How to turn plastic waste into diesel fuel cheaply

[otpadnoulje]

hi there,

sorry to ask I know it has been discussed somewhere on the thread before. what is the diesel yield for Waste Motor Oil per litre
? I have found a source of this locally.

50-70%

[Beyond Biodiesel]

I dont know if Neil has tried cracking plastics without a catalyst but I have on several occasions. The picture below shows the product of thermal cracking only. The Molecule length has been cracked from roughly C1200 (PE average figure) to about C50.

Here is the product of the same plastics processed at the same temperature ( 390c but with my latest catalyst. This has an average molecule length of C14 so in fact the improvement is less than 10% but I think you will agree that the difference is quite important.

Thank-you, imakebiodiesel, for posting your very useful findings and photos. I have no problem with recycling the heavy fractions back into my retort each time I reload it. So, for me, I am happy not to use catalyst in my process, even though I have had more experience with running cat cracking units than most of the people on this forum.

[Asad Farooqui]

CLAY catalyst

Just an adjustment to the yield figures for pyrolysis of plastics. Currently I am getting 55% diesel, 28% kerosene,7% gasoline,4% gas and 6% char. Obviously this figure will vary with different catalysts and temperatures. I cant comment on the yield for wmo as I have not tried it.

Long time Hello IMBD;
I hope you must be using vapor phase catalyst . I guess your yield per liter around 70%.
Which catalyst you tried ???

Did you try clay catalyst mixed in liquid phase only ???
I found the OIL yield increase upto 85-90% .
Clays are best for producing more of C18-C25 Diesel type fuel & less Gasoline.

Lastly what is the RON value of your diesel fuel ???

[otpadnoulje]

Did you try clay catalyst mixed in liquid phase only ???
Hello,Asad Farooqui! Nice to see you again!

Could you better describe your procedure, please. Is the clay ground into powder. What is the percentage of
clay-oil. Does the thickening of diesel. Do you use any pour point depressant, prevent wax crystals?

Thanks!

[arunkumarls]

Hi bugler.
Look at this picture:

http://www.emuprim.lv/jetijs/plog-content/images/jeti-stuff/degviela-no-riep__m/zupa-006.jpg

there you can see the cut slots in the bricks that house the coils. They are cut in the following configuration:


Yes, you can use single phase current and 2kW of power should be enough for about 20 liter reactor container. You can use either one heating element rated for 2kW or two 1kW ones in parallel. The voltage used is mains power so 220v in Europe and 110v in US. I don't know exactly the specs of the nichrome wire, but something around 1-1.5mm diameter wire should be used, you just need to get such a wire and measure the resistance of it for say a meter, then based on your power needs, you calculate the total length of the wire. For example, if the wire has say 30 Ohms of resistance per meter and you need it to work at 1000w of power, then at 220 volts that would be 4.54 Amps, so you need to get the wire so long that its resistance will limit the current to 4.54A. So if the resistance per meter is 30 Ohms, then at 220 volts 7.33A of current will flow through that wire, that means 1.6kW, that is too much, in order to get 1kW of power we need to increase the wire length till the total resistance of the wire is 48 Ohms, that then would be around 1.6 meters of wire. Hope this helps.

Here is how the electrical circuit would look like in your case of single phase current:


I use digital temperature controller, you can get them on ebay for about 40$, something like this:


The relays are of solid state type, like this:

These are about 15$ a piece. The temperature controller monitors the temperature in the reactor and sends 12v impulses to the bottom contacts of the solid state relays that turns them on and off so that the needed temperature is maintained.
A thermocouple is a temperature sensor, this is the thing from where the temperature controller gets the data from, it is a small metal piece with two wires coming out of it, the metal piece is put where the temperature needs to be monitored and the wires are connected to the temperature controller. It looks something like this:

http://www.deltat.com/uploads/images/content/Thermocouple_for_plastic.JPG

Here you can see the metal cage upside down:

And here you can see it in the whole assembly:


This cage does not let the reactor chamber touch the bricks and coils. I think this should be easy to get from the pictures.

I hope this helps.

we are about to make your assignment as our final year project.and we need assistance.so you please help us

[Asad Farooqui]

CLAY catalyst

Did you try clay catalyst mixed in liquid phase only ???
Hello,Asad Farooqui! Nice to see you again!

Could you better describe your procedure, please. Is the clay ground into powder. What is the percentage of
clay-oil. Does the thickening of diesel. Do you use any pour point depressant, prevent wax crystals?

Thanks!

Hello Old timer;
otpadnoulje, Nice to hear from you .
I experimented with many clays & most of them works well .
You can select from China-clay, Bentonite & Montmorelonite clay in powder form, which ever is cheaper .
Clay % = 10-16% of the plastic .
No wax formation even after 03-months of shelf life .

If you can activate your clay around 400 celcius it will decrease the pyrolysis time significantly . I have experienced the residence time cut/Halfed in some cases.
S.gravity of crude oil = 0.784 (more diesel like )
From 02-kg PE-plastic = 1.913 liters crude oil yield= (yield By volume=95%)

I have seen reports of people developed Zeolite based simple catalyst at home which can convert 90% of the liquid fuel into gasoline type .

I have gathered a big list of potential catalyst which do wonders & testing them one by one .

A friend of mine has developed a catalyst to pyrolyse the MIXTURE of Bio-mass like saw-duct, rice husk with waste plastics, pyrolysed into diesel type fuel.


Beyond Bio-diesel,
Kindly stop saying that catalyst do nothing
OR you are the only one on this forum who has big-experience in working with catalyst .
With your wast experience working with catalyst can you recommend a catalyst for the above mixture OR a catalyst for processing ALGEA+Plastics (50/50)???

Most of the New-comers are misguided by your FALSE statement & Iam sorry to say that you keep on insisting about your point of view .

This forum should be the place where we should encourage everyone to keep on experimenting with new Ideas & catalysts & keep this forum alive with HEALTHY debates.

[CRMoore]

[QUOTE=Asad Farooqui;205218]Hello Old timer;
otpadnoulje, Nice to hear from you .
A friend of mine has developed a catalyst to pyrolyse the MIXTURE of Bio-mass like saw-duct, rice husk with waste plastics, pyrolysed into diesel type fuel.

This sounds wonderful-perhaps one could mix paper even cloth into the mix. One concern that I heard from another discussion group was that catalysts can break down creating fines to be filtered. Another fuss factor that might reduce the desirability of catalysts especially on the small scale.

I still am waiting for an affordable (~$5,000 US) Blest Be-h size unit (1-5 L/batch) to be offered in the US. For all the feel good videos Blest does not seem to be interested in this market. Like composting, worm boxes, pellet making and burning I see this as enabling an individual/neighborhood to make (better) use of its waste.

[imakebiodiesel]

Like you Asad I have been testing various clays and minerals. Clay in any form will have some catalytic properties but some are very short lived. Bentonite and montmorillonite are better and less is needed. Fired clays will have reduced activity, producing less gas and more heavy diesel fractions.
I have tested over 40 materials and mixtures.
I should be honest at this point, it is my intention to develop and sell a disposable catalyst for anyone wanting to convert plastics into fuel. I am very close to having such a product ready for the market. 1kg of my latest mixture will convert 100 kg of plastic with no waxing and very little degradation in colour.
My catalysts are for gas phase use only. I have had no success with liquid phase.
For gas phase use the clay must be formed into small blocks about 12mm square. These are loaded into the reflux column and preheated. A finely ground powder catalyst would offer more surface area but might cause a blockage which could be dangerous.

[imakebiodiesel]

Asad I missed your question about RON value. My fuel has been analysed at Waterford Institute of technology by gas chromatograph and mass spectrometer so I have a lot of data about its make up but unfortunately they do not have a test rig to determine the cetane value. Cynar plc who make 50,000 litres of diesel per week from plastic waste, claim a cetane value of their fuel of 64 which is very high, but I cannot confirm that.
I am concentrating on the production of fuel oil ( kerosene type) as many recent cars here use common rail type injection systems that are very sensitive to variations in fuel quality, and also very expensive to fix. Kerosene burners, as fitted to most home heating systems in Ireland on the other hand, are simple devices, and can burn a wide variety of fuels.

[Asad Farooqui]

CLAY catalyst

My catalysts are for gas phase use only. I have had no success with liquid phase.
For gas phase use the clay must be formed into small blocks about 12mm square. These are loaded into the reflux column and preheated. A finely ground powder catalyst would offer more surface area but might cause a blockage which could be dangerous.

Hello IMBD ;
Powdered-Clays Should be used as a liquid phase catalyst, NOT Gas phase .
clays are cheap & they end up with the char after one batch.
If you calculate the oil-yield increase & no need to re-crack the wax, it becomes feasible & time saving .
Another advantage in a liquid phase catalyst is the drop in temperature from 470 down to around 380-400 celsius. This advantage you won't get for a gas phase catalyst .

The catalyst you are working on is I guess is a natural-Zeolite type which could be re-generated after few batches???

What I have worked out is Zeolite based catalyst have a honeycomb structure which helps Longer chain C-C bonds to be chopped-Off into smaller bonds .
So the end result will be more kerosene type fuel upto B.P-275 Celsius & less Diesel fraction .

[imakebiodiesel]

I understand the powdered clays are suitable for liquid phase use, the clay blocks I mentioned are for use as gas phase in the reflux column. I can see the advantage of being able to clean out both the char and the clay in one operation.
Im a bit puzzled by your experience of required temperatures. In my gas phase system cracking begins vigorously at 375C, towards the end of the batch when the flow slows down I raise the temp to 415C. I have never had my reactor at 470 or even close to it.
I have been experimenting with various methods of purging and would appreciate your thoughts.

Nitrogen gas purge. From the moment the heating starts until the reactor has cooled fully a steady stream of N2 is fed into the reactor and leaves through the bubbler.
Pros. Very safe, requires no special management.
Cons. expensive and in some regions difficult to obtain. The N2 dilutes the hydrocarbon gas and makes it difficult to use.

Propane Gas purge. Like the N2 purge the gas flows throughout the process.
Pros. Safe, the auto ignition temperature of propane is 470C, well above the temp in the reactor. The propane/ hydrocarbon gas mixture can be used as a heat source, effectively providing purge gas for free.
Cons. As a heat source propane requires some management and cannot easily be controlled automatically

Kerosene and gas bag purging. This is the method I use in my small reactor. 200 ml of kerosene is added to the 1kg of waste plastic. Before cracking begins the kerosene has boiled and been collected in the condenser purging the system of air. Above 300C all gas output from the bubbler is collected in a plastic gas bag. When the reactor cools down a partial vacuum is formed and some of the gas is drawn back into the reactor instead of air.
Pros. cheap (like me) and reasonably safe.
Cons. Requires a bit of management.

[thissideup]

Hello IMBD ;
Powdered-Clays Should be used as a liquid phase catalyst, NOT Gas phase .
clays are cheap & they end up with the char after one batch.
If you calculate the oil-yield increase & no need to re-crack the wax, it becomes feasible & time saving .
Another advantage in a liquid phase catalyst is the drop in temperature from 470 down to around 380-400 celsius. This advantage you won't get for a gas phase catalyst .

The catalyst you are working on is I guess is a natural-Zeolite type which could be re-generated after few batches???

What I have worked out is Zeolite based catalyst have a honeycomb structure which helps Longer chain C-C bonds to be chopped-Off into smaller bonds .
So the end result will be more kerosene type fuel upto B.P-275 Celsius & less Diesel fraction .

So, just to clarify, you do not use a gas phase catalyst all all, only liquid phase, ( clay added to your plastic feedstock ) ? do you also use hydrated lime as some have mentioned earlier?

[Beyond Biodiesel]

For those who asked up thread how to regenerate a catalyst. It is quite simple to regenerate a catalyst after cracking hydrocarbons. Just bring the catalyst up to 1200F (650c) in the presence of O2 and it will burn off the carbon in the catalyst matrix, so that it can be used again. It is also a great way to clean the coke out of your reaction vessel. And, the ash left over in the retort might just act as a catalyst.

Also, diatomaceous earth is a common swimming pool filter additive, and it so happens to be an excellent catalyst, so if you are having trouble locating a catalyst, then most grocery stores in the USA sell diatomaceous earth for about $5/small box, which should be enough catalyst for a 55 gallon (200L) load.

However, I think the use of a catalyst is unwarranted in small scale pyrolysis units as we are discussing here.

[jfdube]

Amen!

I think half of you need to get back to basics, and focus on the colaborative effort to perfect this process. Debating the economics, future political opposition or apocolyptic feasability of the process will only serve to discourage. I have a brother that thinks like that, for every great idea he has, he also has two great reasons why ''it wont work''. You will be amazed at how much you can accomplish by simply getting up in the morning and dealing ONLY with the problems that present themselves during that day. You'll find that only a fraction of the road blocks that you assume will stop you actually present themselves during the course of your venture, provided you wake in the morining with the mind set to achieve and succeed. I suggest you take a moment read about the history of the light bulb before posting why ''it wont work''.

[jfdube]

Thank you ALL sooooo much for all the informations, but...

...as a visual type learner, I (as many others) could really benefit from more of your pictures, diagrams, schemas and other visual stuff as a source for inspiration, food for brain or whatever you may call it.

It's been said that it's nearly impossible to have one single definite design but after reading ALL the posts in 2 days (ADHD hyperfocused style), I know there is a lot more to be seen even with all the quality infos.

J-F from Quebec City, Canada