How to turn plastic waste into diesel fuel cheaply

[wheels]

I have a machine burning waste plastic shreds.When we reach temp of 285*c we produce product of 0.78 on hydrometer.
We increase temp by 1*c and it starts to wax when cooled too 20*c.
Just cant get to the 0.80 on hydrometer to clear as diesel.
Any idea's?

Are there any updates rozier. We are all interested in knowing how you have got on.

For others reading, you will note that often times there are many varied answers given. Many answers seem conflicting. This is because there really are so many variables. Size of Plant, Heat energy input, type of plastic or WMO, speed the Feedstock is processed at, design of reflux, is a catalyst used and what is used as the catalytic medium. There is no one clear definitive answer, unless each and everyone has the exact same plant in every aspect and the exact same Feed Stock. Even commercial plants vary all over the world, as each company tries to find the best most efficient means of producing Fuels from Plastic.

[Excalibur]

Who's out there??

I'm in the planning stages of a new continuous feed retort/reactor. I want the new plant to be better automated. Basically I'll review everything I've learnt and devise a simple unit. With diesel prices still very low there is no urgency.
Will be be updating the blog with progress.
Thanks!

[rozier56]

rozier56

Pls remind me why i cant make my retort out of stainless steel?

[Excalibur]

You need a heat resistant type.
Grade 309 looks like a good candidate. More study required though.
http://www.aksteel.com/pdf/markets_p...data_sheet.pdf
Hope this helps.

[rozier56]

rozier56

Thank you.
Others recommended are a516/70 and 3cr12 plus vrn400.
Had a collapsed fire wall,made of 6mm mild steel.RETORT made of same material and no problem on inspection.
This machine fired 5 days/ week. Lasted for one year.

[Excalibur]

Rozier,
Good to know your retort held up for some 250+ firings. I'm guessing that the firewall was placed to reduce overheating of the vessel? I suppose you've made the firewall sacrificial?
With 250+ firings you must have learnt quite a lot about what's working well, what's giving problems and found some nice solutions. Are you willing to share any pics or info so the forum community can benefit?
Thanks.

[wheels]

Thank you.
Others recommended are a516/70 and 3cr12 plus vrn400.
Had a collapsed fire wall,made of 6mm mild steel.RETORT made of same material and no problem on inspection.
This machine fired 5 days/ week. Lasted for one year.

Resistance to oxidation, or scaling, is dependent on the chromium content in the same way as the corrosion resistance is. Most austenitic steels, (304 and 316) with chromium contents of at least 18%, can be used at temperatures up to 870°C. However, be aware that 316 can be prone to cracking.
Grades 309, 310 and 2111HTR (UNS S30815) will withstand even higher temperatures.
Plus the ferritic grade 446 - this has approximately 24% chromium, and can be used to resist scaling at temperatures up to 1100°C.
304/316 = 870 degC
309 = 980
310 = 1035
446 = 1100
2111HR = 1150

The issue is cost of making a vessel of these materials, against how long you get from a Mild steel Vessel and how long it lasts. Mild steel is far cheaper when I was using a vessel for a retort in the earlier days, I decided to stick with mild steel and just replace it, rather than a far greater cost of a SST vessel.

[Heartburn]

Synopsis available somewhere ?

Hey guys,

Has anybody posted a synopsis of all the parameters discussed here ? I've read the thread and didn't thing of writing everything down as I read.

I want to build a unit with a custom control panel. Building to control panel is a lot of work so If I can save a few hours by not having to go through all the posts a other time it would be very helpful.

Thanks in advance,

hb.

[sunilkm153]

Resistance to oxidation, or scaling, is dependent on the chromium content in the same way as the corrosion resistance is. Most austenitic steels, (304 and 316) with chromium contents of at least 18%, can be used at temperatures up to 870°C. However, be aware that 316 can be prone to cracking.
Grades 309, 310 and 2111HTR (UNS S30815) will withstand even higher temperatures.
Plus the ferritic grade 446 - this has approximately 24% chromium, and can be used to resist scaling at temperatures up to 1100°C.
304/316 = 870 degC
309 = 980
310 = 1035
446 = 1100
2111HR = 1150

The issue is cost of making a vessel of these materials, against how long you get from a Mild steel Vessel and how long it lasts. Mild steel is far cheaper when I was using a vessel for a retort in the earlier days, I decided to stick with mild steel and just replace it, rather than a far greater cost of a SST vessel.

Good explanation by wheels ss 304 is sufficient for retort vessel even professional processors opt for it no need to think about any other option

[Excalibur]

In the interests of safety, the question has to be asked..
If (for example) 304 stainless was used for the retort vessel, does the applied flame temperature have to be limited to 870°C at the point of contact?

[wheels]

In the interests of safety, the question has to be asked..
If (for example) 304 stainless was used for the retort vessel, does the applied flame temperature have to be limited to 870°C at the point of contact?

No. That temperature is still well below any form of Failure. Metling point is ruffly twice the operating temp. Simply, 870 is a temp at which corrosion will take place. However, SST is only Stainless because of the presence of oxygen. So depending on the type of heat source, the way it is applied and the oxygen within the heating box, Corrosion rates will vary slightly between peoples designs.

[Hoddamdg11]

Fuel from Mixed Plastic to Be Tested in Marine Engines

FYI
see article at:
Fuel from Mixed Plastic to Be Tested in Marine Engines | Engineering360

[wheels]

FYI
see article at:
Fuel from Mixed Plastic to Be Tested in Marine Engines | Engineering360

While that is good, I am not sure if it will be practical. The reason being is the volume of Fuel Ships consume and the limited amount of waste plastic available to produce fuel from. For instance, one Commercial European Plant is unable to keep up with demand and is having to import waste plastic from the UK. But the UK has the same issue with three Commercial Plants and are importing waste plastic from China. As more and more of these commercial Plants are built, the more Plastic is needed and even though we think there is a colossal volume of Plastic produced, it is actually not the case when compared to the Volume of Fuel a ship uses.
Just for comparison, the Queen Mary consumes fuel at a rate of 1 US gallon per foot.

[Hoddamdg11]

Copper catalyst?

Another interesting snippet

Renewable energy: Scientists accidentally turn carbon dioxide into ethanol - Science News - ABC News (Australian Broadcasting Corporation)

[cornishscrimper]

Is it possible to convert most of the output into gas rather than liquid fuels ? Say with the correct catalysts etc ? Have read through cannot see a mention of it.Thinking about off grid set up and using gas (not gasoline) to run generators, gas fridges , cooking and gas water boilers etc.