I don't understand why people would let knuckleheads talk them into using plastic.  Maybe I'm stating the obvious that plastic is made out of oil and if it were to some how catch on fire it would burn for a substantial amount of time( not to mention the fact that the fumes produced by the fire aren't too good to inhale) along with the contents inside(Vegetable oil, high in BTUs along with methanol which is just a tad bit flammable as well) if left unattended or unnoticed.  Call me crazy but I don't understand why anyone would buy any of the processor kits with plastic tanks, not to mention that they are outrageously priced.  

^^^  I think shipping is the determining issue.  Steel processors are harder to handle and more costly to ship.

I would suggest that after reading the other replys.. building a reactor out of a plastic reactor might fall victim of weakness in an appleseed design.. some of those being 1. non explosion proof pump. might be an issue with methanol vapors 2. poor control of methanol vapors..later designs address this issue. Its hard to apply some of these to a plastic tank 3. how/where to heat..I have been heating in plastic tanks for more than 2 yrs. the only problems happen when the element touched the side and melted a hole.. I think of the other setup tried to mount the heating to the side of the tank..this is bad and could easily lead to a fire!..after the contents emptied the heating element will over heat fast. 4. poor control of the heating element under a pump failure. later designs also address this issue. does these make a plastic reactor bad.. consider what might happen if you must use acid esterification in the steel tank with steel pipe? plastic is far more chemical resistance. just food for thought.. -dkenny

I have been using a plastic tank for 2 years with no problems, I heat the oil to 125-145 degrees and have not noticed any softening of the plastic, you need to re-tighten fittings from time to time, as the plastic and steel fittings expand at a different rate. This has not been a big deal. The plastic is easy to clean out with a garden hose, and is very durable, I am a firefighter and would not use it if I thought it would cause a fire, I always keep a close eye on it while it is running, do not go in the house and forget about it, plan it so you are close by and can look in on it every 20-30 minutes until you unplug it.

c.

buckmike:

I have been using a plastic tank for 2 years with no problems

This is what is called anecdotal evidence. When I was young, we employed a crop duster that used duct tape to repair the wings of his biplane. Sure, he made it work without problem (for a while), but this isn't a safe method? Would you want it adapted by everyone because it worked in this situation? Keep in mind, there is plenty of evidence indicating plastic tanks are unsafe. There have been fires fueled by plastic tanks systems that would've been a non-issue with a steel tanks.

buckmike:

I am a firefighter and would not use it if I thought it would cause a fire

I've spoken with a handful of fire inspectors, none of which would approve the use of plastic tanks for this process.  A certified (PE) environmental engineer (and fellow instructor), specializing in gas stations, refineries (ethanol), and other fuel-related facilities scoffs at the thought of using plastic tanks; the Department of Commerce here says the same. Perhaps they are better informed of the dangers here (the state has put forth effort on the biofuels topic), but other experts agree (Penn State Biodiesel Best Practices Guide).

The only people I know that defend plastic tanks systems either:

1. profit from selling them
2. are cheap and have placed safety as a low priority
3. been suckered into buying one (typically for large amounts of $$$$) and defend it to justify their purchase

I've made well over 150,000 liters of biodiesel with plastic tanks . I heat to 180+ F when I am drying and my tanks are rated to 140 F with no problems of melting or fires , a little care and common sence and theres no problem . Someone had a fire in a plastic tank years ago and the picture keeps showing up all over the biodiesel sites but not how or why .

Most all the people who don't like plastic are appleseed producers . Appleseed is fine for a TDI but when you go through as much fuel as I do I would be making biodiesel 24/7 just to keep up . Try to make 90 gallons a day with an appleseed .

Terry

terryrret:

Someone had a fire in a plastic tank years ago and the picture keeps showing up all over the biodiesel sites but not how or why .

This is false. The two most common accident types I've seen reported are caused by a) welding on vapor filled tanks, and b) accidental fires that ignite surrounding materials, including plastic tanks. Here is a more-recent example that led to the garage doors of this residence being blown off (literally). Note, there was publicly-available video showing a compromised plastic inductor tank in this garage; this link has since expired.

terryrret:

Most all the people who don't like plastic are appleseed producers.

Did you do a poll? Most individuals I know who regard this practice as unsafe are either industry professionals, educators in the field, professional engineers in the field, are fire-safety inspectors, or are involved in regulation.

The rationalization you make, justifying the use of unsafe equipment on the grounds of increased capacity, is just odd. Metal tanks can be had inexpensively, and you need to implement greater safety measures as your volume increases, not fewer.

No where in the did it say they were plastic tanks .I could interpit the metal tank in the garage had to much presure causing it to blow up . Typical mis information . The message is alway make biodiesel in a well ventalated area .

Terry

terryrret:

No where in the did it say they were plastic tanks .I could interpit the metal tank in the garage had to much presure causing it to blow up . Typical mis information

I was specific in stating that there was a video link showing the damage, and more specifically the melted plastic inductor, and that this link was removed from the FOX affiliate in question (I posted a screen shot from this video we used in our biodiesel class at the college).

Accusing me of spreading misinformation is baseless; I have no need to make up such stories as they seem to happen too often. This particular fire was started by oily rags that spontaneously ignited, and the fire spread to the nearby flammables (including the processor, which wasn't being used at the time ... fortunately). Including research into biodiesel-environmental issues, I have at least 100 hours of research into biodiesel safety issues over the last two years. Whether you like my findings or not, I have provided a fair assessment of the situation.

 

After a bit of digging, I found the FOX station moved the link here. At about 50 seconds in, the melted processor is shown quite clearly:

Notably, the report's description of the fire's progression follows other after-the-fact reports, though the ignition source I mentioned above is the correct one.

So where dose it say the tank started the fire ?

Terry

The plastic seal used in the H.F. and N.T. pumps is not made to handle methanol or biodiesel.

These seals will leak soon after being used to make biodiesel.

I have seen a H.F. pump blow a seal and start spraying biodiesel.

The use of these pumps AND a metal tank is bad enough but using these pumps with a plastic tank is really asking for trouble.

 

If people can not figure out how to make a biodiesel setup without using plastic tanks or cheap pumps with the wrong type of seals and no current overload protection then I suggest they build a Canoe Paddle Processor. 

Or maybe Two !  

I haven't had any problems with my plastic tanks. I also work offshore on a production platform so I know about methanol approved seals and stuff like that though. I guess I would suggest everyone really get educated on this process before jumping in. Alot of it is just common sense though, ie.. Look at the turkey fryer. Maybe some people should just keep it simple and leave this kind of stuff alone.

This thread is dedicated to discussing the application of plastic (HDPE, MDPE, LDPE) inductor (cone) tanks as biodiesel reaction vessels. Click for the informative summary "sticky" post for this discussion is linked here.

 

 

I also think that one of the big problems is that  most of the "cheapo make your own biodiesel processors" DO NOT USE FLOURINATED plastic.

Without this process the plastic is pourus and subject too internal stresses that will lead to microscopic crazing , cracking and then failure. If you have been making bio and you used the cheap homedepot clear water hose to siphon out the bio. You will see quite quickly that the hose is always wet with bio but never shows signs of a crack. This is because the bio is leaching thru the pourous plastic molecules chains. the same will happen to any plastic if during construction the cellular structure is not sealed.

Hope this helps ,

joeD