How to turn plastic waste into diesel fuel cheaply

[imakebiodiesel]

Sorry, I forgot to ask, when you say PS I assume you mean polystyrene, why is it bad?

[kaguar]

When polystyrene is cracked you get styrene (monomer, a bit of dimer and even less of trimer). Theoretically it is an excellent fuel - very low freezing point and moderate boiling pint, burns well. BUT styrene monomer repolymerizes so quickly when heated just slightly - turning back to polystyrene. During that process styrene looks like glue. Now, in diesel engines you have very high pressures and temperatures between the pump and the injectors - far more than enough to rapidly repolymerize styrene which is then returned to the tank containing styrene glue and then pumped again through the system. I know this for sure as I had to clean three times injectors on my DCi engine and it was always after I had PS in my waste feed.
Fuel from PP and PE will repolymerize as well but never so quickly as from PS. PS is a complete disaster. Every time I had PS in my feed the fuel smelled like hell. By the way styrene attacks PS, ABS and any other plastic out there that has styrene for its building block. ABS should be avoided in your feed as well.
All this is right if we use a simple thermal cracking. If we are to use catalytic cracking it is a completely different story, PS could be freely used.
Cheers

[islander]

the book free to download here

Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels by John Scheirs

[Jetijs]

Hi all.
Today I finished building the refluctor part of my small unit. I could not weld it on the reactor lid, because there was simply not enough space there, I need some space there for WMO inlet and the temperature sensor, so I put it on a 1" pipe some distance apart from the reactor. The refluctor will of course be insulated so that the heat maintains fairly high for the denser parts of the hydrocarbon chains to condense and flow back for further cracking. I made the refluctor with a lid and flange just as thereactor itself, this will allow me to open it for cleaning and putting in various catalysts. Here are the pictures:





I am sorry for not answering your questions on time, I am very busy and in the mean time I am very lazy. Will do that shortly.

[Jetijs]

Jetijs, I have most of the components gathered up to build my reactor. Im going for a design very similar to the one you showed recently in photographs. In fact i may have bought the heater bands from the same ebay seller.
I have a question about the v shape seal you use on the lid. Is the male v narrower and taller than the female groove, or are they exactly the same?

I make the channel with a V shaped turning tool and then use the same tool to make the outward groove on the lid. The outward groove is a bit wider than the channel, but it has the same angles and a flattened top.
Hope this helps.

[imakebiodiesel]

Many thanks, thats exactly what I needed to know.
Your reactor and refluxor look very professional. What kind of baffle material are you going to use? I have used glass marbles in a reflux column for methanol recovery, but im not sure they would be suitable for such high temperatures. Perhaps ordinary steel nuts and bolts might work.

[Jetijs]

I thought of using iron turnings and the bottom of the refluktor and then a mesh containing the catalyst on top of that. I am still too far away from real testing. I will need a condenser now. At first I though of using only one condenser cooled to room temperature. I will separate the gasoline and diesel from the liquid fuel later using a modified water boiler at temperature around 150 degree celsius. All the gasoline will evaporate and diesel should remain. At least I hope so

[imakebiodiesel]

From what I have read so far, iron turnings may be a catalyst themselves. A friend who has designed several stills for industry suggested using short 10mm pieces of stainless steel pipe 10- 20mm diameter. These would act in the same way as the rachid rings industry uses but would be large enough not to be blocked by wax or soot.

[kaguar]

If you are planing on using any catalist think first of a good cyclone in front of it which will remove carbon from the stream and prevent its blockage. In this case iron will just remove chlorin and suphur from the stream. In this sort of pyrolysis you need zeolite or delaminated clay as a catalist. So far only those things worked as they act as molecular sieves passing through only molucules of certain sizes which are in range of disel and petrol. Now, if you have a good cyclone and use catalyst in a continuous proces it will be almost the same as you dont have them due to catalyst getting covered in carbon very quickly. You will need a catalyst regenerator and for every kg of fuel you get you need 5kg of the catalyst.
This is how it should be done but I`m still in search of some more simple method (if it exists at all). Cheers

[islander]

Hi kaguar

Your experience seems very valuable. Do you already use small cyclones ? But an observation : why use cyclones if some of us get du successfully yellow clean fuel at output without using that.

Chinese claim they sell catalyst designed for plastic/wmo diesel making. I buy to them. If someone wants, i could help.

Something Like 1 kg catalyst for enormous qty of fuel

Kaguar, is it possible to Know More about tour works ?

I would be very interested in !

I Am building the verrall concept. Not finished, needs parts. But I guess i Will have the oxydation/stability issue Like I had with my first set up

[kaguar]

OK, here is my baby
I`m constantly upgrading it, so it changes its outlook every now and then. Description:
Pipe on the left - constant supply of wmo
reboiler - there is a hole in the middle and that is where I keep my heater. Firstly I had it outside as jetijs but then I found it for much better solution to have it inside the reboiler - it is more energy efficient. This way you can use only 2KW heating element for the thing to operate. I always build my own heating el.
The red thing on the right is a swirl tube/reflux. Plumbing guys out there will easily recognize the elements it`s built of. After 12 hr of operation this part gets nearly blocked by soot.
Cheers

[CRMoore]

3rd try

I may be repeating but believe I failed to post (belated) reply to posts I missed when I used the "last page" option.

Summation/clarification/agreement-saturation occurs when a carbon chain(C) has added hydrogen(H) to all C-C multiple bonds. When C-C bonds are broken a new bond is made to each C; with Hs, other Cs (repolymerization or ring formation) or other elements (eg oyygen) or forming muliple C-C bonds at the (new) chain ends. To stablize fuel formation H could be added. This might be released by Ca(OH)2 reacting with H2S; I just wasn't focusing on this. Plastics are generally sulphur free though or so I believe(d); is it the WMO?

[imakebiodiesel]

Thanks for the reply, CRMoore. Motor oil may contain up to 0,5% sulphur, thats the limit in the EU. Some PE and PP can have up to 1% sulphur compounds which I believe is to help colour consistency and fastness. So there is probably a small amount of sulphur present in a wmo/pp/pe mixture.
Am I correct in saying that a metal catalyst such as nickel, palladium or platinum require hydrogen from some other source whereas a zeolite/ mineral catalyst supplies its own from within its crystalline structure?

Your reactor looks like a serious piece of gear and has obviously done a lot of processing. Im in the process of building my own reactor so I have a couple of questions. What would be a typical temperature at the reflux/swirl pot. Is it only wmo you are using or is it a mix of wmo and molten plastics? Is your reflux pot filled with a baffle material?

[islander]

Tanks, Kaguar

I have a question : why your output pipe is blocked by soot, means your output syngaz is full of smoke/dust, but you get clear output fuel ?

My firt attempt to use my fuel, after cleaned it with centrifuge, was injector very disturbing : my injectors keep not functionning well, got enormous smoke even returning at commercial diesel

[kaguar]

imakebiodiesel,
yes, this particular reactor has been working for me for the last year and a half and I`ve been upgrading it constantly.
I constructed the reflux/swirl for the present reactor operating conditions so it can be kept on 270 C aproximately. I`m in process of upgrading the reactor which means I`ll have to change the reflux unit as well.
I use about 10% of plastic in the feed, the rest is wmo.
The reflux is filled with iron wool at the present. If you or anyone else has better idea I`m open for suggestions.