Oil

[Benhim]

After reading Dennis Parks book I have some concerns about firing ware with used motor oil, or even no. 2 diesel. These contain small amounts of metals like manganese and lead. Does anyone have experience in using used motor oil as fuel? If you have experience in firing with oil I'd like to hear your thoughts on the idea of using motor oil as fuel for functional ware, as well as any experience you can impart with regards to the use of motor oil as a fuel.

[Marcia Selsor]

Dennis Parks is a friend of mine. We both have designs in the Studio Potter book for oil. Mine is for a household oil burner that uses #2 diesel oil. Motor oil is heavier and harder to combust. It needs a hotter atmosphere to ignite. If you took the kiln up to red heat, then switched to motor oil, you would be fine. The motor oil has a lot of BTUs. I had a friend, Bill Weaver, in Bowling Green KY

who used charcoal briquets in a coffee can to filter motor oil. There can be metal crud in old oil. As for whatever minerals are found in the oil, I can not say. That would have to be tested.

Marcia

[Guest JBaymore]

Like a lot of things that seem to "make sense" when looked at from one viewpoint, the question of using old car crankcase oil for kiln firing looks like an environmentaly good thing at first glance. But there are parts of that whole idea that need to be scruitinized far more closely.

 

Quickly, it looks like a "good thing"...... using a plentiful waste product to do something positive.

 

Is burning X gallons of this used motor oil product having less overall total environmental impact than burning X cubic feet of natural gas, or X cubic feet of wood, or X gallons of liquid propane, or X kilowatt hours of electricity? To study that acurately would take a research grant. You'd have to look at the "birth to death" impacts of obtaining those other fuels and compare it to the same "birth to death" impact of the motor oil. It is far more complex than the typical "potter-level science" kind of study of such things will show.

 

You might have read through this information to get a better idea of what actually is IN waste motor oil and some of the potential concerne with it:

 

http://www.nature.np...xic/oilused.pdf

 

 

 

One small excerpt:

 

"Used motor oil is generally similar to new motor oil except

 

 

for the addition of additional:

 

 

 

Metals including zinc, magnesium, barium, lead, aluminum,

 

 

 

chromium, copper, iron, manganese, nickel, silicon, and

 

 

 

tin [752,961].

 

 

 

Water, gasoline, antifreeze, and thermal or breakdown

 

 

products of various hydrocarbons [961]."

 

And

 

 

"METAL CONTENT

 

 

Other Metals (ppm):

 

 

 

Aluminum 15

 

 

 

Copper 18

 

 

 

Iron 220

 

 

 

Lead 18500

 

 

 

Silicon 17

 

 

 

Antimony 6

 

 

 

Sodium 59

 

 

 

Calcium 688

 

 

 

Barium 177

 

 

 

Zinc 1360

 

 

Magnesium 410"

 

 

And

 

 

"In contrast to metals, most organic compounds (99.4 to 99.9%)

in WCOs are destroyed during combustion in commercial boiler

 

 

 

systems. Under certain circumstances, however, detectable levels

 

 

 

of polychlorinated dibenzofuran and polychlorinated dibenzodioxin

 

 

 

compounds can be formed during the combustion of WCOs.

 

 

 

Photodegradation half-lives for several PAHs that could potentially

 

 

 

be emitted from stacks, including fluorene, naphthalene,

 

 

 

acenaphthene, anthracene, benzo(a)pyrene, phenanthrene, and pyrene,

 

 

 

range from 0.37 hours to 550 days based on single substance

 

 

 

experiments conducted under laboratory conditions. Mixtures of

 

 

 

PAHs and particulate-bound PAHs are more resistant to

 

 

 

photodegradation, particularly in the presence of other organic

 

 

 

compounds. Limited data are available concerning the fate of nonmetallic

 

 

 

inorganic substances such as sulphur, nitrogen,

 

 

 

phosphorus, and halogens that are emitted to the atmosphere

 

 

following combustion of WCOs [752]."

 

 

 

 

best,

 

......................john

[Benhim]

I've read extensively on the possible side effects of combustion of waste motor oil, but I've seen little testing done on the contaminants contained in the ware from a motor oil kiln. My guess is that the metals could potentially build up in the ware to the point that they could become unsafe. This could potentially have a delayed effect as metals build up in the kiln itself.

 

As far as the environmental impact is concerned aside from the immediate concern of phosgene gas, PAH's are probably the biggest long term concern.

[AndyL]

Frankly this post is intriguing since at some point I'd like to build my own kiln. I wish I could offer some insight but lack of experience prevents it. Good luck with your investigations into this subject. I hope whatever design you use or develope from gives you great results. When you do I'd like to read about them in these forums.

[Guest JBaymore]

................ but I've seen little testing done on the contaminants contained in the ware from a motor oil kiln. My guess is that the metals could potentially build up in the ware to the point that they could become unsafe. This could potentially have a delayed effect as metals build up in the kiln itself.

 

You are correct on the "seen little testing" comment, for sure. Unfortunately there is little real technical research on such subjects to draw upon. Heck........ there is little decent research on the leaching of anything out of any types of studio ceramics glazes........ let alone on a niche subject like this.

 

In my college ceramic chemistry classes I talk about the tendency of art/craft potters to take the "if it looks like a glaze, walks like a glaze, and quacks like a glaze, it is a glaze" approach that is almost always taken. Various raw materials are combined and fired, and then the macro-visual Mark 1 eyeball inspection is usually about the only formal "testing" that is done before that so-called glaze is put into use. From a technical standpoint (stability, hardness, suitability to purpose) it might be OK or not OK.... but really.... that is not investigated much or at all.

 

There certainly is room for far more formal investigation on this whole subject, and certainly on the waste oil impacts subject.

 

However, those of us who are "tech weenies" in the handcraft end of the field are, like most artists, working hard to make a living. So time and money to dedicate to such research is hard to come by. Between teaching at the college and making pots, I know that I simply don't have to time to devote to the structured controlled research this would take to be accurate. Nor the funds for the extensive lab testing work. Wish I did.

 

I too would also suggest that the metals could possibly deposit into the molten glazes and over time, tend to impregnate the internal refractories. That is a known property already with lead fumes in kilns that have been used extensively firing lead-based glazes. So it likely follows. And since lead compounds are one of the largest ppm-s in the metals category listed for recalimed motor oils, that is likely a factor.

 

Along with the various combustion by-products, I'd also be a bit concerned about long-term lead fume escaping the kiln ventilation systems into the working environment.

 

best,

 

..............john

[Benhim]

I have a real affinity for Pennsylvania Redware. As you might know this traditional style of pottery contains lead. Because this ware today has a primary use as an art object it's one process that wouldn't be harmed by the use of motor oil as fuel. It would seem the minor addition of lead or other contaminants in any art object would not be harmful to the user. I guess I'll just have to do the testing myself.