BioDieselNow - Renewable biodiesel fuel

So how about it? Unfortunately, I have natural gas heat and haven't paid close attention to bioheat developments. What percentage is safe to blend in an unmodified old heater? How about a virgin one?

What modifications need to be made to properly run a boiler on biodiesel at various percentages? Any?

Pardon my ignorance on this. Ideally, we can come up with some really good answers and we can do an article/blog about it. I'm confident that the BDN users can provide a solid answer.

 

Anyone? Bueller?

I'm on my town's alternative energy committee and we're going to do a presentation tonight to the board of selectment about buying some b5-b20 to heat town hall. I'd like to go in there with a full knowledge of what I'm talking about.

Nate ,

I am in Texas , and we tend to worry more about air conditioning than heating down here . There is however a section over at infopop on heating with biodiesel . I have looked at it a few times , but am far from an authority on the subject . There are members over there who are using biodiesel instead of heating oil , but I am not sure what mods if any were needed to thier furnaces . You might want to take a look over there and see if you can find the answers you need . Good Luck

I picked up what I could off NBB and ran with it. An anonymous group from town actually volunteered to pay the difference in cost! Unfortunately, we already ordered our 500 gallons and probably will be set for the winter.

I have been burning an increasingly larger percentage of Biodiesel for three months in a home heating boiler( circa 1987 Crown Freeport) this is a three passage design w/ round horizontal chamber firebox , forced hot water boiler with a Beckett AFG burner and a Suntec oil pump. No system modifications were done. Here is my report: As the percentage of biodiesel to petro went up (as I added more B100 to the tank) I needed to adjust several features on the burner to sustain combustion: The oil pump pressure Up, the air flow UP, and the nozzel position further into the firechamber. HOWEVER I recomment that all of these adjustments be done by a burner tech with instruments, due to the fire hazards involved. ALSO, mal adjusted burners may result in a soot plugged boiler! After three months I noticed that the boiler comes up to temperature about the same time as with #2 oil but it burns with a bit more smoke, the flame went out a number of times but with continued adjustments I have solved this. It takes a bit of fiddling and the adjustments must be balanced against each other so as to maintain proper draft, flame retention, combustion efficiency, and CO output. The fuel filter needed replacing several times. Currently I am burning unwashed B100 to save on waste water ,so far so good, the house is nice and toasty and the pump has not begun leaking yet. Future changes: B100 oil pump, smaller output nozzel with a solid spray cone, This is all experimental & I will keep yall posted.

Are there any burner techs here who can explain why biodiesel needs to be atomized at higher pressure, more air and the nozzle head extended farther into the air tube than with #2 oil? i suspect it has mostly to do with viscosity, maybe it's the chemistry of bio combustion, but I am concerned that the nozzle will overheat with these settings. Currently I have installed a smaller nozzle and maxed out the pump pressure which allows a sustained, stable, clean burn with unwashed bio, no more problems so far....

Purely conversational info, but I recently quizzed my furnace repairman when I needed a new control box installed on my ancient oil furnace... Here in Seattle there are quite a few home heating oil suppliers that offer B20 splash-mixed for about $0.15 more per gallon. This fella assured me that I needed no conversion at all to switch to B20, I just needed to fill up the tank and go. I'm going to try it on my next tank and see what happens.

Cheers!

I agree, B 20 should be no problem, but any more than that and adjustments need to be made. I think I figured out why the air tube needed to be reconfigured in my boiler; Biodiesel has a higher flash point, so finer atomization is needed to achieve a clean burn. The smaller nozzle with a hollow spray cone shape and higher pump pressure achieve this. You can try this experiment when you use a spray bottle: notice that when you don't squeeze the trigger as hard you get a coarse spray rather than a fine mist. Bio is also thicker than petro. A burner that is set up for #2 oil has an air flow stream directed tightly around the nozzle, and since bio needs more heat to sustain a flame the air flow needs to be spread out so that the flame is essentially not blown out by a narrow high velocity air flow. Adjusting the nozzle head position in the air tube can spread the air around the flame so it does not blow out. However this works on my particular boiler and required extensive tweaking, your results may vary.

Fyberfuel:

Are there any burner techs here who can explain why biodiesel needs to be atomized at higher pressure, more air and the nozzle head extended farther into the air tube than with #2 oil? i suspect it has mostly to do with viscosity, maybe it's the chemistry of bio combustion, but I am concerned that the nozzle will overheat with these settings. Currently I have installed a smaller nozzle and maxed out the pump pressure which allows a sustained, stable, clean burn with unwashed bio, no more problems so far....

 

Im an hvac tech in Md. Lets see if I can shed some light on this subject. I am very in using b100 as home heating fuel.  I have not yet tried it personally ...yet.

Ok Bio has a higher ignition point than #2 so that is why it needs to be "atomized at a higher pressure".  Now adding more air and inserting the nozzle gun assembly further into the fire box have me a little confused.  Bio burns cleaner than #2 so that should mean you could turn the air down some.  The nozzle gun further in the fire box could be improving the mixing of air and fuel.  Now I think I read somewhere that you get slightly less btuh's from a gallon of bio than from a gallon of #2.  This should mean that you need to increase the nozzle size to get the same amount of heat.  Since bio needs a higher spark/flame to ignite/burn it possibly even a step bigger nozzle should be used so plenty of fuel is available to keep the temp up in situations where the flame is going out.  The larger nozzle should help with the maxed out pump pressure.  Now im still speculating about the type of nozzle.  A or B  there are also slightly different variations.  These are hollow or solid cone.  Now you should always stay with the angle  of cone that the data plate recommends.  It seems to me that the hollow cone could be more helpful with what you are describing.  It would let the air enter the center of the cone to promote better/more complete combustion. 

 Now to run b100 youre going to want to change to an oil pump that has a viton seal.  They are commonly available on ebay.  Other than that the furnace needs to be properly tuned which any COMPETENT tech should be able to do.  Let me know if you have any more questions.
 

Thanks for your tips, it's been a few months now burning unwashed B 100 and I can say that there is no sooting, a nice clean burn of white deposits in the fire chamber, 350 to 400 degree stack temp and the unit fires perfectly every time. I dont even think about it anymore. I set it up finally with almost the same air flow and nozzle as recommended by the manufactrer except that it is slightly smaller by .05 gph and the pump pressure is higher. Next year I will try to see if a larger nozzle works. At this point I am totally convinced that unwashed B 100 can be used to heat a home with a conventional boiler set up with the proper adjustments. and Yes I recommend a certified tech do the job. I will open the boiler at the end of the season and give a report on that.

Hey there, I'm currently 1. having some troubles with my furnace and 2. wanting to switch to BD. Anyway I can get ahold of you? Figger to kill 2 birds with 1 rock so to speak.

BTW I'm down in Burtonsville 

Probably best to get a burner tech over there, it will cost around $100 but at least the job will get done right with the right equipment. What I am doing is experimental (burning my own unwashed fuel) and not generally the best way to go for most people who have oil burners. So far this method works for me but I have had to make modifications to my burner air tube to get it to work properly.

I have been using b100 in my furnace for almost 2 years .Every now and then the furnace doesn't fire and it occassionally needs to be cleaned up.Intring to find a cure for those problems I recently got some info from a person who should ''know'' which you might find intersesting.--The guy says do 3 things -use a preheater-use a size smaller nossle--and lower the pessure-- . I bought a preheater for $32 and its taken care of 75% of my problems. I havn't tried to lower the pressure yet but the reasoning behind it is to get the flame closer to the ignition.I'm told you have to get the flame to yellow-white color to make things work properly.--Maybe someone out there has tried these things and can fill us in.Hope this helps someone out there and and would like to hear if you have any other information on this subject. thanks

A pre heater aye, That sounds good, where do I get one. As far as the fuel pressure- I'm with the school that says to increase the fuel pressure so that smaller spray droplets are formed which lowers the ignition temp. I have proven this on my boiler because when I lower the pressure(to normal for petro)- the flame goes out. However, depending on whether or not a burner has a flame retention relay (which shuts the igniters off after a flame has been established)- or a constant ignition setup, the lower pressure theory may hold.

You can purchase a pre-heater from Patriot_Supply.com   phone 866-321-4822  . The one I bought is a beckett nozzle line heater. #rwb51621.. price was $32.50. It has helped alot!!!!!     On lowering the pressure ,I did so alittle over two weeks ago. Its run perfect so far .In fact the furnace never sounded as good as it does now .Maybe it's the real deal .

Thanks man, I'll check out the pre heater, that sounds like the ticket. As far as oil burners are concerned, I think that each setup is different because of the many variables involved in current generation oil heating equipment. Each unit has to be set up individually to its own specs so- what might work for one does not work for all. At this point I do not think that petro oil burners can be used to burn bio right out of the box; they all need some mods and adjustmernts to optimize performance. Hopefully more burner techs will educate themselves to the features of biodiesel and wil be better able to help set up a burner for efficient safe and most improtantly reliable operation with this fuel. I predict that the industry will be able to manufacture a burner which can self adjust to burn many types of liquid fuels- be it SVO,WVO, Bio, Petro, or waste motor oil.

I have been using b100 all winter trying all kinds of things .Some good most not but I have an unlimited free parts supply .
First of course unwashed B100 will burn better so will your gas car with Methanol in it but for how long .
Unwashed B100 will give you better power and mileage . Thats the Methanol but for how long ? It will eat your injector pump and everything on your fuel system .
I read and tried JTF's using 1/2 the Methanol . Dose not work cant even pump it . Maybe with a fuel heater .
I tried a larger tip . Boy did I get fire turned it off and through a match in the firebox . It burned for a good 30 min. Tried a smaller one no fire at all . So I am staying with the original tip . I still do not have it down 100% and like someone here said there are so many brands that not one way is rite for them all .

I would recommend get it tuned up by a pro . Then you have a good starting point . Keep a good log of every change you make and only change one thing at a time . That way if something is not working it's easy to go back .

Good luck