How to turn plastic waste into diesel fuel cheaply

[wheels]

Do you think is it the throughput to holding tank volume ratio that is key here in getting the lighter fraction to evaporate out of the diesel before the diesel is drawn off, or do you think it is the throughput to available surface area for evaporation ratio that is more important? I am thinking of using a 250mm diameter horizontal round pipe (could be 1m long, could be 6m long, just so long as it is kept at the right temperature) - the condenser feeds into one end, the pipe level is kept half full, the condensate flows from one end to the other and out a drain pipe which turns up to a tap at the half full point. The drain pipe could be run back along the length of the 250mm pipe without insulation for cooling before exit. This way achieves a high surface area to volume ratio which I believe is important to efficient vaporisation and identified as the ideal fill point in lab set ups.
Col

I use smaller tanks and they are filled with Stainless Steel swarth from the Lathe. This allows plenty of surface area for the condensates to condense out on, but the tank is kept at temperature. So only the fractions of the required weight will condense out and the rest of the vapor flows on through to the next vessel.

[Col]

Comments assuming you are using standard series condenser setup: 60L tank is small for 1000L batch so given this is the case, diesel will be removed before it has had sufficient time to bleed off the lighter volatiles. Therefore some further processing of the removed diesel will likely be necessary. My tank is 500L.

Do you think is it the throughput to holding tank volume ratio that is key here in getting the lighter fraction to evaporate out of the diesel before the diesel is drawn off, or do you think it is the throughput to available surface area for evaporation ratio that is more important? I am thinking of using a 250mm diameter horizontal round pipe (could be 1m long, could be 6m long, just so long as it is kept at the right temperature) - the condenser feeds into one end, the pipe level is kept half full, the condensate flows from one end to the other and out a drain pipe which turns up to a tap at the half full point. The drain pipe could be run back along the length of the 250mm pipe without insulation for cooling before exit. This way achieves a high surface area to volume ratio which I believe is important to efficient vaporisation and identified as the ideal fill point in lab set ups.
Col

[Col]

hmmm, ok thanks. I don't know for sure if it was boiler plate, the engineers suggested it could be, but they were not particularly expert engineers, did big stuff but couldn't be relied on to know everything... can any of us?
It wasn't dead flat, it had a lot of lumps on it, like slugs crawling over it, and it was corroded. We took at it with angle grinders to remove the worst of the lumps and it took a lot of work, grinding discs and time to get through the few lumps we did grind down. I didn't recognise it as stainless steel when grinding it.
But point taken, stick to the common mild steel. Thanks.

[wheels]

Hey guys.
Years ago at work while digging a trench for a phone line we hit steel plate and pulled it out with the truck. It was a 4.8m x 1.2m x 10mm sheet of boiler plate. We asked the structural engineers next door to drill some 20mm holes around the perimeter so we could use it for a job. Apparently they couldn't penetrate it cold and had to heat it really hot (don't remember what temperature) before their drills would work on it. We still have the sheet and I was thinking boiler plate would be great to use to make the retort on the next system after proving my small pilot plant.
I am doing the welding myself on my small plant but would contract a boiler maker for the next one. Does anyone know what considerations need to made when using boiler plate in this application?
Thanks

Interesting. How did you know it was boiler pate? Normally Boiler plate is just a high quality Wrought Iron, which is fairly soft and actually has reasonably good corrosion resistance when in contact with Boiling water. I wonder if it could have been some kind of Alloy like a Stainless Steel, which can still rust when buried, because contamination from Iron on the soil and lack of oxygen can cause it to rust. So it then looks like ordinary steel plate. But an interesting thing can happen with Alloys with age. It is called Precipitation Hardening. Normally it is done with heat to speed up the process, but some Alloy steels have been known to "improve" when left for many years. Otherwise I really don't know of anything that you would find as a Plate that would be so hard to drill.
Some time in the future, I will be experimenting with different metals, but at the moment, I have come to the conclusion that the cheapest method is to use Mild steel, expect it to corrode eventually and replace it. There are some special SST's that have great resistance to heat and corrosive products, but they are expensive and difficult to work with, so getting a Retort built from such materials can be expensive.

[wheels]

Hi.....i've been following u guys for sometime now, read a good measure of the pages (not all) and I appreciate and respect all your effort.....really u guys are great... thanks....I have some questions that I need your help with..... they might sound stupid but please pardon me

the uncondensable gas that leaves the bubbler finally what is it made off??? is it methane? buthane? or hydrogen?

2) how well does the diesel work when mixed with regular diesel ? say at a ratio of 1:1

As they say, the only stupid question is the one not asked. This Forum is here for Questions and answers and everyone is at different levels in experience. So don't worry about thinking your question may be stupid. Because I am sure the answers will help others as well as yourself.

The Gas output, which is called the "Off Gas", is in fact an interesting question. Mainly it is Hydrogen. But other components are present and what and how much of the what depends on several things.
The Off Gas make up is why the importance of specific Plastics being pyrolized need to be adhered to. PP and PE plastics are the safest as far as the chemicals being released int he Gas. Mainly Hydrogen and a little Methane. However, it does also depend on Retort Temperature and if any catalyst is used and of course, the design of the plant. Design and temperature equates to how much cracking takes place. High temperatures produce a lot more non-condensable gasses. At the extreme end, Propanes, Propenes and can be created. But unlikely in most backyard plants as you need very high temperatures to produce any of them in quantity.
Any other plastic types can produce extremely deadly toxic and corrosive Gasses. The main three are Hydrogen Chloride (Hydrochloric Acid in Gas form), Hydrogen Cyanide and Chlorine Gas. So great care needs to taken that the wrong plastic types do not enter your Feedstock.

[Excalibur]

Hi.....i've been following u guys for sometime now, read a good measure of the pages (not all) and I appreciate and respect all your effort.....really u guys are great... thanks....I have some questions that I need your help with..... they might sound stupid but please pardon me

the uncondensable gas that leaves the bubbler finally what is it made off??? is it methane? buthane? or hydrogen?

2) how well does the diesel work when mixed with regular diesel ? say at a ratio of 1:1

The noncondensable gases are a mixture if I recall. It is highly flammable and a valuable heat source. See member: Wheels posts on the subject of composition, probably within the last 12 months.
There are numerous reports of this diesel being used as fuel on this forum even going back to the 1st pages initiated by Jetijs. Blending with regular diesel is fine and I'd expect a performance improvement because the bought stuff has cetane improvers whereas our DIY stuff is raw. However with our fuel we can optionally target slightly higher specific gravity so it is slightly more energy dense. Preferable for our product would be an additive package containing a cetane enhancer, deposit controller and oxidation stabilizer.
Continue the reading through, it's the easiest best way to learn and as a bonus it's free. If you're like me, you'll need to re-read some parts a few times to get it to sink in. I suggest dedicate 30min a day to reading and call it an investment.

[Col]

types of metal - boiler plate

Hey guys.
Years ago at work while digging a trench for a phone line we hit steel plate and pulled it out with the truck. It was a 4.8m x 1.2m x 10mm sheet of boiler plate. We asked the structural engineers next door to drill some 20mm holes around the perimeter so we could use it for a job. Apparently they couldn't penetrate it cold and had to heat it really hot (don't remember what temperature) before their drills would work on it. We still have the sheet and I was thinking boiler plate would be great to use to make the retort on the next system after proving my small pilot plant.
I am doing the welding myself on my small plant but would contract a boiler maker for the next one. Does anyone know what considerations need to made when using boiler plate in this application?
Thanks

[skymagic]

Hi.....i've been following u guys for sometime now, read a good measure of the pages (not all) and I appreciate and respect all your effort.....really u guys are great... thanks....I have some questions that I need your help with..... they might sound stupid but please pardon me

the uncondensable gas that leaves the bubbler finally what is it made off??? is it methane? buthane? or hydrogen?

2) how well does the diesel work when mixed with regular diesel ? say at a ratio of 1:1

[Col]

Great, thanks guys. I drive a petrol at the moment but have diesels at work so can use the fuel either way. Thank you for your feedback guys! Looking forward to using this free fuel

[wheels]

I think Col is wanting to run the Fuel in a Petrol engined Vehicle, not Diesel.

[Beyond Biodiesel]

Hi guys
I have been given 4 x 200L drums of petrol from an automotive workshop. It is very clear and seems clean. I don't know whether it was drained as straight petrol or a diesel - petrol mix. I also scored a 60L drum of diesel from the same place so I am assuming the drums of petrol are mostly just petrol as they have at least made an attempt to keep the two fuels separate. It is obviously an accumulation of fuel from many jobs so I think it will need to be separated / distilled before use.
I was hoping to just distil the petrol between 30C - 210C and use it in my car. Does anyone know whether that will have an adverse effect on hydrogen or additives that may have been added after the distilling process at the refinery? Would I be turning the petrol back into the naptha product that we wouldn't want to put in our cars?
Thanks in advance
Col

I agree with Excalibur, good score; and check the specific gravity of the contents of the drums. If they match either gasoline or diesel fuel, then all you need do is filter them down to about 1-micron, and run them in the respective engines, and forget about distillation.

Even if the sg of the gasoline containing drums is to heavy for running on a gasoline engine, and you have a diesel engine, then just blend it with some relatively clean waste oil to .850sg, settle it for about 2 weeks, then filter it down to about 1-micron, and run it until it is gone.

[Excalibur]

Good score on the free drums of fuel!! There's a number of things to consider but the first thing I'd do is measure the SG. Possibly the drums will contain 'miss-fuel'. This is the fuel drained from vehicles that have had the wrong product pumped in to their tanks.
Without knowing what the SG is, I believe you have good base stock for making homebrew diesel. The SG will have to be tweaked to .82 - .85 SG.

[wheels]

Hi guys
I have been given 4 x 200L drums of petrol from an automotive workshop. It is very clear and seems clean. I don't know whether it was drained as straight petrol or a diesel - petrol mix. I also scored a 60L drum of diesel from the same place so I am assuming the drums of petrol are mostly just petrol as they have at least made an attempt to keep the two fuels separate. It is obviously an accumulation of fuel from many jobs so I think it will need to be separated / distilled before use.
I was hoping to just distil the petrol between 30C - 210C and use it in my car. Does anyone know whether that will have an adverse effect on hydrogen or additives that may have been added after the distilling process at the refinery? Would I be turning the petrol back into the naptha product that we wouldn't want to put in our cars?
Thanks in advance
Col

Do you have a Diesel Vehicle at all? I would add the liquid you think is Petrol into Diesel, but at no more than 10%. A Diesel engine can cope with that just fine.
The big issue with distilling the Petrol is that you may still have oil in the finished product and while the Petrol engine may run OK, you may have a smoking issue with the exhaust output. It takes just a little Diesel added to a Petrol engine fuel tank to make the Engine produce Blue smoke terribly.
You could try distilling with a lower High point Temperature. Like maybe 160Deg instead of 210Deg and then add the lighter product to bought Petrol to ensure you have all the additives. But then you will end up with a heavier weight product to try and dispose of. Maybe sell it or give it away to a friend with a Diesel Vehicle or add it to heating fuel or something.

[Col]

distilling petrol

Hi guys
I have been given 4 x 200L drums of petrol from an automotive workshop. It is very clear and seems clean. I don't know whether it was drained as straight petrol or a diesel - petrol mix. I also scored a 60L drum of diesel from the same place so I am assuming the drums of petrol are mostly just petrol as they have at least made an attempt to keep the two fuels separate. It is obviously an accumulation of fuel from many jobs so I think it will need to be separated / distilled before use.
I was hoping to just distil the petrol between 30C - 210C and use it in my car. Does anyone know whether that will have an adverse effect on hydrogen or additives that may have been added after the distilling process at the refinery? Would I be turning the petrol back into the naptha product that we wouldn't want to put in our cars?
Thanks in advance
Col

[chacowako]

a good read for people just reading this thread

http://ir.canterbury.ac.nz/bitstream/10092/4303/1/Thesis_fulltext.pdf