How to turn plastic waste into diesel fuel cheaply

[imakebiodiesel]

`Piping in exhaust gases would work fine to purge the system initially but you probably wouldnt want an engine running throughout the whole process. Exhaust fumes contain a lot of water vapour which would mix with the fuel in the condensers.
A neater way to achieve the same result is to add a small amount of water to the waste plastic. This will boil long before cracking begins and evacuate any air in the reactor.
What Beyond Biodiesel proposes is to purge the whole system continuously with an inert gas.
While this is a good idea in a continuous feed system or any system where oxygen can enter, I dont feel that it is necessary in a closed batch system, however I could be wrong and it never hurts to be too careful.
The upper vessel in Jetijs's reactor , and in mine, is both a catalyst column and a reflux column. These two could be separated and this idea is explored earlier in this topic many pages back.

[Excalibur]

Exhaust fumes contain a lot of water vapour .

Yes, that's true. It would be better if the water was condensed out first?
The chart below shows the figures. Possibly worse than water is that diesel exhaust has an O2 of 10%
If the issues of exhaust gas can be overcome, it would be a great way of utilizing both nitrogen and CO2, both of which are abundant in exhaust gas and both of which are tipped as the gases to use.
To illustrate how effective exhaust gas can be, back in the early 70's when I was in the workshop, we routinely used car exhaust to purge fuel tanks in preparation for welding repairs. A simple hose was inserted into a gasoline engined cars' exhaust and its' gases were feed into the emptied fuel tank for several minutes. The welding work was completed with the exhaust gas still coming into the tank. To prove the point, the welding flame could be aimed directly into the tank without the vapors igniting! I wouldn't have believed it unless I'd seen it. After the boss initially demonstrated the technique I have used the method ever since.

N2 = Nitrogen
CO2 = Carbon dioxide
H2O = Water
O2 = Oxygen
CxHy (or Hx or HC) = Hydrocarbons
CO = Carbon Monoxide
NOx = Nitrogen oxides
SO2 = Sulphur dioxide
PM = Particulate matter

[mercedes 308]

I do not think the use of PTFE seals anywhere in the system, is advisable due to fire risk. Beyond biodiesel says hes thinking of using as condenser seals. And states that set up should be away from buildings, because it will catch fire. The pyrolysis of PTFE is detectable at 200 °C (392 °F), and it evolves several fluorocarbon gases. At higher temperatures it can release Hydrofluoric acid.

Taken from wiki "Health & safety

Hydrofluoric acid is a highly corrosive liquid and is a contact poison. It should be handled with extreme care, beyond that accorded to other mineral acids. Owing to its low dissociation constant, HF as a neutral lipid-soluble molecule penetrates tissue more rapidly than typical mineral acids. Because of the ability of hydrofluoric acid to penetrate tissue, poisoning can occur readily through exposure of skin or eyes, or when inhaled or swallowed. Symptoms of exposure to hydrofluoric acid may not be immediately evident. HF interferes with nerve function, meaning that burns may not initially be painful. Accidental exposures can go unnoticed, delaying treatment and increasing the extent and seriousness of the injury.[8]

Once absorbed into blood through the skin, it reacts with blood calcium and may cause cardiac arrest. Burns with areas larger than 25 square inches (160 cm2) have the potential to cause serious systemic toxicity from interference with blood and tissue calcium levels.[9] In the body, hydrofluoric acid reacts with the ubiquitous biologically important ions Ca2+ and Mg2+. Formation of insoluble calcium fluoride is proposed as the etiology for both precipitous fall in serum calcium and the severe pain associated with tissue toxicity.[10] In some cases, exposures can lead to hypocalcemia. Thus, hydrofluoric acid exposure is often treated with calcium gluconate, a source of Ca2+ that sequesters the fluoride ions. HF chemical burns can be treated with a water wash and 2.5% calcium gluconate gel.[11][12][13] or special rinsing solutions.[14][15] However, because it is absorbed, medical treatment is necessary;[9] rinsing off is not enough. Intra-arterial infusions of calcium chloride have also shown great effectiveness in treating burns.[16]

Hydrogen fluoride is generated upon combustion of many fluorine-containing compounds such as products containing Viton and polytetrafluoroethylene (Teflon) parts

Polytetrafluoroethylene - Wikipedia, the free encyclopedia
Hydrofluoric acid - Wikipedia, the free encyclopedia

Many people doing this come from less well off countries, and would not have available the medical expertise to deal with Hydrofluoric acid burns.

[Beyond Biodiesel]

I do not think the use of PTFE seals anywhere in the system, is advisable due to fire risk. Beyond biodiesel says hes thinking of using as condenser seals. And states that set up should be away from buildings, because it will catch fire. The pyrolysis of PTFE is detectable at 200 °C (392 °F), and it evolves several fluorocarbon gases. At higher temperatures it can release Hydrofluoric acid.

PTFE are good to 500F (260c) above that use some other seal system.

[gerardo]

To mister jetics
my set up is to get diesel from used motor oil.
then in the burner after 4 hours of work a buildup is formed I think is carbon and metal in the oil I think if the oil gets centifuged before entering the kiln I can solve that problem.
then 200 litres are obtained in 14 hours, may be if I go 400 celcius instead of 300 the time of work can be shotened.
one more thing is a smell like sulfur very strong in the final product after the condenser, I hope that after filtering with some other type of fitering I can lower that smell or how can this smell be lowered.
What do I do? what do you think?
regards from mexico.

[Beyond Biodiesel]

To mister jetics
my set up is to get diesel from used motor oil.
then in the burner after 4 hours of work a buildup is formed I think is carbon and metal in the oil I think if the oil gets centifuged before entering the kiln I can solve that problem.
then 200 litres are obtained in 14 hours, may be if I go 400 celcius instead of 300 the time of work can be shotened.
one more thing is a smell like sulfur very strong in the final product after the condenser, I hope that after filtering with some other type of fitering I can lower that smell or how can this smell be lowered.
What do I do? what do you think?
regards from mexico.

gerardo, I too am distilling WMO to turn it into diesel fuel. Do keep in mind that even after distilling WMO it will still be too viscous to use as diesel fuel, unless it cracks into diesel fuel. So, I add gasoline (petrol) to my WMO to turn it into diesel fuel.

My goal in distilling WMO is just to get rid of the coke, which you observed above. Coke is made up of mostly ash and carbon. The ash is mostly metals, like silica. The coke will be left behind in your retort, so that when you burn the WMO the coke will not be left behind on your injectors.

Raising the temperature of your retort will not reduce the coke left behind in it. And, it will also not do any more for distilling your WMO, but it could lead to boil-over, which could force dirty WMO into your condensate. To distill WMO all you need is less heat, like 500F (260c).

So, if you can avoid boil-over, then there should be no reason to filter your condensate, and doing so will not eliminate the smell of sulfur in your resulting fuel.

Centrifuging your WMO before putting it into the kiln is just a waste of time, because distillation is far more efficient at removing contaminants than Centrifuging.

[mercedes 308]

catalyst in reflux

Hi all, regards catalyst in reflux, as anybody used Expanded clay aggregate as used in hydroponics and pond filters.?

The clay pellets are inert, pH neutral
The clay is formed into round pellets and fired in rotary kilns at 1,200 °C (2,190 °F). This causes the clay to expand, like popcorn, and become porous. It is light in weight, and does not compact over time.
Does the size of the media effect its suitability. is larger better due to easier gas flow?

[fibuslitero]

I have used it recently but first I had to let it dry a bit because it absorbs a lot of water (that is not bad at all but we need empty "microcaves").

I have to make more tests but I think pumice stone works much better, at least in my case.Maybe a combination of expanded clay and pumice will be the point.

Hi all, regards catalyst in reflux, as anybody used Expanded clay aggregate as used in hydroponics and pond filters.?

The clay pellets are inert, pH neutral
The clay is formed into round pellets and fired in rotary kilns at 1,200 °C (2,190 °F). This causes the clay to expand, like popcorn, and become porous. It is light in weight, and does not compact over time.
Does the size of the media effect its suitability. is larger better due to easier gas flow?

[mercedes 308]

gas storage

@ dutchdivco
Did you manage to sort out your gas storage problem ?

[mercedes 308]

I have used it recently but first I had to let it dry a bit because it absorbs a lot of water (that is not bad at all but we need empty "microcaves").

I have to make more tests but I think pumice stone works much better, at least in my case.Maybe a combination of expanded clay and pumice will be the point.

Its sort of similar in construction.

File:Hydroton.jpg - Wikipedia, the free encyclopedia

[Beyond Biodiesel]

Hi all, regards catalyst in reflux, as anybody used Expanded clay aggregate as used in hydroponics and pond filters.?

When using a catalyst it will quickly become saturated with free-carbon, so it will have to be regenerated every time you run another batch of whatever it is you are cracking.

If this is acceptable, then the easy way to clean your retort, and regenerate your catalyst, will be to flush the retort and reflux column with O2 after all volatiles have been evaporated off. The carbon coating on the retort, and on the catalyst particles will be burned off and turned into CO2.

The process of regenerating catalyst produces so much heat that it can power the retort. The real problem will be in not melting down your whole apparatus in the process, so turn off the heat, and introduce O2 slowly over time, while monitoring the temperature of your retort.

You will find that you can control the temperature of your retort just by regulating the flow of O2 into it after the heaters have been turned off. What you do not want to happen is have the temperature rise above 1200F (650c), or drop below that during the regeneration cycle.

When the temperature begins to drop during the O2 burn cycle is an indicator that C has either been consumed, or you are not putting enough O2 in to power the regeneration cycle.

[Marso Green]

Regenerating the catalyst

When using a catalyst it will quickly become saturated with free-carbon, so it will have to be regenerated every time you run another batch of whatever it is you are cracking.

If this is acceptable, then the easy way to clean your retort, and regenerate your catalyst, will be to flush the retort and reflux column with O2 after all volatiles have been evaporated off. The carbon coating on the retort, and on the catalyst particles will be burned off and turned into CO2.

The process of regenerating catalyst produces so much heat that it can power the retort. The real problem will be in not melting down your whole apparatus in the process, so turn off the heat, and introduce O2 slowly over time, while monitoring the temperature of your retort.

You will find that you can control the temperature of your retort just by regulating the flow of O2 into it after the heaters have been turned off. What you do not want to happen is have the temperature rise above 1200F (650c), or drop below that during the regeneration cycle.

When the temperature begins to drop during the O2 burn cycle is an indicator that C has either been consumed, or you are not putting enough O2 in to power the regeneration cycle.

This may sound like an oversimplification, but would it be possible to remove the C by Reduction, (which is the reverse of Combustion) by heating the catalyst chamber while running CO2 and H2O through it? The result would be H2 + CO, which is combustible. In fact, if clean enough, it can run a spark ignition internal combustion engine, but for the purpose of practicality, the gas can be flared off. I'm not experienced in this field, so please feel free to critique this idea, and thank you all for this great forum


Marso Green

[imakebiodiesel]

This is an important area we need to discuss. The clay catalysts many of us have been trialling have very short active lives and a lot of catalyst is needed to produce a significant amount of fuel. In my own clay catalyst mix about 100 gms of clay will only produce about 2 litres of usable fuel before "coking".
As I see it there are three possible solutions to this problem.
1 Find more efficient catalysts.
2 Regenerate the catalysts.
3 Use catalysts that are so cheap than they can be disposed of after one use.

[fibuslitero]

The three points are important certainly...
Maybe what is tiring is opening, emptying and recharging the reflux module again and again but our setups are humble and limited, at least mine... .
I was thinking about some kind of interchangeable reflux module between plastic loads.
For easy and fast pipe removals this kind of clamps are needed :
Heavy Duty Clamps
The japanese from Blest company use them as I saw in their videos.

This is an important area we need to discuss. The clay catalysts many of us have been trialling have very short active lives and a lot of catalyst is needed to produce a significant amount of fuel. In my own clay catalyst mix about 100 gms of clay will only produce about 2 litres of usable fuel before "coking".
As I see it there are three possible solutions to this problem.
1 Find more efficient catalysts.
2 Regenerate the catalysts.
3 Use catalysts that are so cheap than they can be disposed of after one use.

[Excalibur]

one more thing is a smell like sulfur very strong in the final product after the condenser, I hope that after filtering with some other type of fitering I can lower that smell or how can this smell be lowered.

My fuel, cracked from mineral oil also had a strong sulphur like smell so I took a sample to an acquaintance who works at a university. In his opinion it wasn't sulphur. He thought maybe phenol.
Google tells me that phenol is an aromatic hydrocarbon.

Testing the fuel in the Toyota tomorrow. Will see how it runs. Plus whatever other tests I can think up.