You need to keep accurate records, and expect to receive a number of visits from odd inspectors at strange times.... Who don't need a warrant to seize your pride and joy...!! :ph34r:

There is a very good Yahoo! group to do with veg-oil, and there are a lot of advice about the technical side and the costs and tax issues.

I've considered coverting mine to WVO as I have a local chinese who could provide all the oil I could need. The only downside is that I will probably end up applying for a waste carriers licence just to cart away their old oil...!!!

Cheers

Pete

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it isnt the fact that pumps fail with veg oil but because some are better able to pump veg oil than others , due to the VISCOSITY of the oil , hence the bosch pumps are more capable of pumping the higher viscosity veg oil .

if you run a mix of diesel and veg oil then pretty much all injector pumps will pump this .

you can mix straight SVO with diesel but a 5% mix is best , although you can mix in whatever quantities you like up to 50/50 without problems in most weathers .

it will smell like a burger van running veg oil i can assure you .

you will read allsorts of recipies if you look on the net but how about 20litres heating oil with 1/2 litre 2 stroke oil mixed .

if using veg mix including veg then oil change fuel filter at 500-1000miles at first , then at normal service times after .

remember that diesel engines were actually designed to run on nut oil in the first place , it was fossil fuels that they werent designed to run on at first .

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remember that diesel engines were actually designed to run on nut oil in the first place , it was fossil fuels that they werent designed to run on at first .

I can assure you that my diesel engine was designed to run proper refined mineral diesel oil! The pump and injectors were all designed with this in mind, not peanut oil as Rudolf Diesel first demonstrated his compression ignition engine running. I fully accept that with the correct injection kit it will run on pretty much anything that will burn.

Chris

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JamesM has a book on the subject which he copied part of for me - sadly it has become misplaced in our move... He may be able to shed more light on the subject.

The book's called 'From the Fryer to the Fuel Tank', and here it is on Amazon.

The recipe is as described on the journeytoforever website (vegetable oil, Lye and Methanol). The book says that veg oil is made of three esters attached to a glycerine molecule (a triglyceride, visualised as an octopus with three legs), and that biodiesel is made using a transesterification reaction. During this reaction, the Lye acts as a catalyst and breaks the triglycerides up. The three esters get attached to the alcohol and turn into alkyl ester molecules (the biodiesel), and the glycerine reacts with the Lye and sinks to the bottom as soap.

There! Clear as mud. :P

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biodiesel is made using a transesterification reaction. During this reaction, the Lye acts as a catalyst and breaks the triglycerides up. The three esters get attached to the alcohol and turn into alkyl ester molecules (the biodiesel), and the glycerine reacts with the Lye and sinks to the bottom as soap.

Including, as I recall, a health/safety warning on managing the reaction, plus the need for relatively careful regulation of the temp. to make it work right, for those who make their own.

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I had a look through the site and I can't see any instructions concerning disposal of the 'soap'. I can't imagine you could just flush it down the drain can you?

A quick question - Is industrial methylated spirits the same as this Methanol stuff? It's just that I happen to have 15-gallons of it!

Les. :)

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Did I read that the military were running their Landies on aviation fuel in Iraq?

It is reportedly free, gratis, from the good old US of A.

Aviation fuel is basically parraffin, (kerosene if you speak American) my Disco runs fine on Esso Blue with 2 ltrs of cheap oil per tank full. Problem is I have to make sure its all gone before I leave the private pay and play site and go back on road.

The problem with veg oil is that when it gets cold it gets thick, when it gets thick the pump cant handle it and breaks. The problem of "set" veg oil in the pump and filter is covered elswhere.

Now if anyone has tried veg oil mixed with aviation fuel (tax free by the way) plus a slug of methanol let me know how it goes, preferably after completing say, 50k without trouble.

Closing thought, a Jumbo jet burns 4 ton of fuel on a trip over to the USA, its all tax free, and costs about 38pence a litre. Not fair is it? (You can get commercial white spirit at about 40 p a litre in 50 gallon drums, (I know they are in ltrs but I never converted fully).

Geoff

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I had a look through the site and I can't see any instructions concerning disposal of the 'soap'. I can't imagine you could just flush it down the drain can you?
Actually, I think you only get soap if you've added a bit too much Lye otherwise it's just glycerine. iirc, the book says that you can chuck the glycerine on the garden - it's fairly harmless stuff. You could probably dispose of any soap down the drain once you'd recovered any surplus methanol from it. This page suggests what to do with the by-products.
A quick question - Is industrial methylated spirits the same as this Methanol stuff? It's just that I happen to have 15-gallons of it!
Unfortunately not . Methanol is apparently quite difficult to get hold of - I believe Chris W tried to find a supplier and didn't have much luck.
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I had a look through the site and I can't see any instructions concerning disposal of the 'soap'. I can't imagine you could just flush it down the drain can you?

A quick question - Is industrial methylated spirits the same as this Methanol stuff? It's just that I happen to have 15-gallons of it!

Les. :)

I think you can use it as fertiliser?

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