# Incineration



## bswartzwelder (May 24, 2012)

I have several small containers with escrap which I am considering incinerating. One container has cell phone parts which are either too difficult to use a chemicasl process on because they are flexible connector strips or are too small to deal with any other way. The other container has cell phone circuit boards where almost all the components have been removed. I have a kiln which I would like to use for the incineration process. What temperature should I set the thermostat to, and how long should I leave everything in when cooking them? Anyone else use a kiln for this? All input is welcomed. I know the circuit boards have a good bit of gold, but they also have some solder on them.


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## Oz (May 24, 2012)

The gases from incinerating circuit boards are very toxic. Unless you want to install after burners and fume control, it is a non starter in my opinion. No amount of gold is worth your health or life.


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## 4metals (May 24, 2012)

Incineration requires oxygen for complete combustion, a closed electric kiln will give you the heat but not the required air for complete combustion. And like Oz said, without an afterburner to burn off the uncombusted gasses it will be toxic in a wide circle around where you do this.


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## NobleMetalWorks (May 24, 2012)

I am in the process of making an incinerator out of a beer keg. This is what I am basing my design on.

I am not sure why, but when I try to use the youtube code, it's not working for this video, so I just inserted the link instead.

http://www.youtube.com/watch?feature=endscreen&NR=1&v=cdHKBwLAWOM

These are also called cyclone incinerators. The fire is kept at the bottom, and air is forced into the top. I am going to use a leaf blower for the air flow. The idea is to keep all the particulates under the air shroud created by the induced air flow. That way you loose very little values in the incinerating process.

Here is a home made one, again in a 55 gallon steel drum. It's cheesy, but you can get an idea of how a custom made incinerator can be built, and improved upon.

[youtube]http://www.youtube.com/watch?v=exJ9Y0KgVWk&feature=related[/youtube]

If I were to build one totally from scratch, with stainless steel/steel plates, I would investigate this design more, it puts the exhaust into the burn chamber a second time so that the pollution output is less. The design should also prevent any values from escaping the burn chamber.

They claim it's totally smokeless

[youtube]http://www.youtube.com/watch?v=1GtIWd-OVlM[/youtube]

Here is their website

http://www.emakmakina.com/30-waste-burning-oven.html

Here is a video of someone making a large incinerator for a farming operation. Larger scale.

[youtube]http://www.youtube.com/watch?v=MTs2ceCk8q0&feature=related[/youtube]

I am using the cyclone design, and because I do not need a huge one, I am using a stainless steel beer keg.

Scott


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## 4metals (Jun 2, 2012)

I have incinerated many pounds of circuit boards in my day and I have also burnt in the drums you have just described. But I would never burn circuit boards in the drums. Elastec makes them and they excel for brushes and wheels and flammable materials but without an afterburner I would not burn PCB's in them. http://www.elastec.com/portableincinerators/mediburn/videos/ Too much unburnt fume. 

One reason I've lived as long as I have while actively refining is I strongly believe in controlling noxious fumes, they will age you fast! Be smart, use an afterburner at least 1800 F with a 1 second retention time.


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## goldenchild (Jun 2, 2012)

4metals said:


> One reason I've lived as long as I have while actively refining is I strongly believe in controlling noxious fumes, they will age you fast!



No kidding! I watched the third video SBrown posted and then started watching some of the suggested videos that pop up after the video is done. Eventually I came upon this one. I think it’s extremely appropriate not only for this thread but for the entire forum. It shows just how fast things can go wrong and why safety and proper precautions are paramount in what we do. I do put out this warning though. The video is a bit disturbing and not for the faint of heart. If this applies to you please use discretion and * DONT* watch this video.

[youtube]http://www.youtube.com/watch?v=lzObhHet9QM[/youtube]


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## jeneje (Jun 3, 2012)

Have a question?, I am building a wood burning incinrator for PCB's out of 2 55gallons drums. One is lined with 3000% firebrick the other i planed on using as a thump barrel with water in it. Will pushing the smoke into the water barrel scrub the smoke clean before exiting as steam.
Ken


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## Geo (Jun 3, 2012)

you will still wind up with a toxic mess and i dont think it would scrub all the smoke. an after burner is really the only way to remove the largest percentage of the toxic smoke.


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## NobleMetalWorks (Jun 3, 2012)

4metals said:


> I have incinerated many pounds of circuit boards in my day and I have also burnt in the drums you have just described. But I would never burn circuit boards in the drums. Elastec makes them and they excel for brushes and wheels and flammable materials but without an afterburner I would not burn PCB's in them. http://www.elastec.com/portableincinerators/mediburn/videos/ Too much unburnt fume.
> 
> One reason I've lived as long as I have while actively refining is I strongly believe in controlling noxious fumes, they will age you fast! Be smart, use an afterburner at least 1800 F with a 1 second retention time.



Good point, I have never burnt PC Boards myself, but I am planning on scrubbing the fumes. I picked up two fume filtration units used in construction that use carbon and other filters to clean air at a garage sale. I think the problem is going to be cooling down the heated air enough so that the air can migrate through the filter system without melting any of the components.

By a afterburner, do you mean a return of the fumes back into the incinerator, to be burned again, similar to what is done with the exhaust from some cars? Or are do you mean a secondary burner that processes the exhaust from the incinerator?

Scott


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## jeneje (Jun 3, 2012)

Geo said:


> you will still wind up with a toxic mess and i dont think it would scrub all the smoke. an after burner is really the only way to remove the largest percentage of the toxic smoke.


Geo what type of toxic fumes are we talking about? Just thinking, can they be run through a filter system after being scrubed in the water first.


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## Geo (Jun 3, 2012)

from wiki : Phosphorus and antimony oxides and their reaction products can be formed from some fire retardant additives, increasing smoke toxicity and corrosivity. Pyrolysis of polychlorinated biphenyls (PCB), e.g. from burning older transformer oil, and to lower degree also of other chlorine-containing materials, can produce 2,3,7,8-tetrachlorodibenzodioxin, a potent carcinogen, and other polychlorinated dibenzodioxins.

the resins in printed circuit boards is loaded with this stuff.if you incinerate boards and it leaves any black soot or carbonaceous material, it will be toxic and very unhealthy to come into contact with.

an after burner is used on any commercial incinerator. normally it consist of of natural gas burners near the top of the smoke stack. 

in the old days, 10 microns was considered a safe filter size but if you want to be safe, you should employ several different size filters reducing in size. HEPA filters are expensive but should be the last filter before exhausting.


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## jeneje (Jun 3, 2012)

Geo said:


> from wiki : Phosphorus and antimony oxides and their reaction products can be formed from some fire retardant additives, increasing smoke toxicity and corrosivity. Pyrolysis of polychlorinated biphenyls (PCB), e.g. from burning older transformer oil, and to lower degree also of other chlorine-containing materials, can produce 2,3,7,8-tetrachlorodibenzodioxin, a potent carcinogen, and other polychlorinated dibenzodioxins.
> 
> the resins in printed circuit boards is loaded with this stuff.if you incinerate boards and it leaves any black soot or carbonaceous material, it will be toxic and very unhealthy to come into contact with.
> 
> ...


Thanks Geo, sounds like a nasty bunch of stuff. Will propane get hot enough to re-burn or only natural gas. Also, how could i test the smoke for toxic's?


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## Geo (Jun 3, 2012)

propane will work. the reason natural gas is used is because it is more cost effective. propane cost more. without some sophisticated technology, theres really no way to measure toxins so you have to assume that any black smoke or soot or carbon left from incomplete combustion is toxic. as long as your incinerator is white and chalky when you finish with no black ash, you will have successfully incinerated the mass properly. its a good idea to handle ash with care, use a respirator rated for smoke particles and gloves and eye protection until the material has been rinsed well. you really cant be too safe.


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## jeneje (Jun 3, 2012)

Geo said:


> propane will work. the reason natural gas is used is because it is more cost effective. propane cost more. without some sophisticated technology, theres really no way to measure toxins so you have to assume that any black smoke or soot or carbon left from incomplete combustion is toxic. as long as your incinerator is white and chalky when you finish with no black ash, you will have successfully incinerated the mass properly. its a good idea to handle ash with care, use a respirator rated for smoke particles and gloves and eye protection until the material has been rinsed well. you really cant be too safe.


Thanks Geo, What temp does it take for complete incinration and will wood acheive this. It seems i might be going in the wrong direction here.
Ken


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## butcher (Jun 3, 2012)

With the help of Google.
PCBs (poly chlorinated biphenyl) were in older fluorescent lighting fixtures, electrical appliances containing PCB capacitors, old microscope oil, and hydraulic fluids.
These are also in older transformers in oil filled type (usually larger high voltage can or tank type, these in a fire are extremely deadly, they have been phased out but older equipment you still rum into them. 
These PCBs (poly chlorinated biphenyl) are not the same as PCBs (printed circuit boards), although you could form these HCl poly chlorinated biphenyl compounds from burning circuit boards and electronic waste, as well as a whole lot of other toxic compounds.

Printed circuit boards (PCBs) are epoxy resins in fiberglass in epoxy resins, Teflon, phenolic cotton papers, many different types of metals
FR-4 is by far the most common material used today. The board with copper on it is called "copper-clad laminate".
Copper foil thickness can be specified in ounces per square foot or micrometers. One ounce per square foot is 1.344 mils or 34 micrometers.
Usually coated in benzimidazolethiol, prevent surface oxidation of bare copper.

Solder was a tin and lead, newer solder compounds used today comply with the ROHS restricts but does not eliminate the use of lead. One type of lead-free compounds is 99.3% tin, 0.7% copper, 0.05% nickel, traces of germanium.

Silver can be used but manufacturer’s will scrimp every penny they can when making millions of circuit boards or components, and still trying to compete and make a profit these penny’s add up to a lot of money.

Plating’s used organic surface protect-ant, immersion silver, immersion tin, electro less nickel, with immersion gold coating, and direct gold plate on nickel over copper or kovar. Tin forms and other metals form metallic’s such as Cu5Sn6 and Ag3Cu that dissolve into the Tin as well as lead can dissolve gold at soldering temperature. 
Electronic scrap components contain contaminants such as lead, cadmium, beryllium, brominated flame retardants, Some computer components can be reused in assembling new computer products, while others are reduced to metals that can be reused in applications as varied as construction, flatware, and jewelry. Epoxy resins, fiberglass, PCBs, PVC (polyvinyl chlorides), thermosetting plastics, lead, tin, copper, silicon, beryllium, carbon, iron and aluminum.
You can also have amounts of cadmium, mercury, and thallium.
Trace amounts include americium, antimony, arsenic, barium, bismuth, boron, cobalt, europium, gallium, germanium, gold, indium, lithium, manganese, nickel, niobium, palladium, platinum, rhodium, ruthenium, selenium, silver, tantalum, terbium, thorium, titanium, vanadium, and yttrium.
Almost all electronics contain lead and tin (as solder) and copper.

Americium the radioactive source in smoke alarms, carcinogen.
Mercury, switch’s fluorescent tubes flat screen monitors, sensory impairment, dermatitis, memory loss, muscle weakness, mental problems, nerve problems.
Sulfur and compounds in batteries, liver damage, kidney damage, heart damage, eye and throat troubles, and in lungs gases can create sulfuric acids.
Chloride gases can also form acid in the lungs.
Flame retardants found in plastics of most electronics. Health effects include impaired development of the nervous system, thyroid problems, and liver problems.
Cadmium, Found in light-sensitive resistors, corrosion-resistant alloys for marine and aviation environments, and nickel cadmium battery. The inhalation of cadmium can cause severe damage to the lungs and is also known to cause kidney damage.
Lead solder, toxic lead fumes---- toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous system. lead is especially toxic to children. Symptoms include abdominal pain, confusion, headache, anemia, irritability, and in severe cases seizures, coma, and death.
Beryllium oxides in heat sink greases, carcinogen and may cause chronic beryllium disease.

After burners are like a furnace in your flue, they re-burn the gases that did not burn in your furnace the first time, the fumes even after the after burner would need to be run through a scrubber and filters, not something most people could build at home in their back yard. And even if they did, have you discussed your plans with your local EPA officer and the department of environmental quality, the may require you to have permits and inspections if they did not just put you in hand cuffs just for thinking about doing what your planning to. 
I suggest you think twice, and look carefully what is below this bridge, you are thinking about jumping off of, you could find it a hard landing if you did not kill yourself or others first.
My advice leave burning of electronic waste to the large refinery, sell your scrap to them and buy refined gold and retire a healthy man, not some unhealthy poor old cripple burning scrap to pay for his hospital bills.


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## 4metals (Jun 3, 2012)

> By a afterburner, do you mean a return of the fumes back into the incinerator, to be burned again, similar to what is done with the exhaust from some cars? Or are do you mean a secondary burner that processes the exhaust from the incinerator?



An afterburner is a chamber that burns the smoke after it exits the primary burn chamber. Effective ones have enough volume to retain the smoke for 1 second, so it needs a volume equal to 1/60th of the CFM the incinerator uses. (Usually the burners blower CFM)

Usually a horizontal chamber over the primary burn chamber where the unburnt smoke passes into the upper chamber. One trick is to force all of the air to be burnt through a restriction like a donut where the flame from the secondary burner contacts the fume and effects a more complete burn. 

A very simple, but not always effective afterburner is basically a refractory chimney with gas burners in it, almost like using a gas melt furnace, a tall one, over the exhaust hold of the incinerator.


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## Geo (Jun 4, 2012)

wood could work, but it would have to be enough added to the incinerator on top of the material to last through the entire incineration. you cant open it to add more.that would restrict the amount of material you can work with at a time.

for example : if you were working with a 55 gallon drum. you need enough wood to last until all the boards was incinerated to white ash. (this is all hypothetical and my opinion and not fact) you would have one third boards and two thirds wood on top of them.

if you were working with the same drum with an after burner you could use the entire drum capacity for boards and the after burner would deal with the smoke and fumes.


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## qst42know (Jun 4, 2012)

Even if natural gas did cost more I can't think of one single time that natural gas ran out at the worst possible moment. No one can say the same for propane. 

If you do need to use propane due to your circumstances consider a back up plan such as a manifold system of more than one tank. 

I can't think of a worse application to come up short of fuel than during an incineration of a large volume of boards.


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## 4metals (Jun 4, 2012)

Burning the boards with wood is crazy because you are adding ash, of no value to ash of low or medium value in order to save a few pennies. The processed ash from PC Boards is always payable as a prepared sweep. Prepared sweeps are charged for processing in 2 ways, first by the pound in so the wood ash will cost you. Second the content of precious metal in the sweep determines the rate or payout. Dilution with ash is never wise.


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## jeneje (Jun 4, 2012)

4metal i have a question for you, if i build my incinerator, run the smoke through a afterburner and then through a pipe radiator to let the smoke cool down and then into the thump keg filled with water will this eliminate the toxin's. I will use propane for the fuel.
Thanks
Ken


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## 4metals (Jun 4, 2012)

Most incinerators eliminate the toxins by burning them. Some use an additional wet venturi scrubber but they do it to catch any valuable fly ash. 

Medical waste incinerators just use heat to completely reburn the smoke with the right temperature and retention time it is effective.


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## NobleMetalWorks (Jun 4, 2012)

4metals said:


> I have incinerated many pounds of circuit boards in my day and I have also burnt in the drums you have just described. But I would never burn circuit boards in the drums. Elastec makes them and they excel for brushes and wheels and flammable materials but without an afterburner I would not burn PCB's in them. http://www.elastec.com/portableincinerators/mediburn/videos/ Too much unburnt fume.
> 
> One reason I've lived as long as I have while actively refining is I strongly believe in controlling noxious fumes, they will age you fast! Be smart, use an afterburner at least 1800 F with a 1 second retention time.



I have a burn license in the county I live in, for the most part I am only incinerating plastics or other material that hold values, but are not PCBs. I strip the solder mask off PC boards, then depopulate them, then defoil them all in chemical plating tanks I bought from US Plastics.

http://www.usplastic.com/catalog/item.aspx?itemid=31501

I was using plastic storage containers but they take up so much flat space, and I am limited on the amount of floor space I can use for a chemical stripping tank. Plus the surface area of the tank is reduced, which will cut down on the amount of surface area that can capture dust or other particulates from the air, and they have a snug fitting lid for storage. The only problem I was having is how to retrieve the material stripped from the boards, I solved that issue by making a plastic strainer and plastic welding two arms to it so I can lower it and raise it from the two small ends of the tank.

Scott

Boards that look interesting, like the round test boards I posted awhile back, I totally strip then give to a guy I met who makes cocktail tables out of them. He mounts them, laminates them, and has buyers lined up to purchase them and gives me a percentage of the profit. It's not much but I rather see the material recycled and something made from them rather than incinerating them.


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## 924T (Oct 7, 2012)

SBrown,

Did you get your beer keg cyclonic incinerator up and running?

I'm looking at building a very small cyclone incinerator, out of a stainless steel stockpot,
and am curious as to how you determine the angle the air should be 'injected' at.

Or, is the injection angle even much of a factor?

I looked at the pictures page for the Elastec 'SmartAsh' burner, and the first picture is a line drawing
of their product-----------just guessing, but it looks like they're blowing the air in at maybe a 30 degree
angle.

Another question I have is Elastec has some kind of horizontal plate in the exhaust hole of the burner lid.
Does anybody have any idea what function that plate performs?

Cheers,

Mike


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## Geo (Oct 7, 2012)

924T said:


> Another question I have is Elastec has some kind of horizontal plate in the exhaust hole of the burner lid.
> Does anybody have any idea what function that plate performs.



more than likely, its part of the after burner. the gasses have to be slowed and heated to insure all the combustible gasses and heated carbon oxidizes. its a baffle of sorts.


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## 924T (Oct 8, 2012)

Geo,

That makes a ton of sense, about that plate slowing down the gasses.

I had no idea of its purpose; my best guess was that it had something to do with the cyclonic effect.

I wonder how critical the placement of it is?

Would it be considered to be a baffle?

Cheers,

Mike


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## etack (Oct 8, 2012)

reading through this I was wondering if you could put a catalytic converter on top of the furnace for the exhaust?

this would be similar to some wood stoves.

Eric


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## qst42know (Oct 8, 2012)

Catalytic converters are very sensitive to certain contaminants likely to be found in e-scrap (lead for example). I don't think they would last long.


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## butcher (Oct 8, 2012)

The catalytic off an automobile was designed for fairly clean burning engine exhaust, and where the exhaust heats the catalyst to begin with and the reaction of catalyzing the gases creates more heat, the wood stove flue normally would not make the catalyst hot enough to begin the reaction with flue gases, and it would very quickly soot up with creosote, clogging up your flue, which would then fill your house with smoke from the wood stove. As you loose the draft of hot air moving smoke up the stack pulling fresh combustion air into the firebox.


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## etack (Oct 8, 2012)

http://en.wikipedia.org/wiki/Wood-burning_stove#Catalytic_and_Non-Catalytic_stoves
https://www.google.com/search?q=Catalytic+smoke+stacks&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=nYpzUOujL8WuqAHj0oCIDQ&ved=0CFEQsAQ&biw=1600&bih=785#hl=en&tbm=isch&sa=1&q=buy+wood+stove+catalyst&oq=buy+wood+stove+catalyst&gs_l=img.3...113077.133952.1.134306.24.22.0.2.2.0.197.2581.5j17.22.0...0.0...1c.1.Gusf8EroFl4&pbx=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&fp=2312bab0b511f8c7&biw=1600&bih=785

This is not new technology I'm talking about. Its been proven over and over again. what would prevent it from being used here.

The best would be a gasification incinerator. Where the gas/carbons are returned to the flame to heat the material.

Eric


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## butcher (Oct 8, 2012)

The catalyst for a wood stove was made for wood stove.
The catalyst for the automobile was made for the automobile.
Modern wood stoves are designed with exhaust gas re-circulation where a secondary combustion chamber. This mixes exhaust gases with preheated fresh air and thus re-burns the smoke, similar to after burners this cleaner exhaust fumes can the pass through a wood stove catalyst, even this catalyst designed for a wood stove will not last long before it will need replaced, and depending how you use your stove or what type of wood you burn you would be better off taking the darn thing out and throwing it away. 

I did not say you could not have a catalyst that would work in a wood stove we have them around here, what I said is the automobile catalytic converter would not work, or would not work very well very long, you might adapt one for a few burns until you filled your house full of smoke.

Why do these stupid environmentalist think wood stoves are polluting, and then let our forest grow up with underbrush till they are a giant kindling box and then the whole country is on fire with these forest fire's filling enough smoke into the air to travel around the globes and then say it is a natural fire let them burn, until they start to burn up their pretty tourist traps which make them money?


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## etack (Oct 8, 2012)

butcher said:


> he catalyst for a wood stove was made for wood stove.
> The catalyst for the automobile was made for the automobile.



So if this was to be an option than it would have to be a catalyst used for polymers. 

thanks for your time Butcher

Eric


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## Geo (Oct 9, 2012)

i suppose a forced air system where the catalytic converter was in the combustion chamber itself might keep the catalyst hot enough to catalyze the CO2. the exhaust would have to leave the combustion chamber and then be forced back through the converter and finally to the exhaust outlet. it could be done using the same principle as the fume hood exhaust either using the venturi effect or a chemical resistant blower. thats a lot of trouble when a simple after burner will do the same thing though.


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## butcher (Oct 9, 2012)

I agree Geo.
All smoke is just incomplete combustion of fuel re-burning will eliminate smoke; NOx fumes are a little different story, as not everything in fuel or air burns.

Lets look at a fuel burning, for fire we need heat fuel and oxygen.
For fuel we will use common fuel of hydrocarbons, and air for oxygen.
The hydrocarbons contain hydrogen and carbon, the hydrogen does not burn, the carbon does.
In air we have mostly nitrogen with a smaller percentage of oxygen, the nitrogen does not burn the oxygen will burn.

So the oxygen and carbon form carbon monoxide (not enough air or incomplete combustion the carbon monoxide is a toxic gas), or if we provide enough air (3% excess air) then carbon and oxygen burn to form the safer carbon dioxide gas CO2.

The Hydrogen from the fuel joins with oxygen (when we supply enough air) to form water vapors in the flue gas or tail pipes of your car.

The nitrogen from the air that will not burn joins with oxygen to form NOx gas, not enough air we form nitrogen monoxide NO, with more air we form nitrogen dioxide NO2, when these gases leave our fire and the flue into the air NO mixes with air to form NO2, then NO2 mixes with moisture in the air to form HNO3 forming acid rain (actually nitric acid rain), exhaust gas re-circulation can help to lower the NOx, and catalyst in the automobile can help to put these back to nitrogen and oxygen.

Higher sulfur content in fuels such as diesel oil or coals, if flue temp is not hot enough the sulfur deposits can form in the flue (I have scrapped elemental yellow sulfur from boiler flues), if flue temperature is high enough the sulfur burns forming sulfur dioxide which when mixed with moisture in the air forms H2SO4 sulfuric acid rain.

After burners can help with smoke but they cannot help with the fumes that would need to be catalyzed or scrubbed to remove their ability to form pollution or acid rain


Proper air to fuel ratio and exhaust gas re-circulation can eliminate most all of the smoke and most of the dangerous pollutants and make the flue gas safer, but it will not eliminate all of the dangers.

Funny thing here but this pollutant we call acid rain, like the nitric acid rain, HNO3/H2O falls to the ground and gives plants the nitrates they need to grow, so in essence the pollutant becomes a fertilizer.


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## jonn (Dec 24, 2012)

Would the Das Escape Inline machine in the for sale section be just what the Dr. ordered? It vacuums fumes, pyrolyzes, oxidizes, reduces and neutralizes. The waste product is said to be clean water at the proper ph. Any thoughts ? :roll: 

It works off hydrogen, oxygen, and Lye. The lye looks like it's injected into the bottom port prior to the catch basin. Any solids go into a catch tray as well for easy removal. 

















Would this be perfect for the job :?:


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