How to turn plastic waste into diesel fuel cheaply

[dedooo]

Hello all, I want to ask this Can I put food oils used in the pyrolysis retort? And What do I get? Thank you

[Excalibur]

Do you think Jet's mention of "refluctor" actually reasons as our "reflux zone"?
.

Yes

My reflux is 300mm diameter at the base and sits directly on top of my retort, their is no "v" cone shape on the base as he mentioned!
.

Don't worry about the v shape. As long as any condensed hydrocarbons are able to run back freely to the retort, all will be well.

You mentioned that your reflux is measured approx 380*c with WMO.for good results.I would have thought that melted plastic reverts back to hydrocarbons similar to waste motor oil,not exactly same,but still hydrocarbons.Therefore your higher temp value at reflux interests me..

Note, I mention 350°C as my reflux target. At the 380°C, there would be almost no refluxing going on, in other words you'd be getting out product at much the same weight you were putting in. The temperature is really a balance of a number of variables so each operator needs to be ready to adjust it to suit their particular conditions. Perhaps the most important criteria deciding the reflux target is the weight of product being produced.
Product produced too heavy: remedy = lower the reflux temperature.
Product produced too light: remedy = raise the reflux temperature.

My next run tomorrow will be a mixture of LDP AND USED MOTOR OIL.This way also allows me to get more product in my retort.

Good idea. Fill to about 3/4 maximum for safety.

Great info on K-type thermocouple, i currently use the same,not sure if grounded or not.Those PID control items are so cheap on that site compared to South Africa.i.e four times cheaper.
THKS.

The k-type is industrial quality 1.5m long so it can reach near the bottom of the retort. The cheaper k-type with fiberglass insulation would not last as the insulation deteriorates.
The PID controller is not the cheapest either. Others are there if you want to take the risk. I look carefully at a sellers rating and also what Google can tell me about the product, in this case the Sestos brand had good reports.

[rozier56]

Do you think Jet's mention of "refluctor" actually reasons as our "reflux zone"?
My reflux is 300mm diameter at the base and sits directly on top of my retort, their is no "v" cone shape on the base as he mentioned!
You mentioned that your reflux is measured approx 380*c with WMO.for good results.I would have thought that melted plastic reverts back to hydrocarbons similar to waste motor oil,not exactly same,but still hydrocarbons.Therefore your higher temp value at reflux interests me.My next run tomorrow will be a mixture of LDP AND USED MOTOR OIL.This way also allows me to get more product in my retort.
Great info on K-type thermocouple, i currently use the same,not sure if grounded or not.Those PID control items are so cheap on that site compared to South Africa.i.e four times cheaper.
THKS.

[Excalibur]

Excalibur, thks for your response, i had a lesson on control of my duel burner and found out it was set at max output{65Kw/hr}. far too hot,reset to 40Kw great temp control.Great info on your blog site,have a few questions.
What is the volume of your retort?
At what reflux temp do you get best diesel production?
Are you happy with the ungrounded K-type thermocouple?
If one produces waxing material is this too high temp or too low temp?
Most info shows best diesel production at 280*c? in the distillation column.
My raw material is ldp plastic.Thanks.
Anybody can please respond to these queries.

Retort is 47 liters.
Reflux temperature target is 350°C on wmo feedstock. This gives a specific gravity of .84 ~ .85 SG. I haven't tried plastics in this retort yet but the reflux figure would be reduced if waxing occurs.
Ungrounded thermocouples are essential for some types of electronic equipment. Feedback voltage spikes on the earth/ground cause problems for sensitive readings and thermocouple readings are already incredibly minute that ANY stray voltage will upset them. My large red LCD's and the Arduino thermocouple breakout board both require non-grounded. The cheap Chinese handheld meters are Ok with grounded presumably because their battery is not itself grounded. K-type is the way to go for us DIY diesel makers. Be sure to check the maximum degrees a k-type TC can read. I think the rule is that thinner TC wires can only read up to a certain temperature figure.
Typically, fuel waxing will be too high temperature in the reflux. This assumes that the retort is not in any kind of boil-over mode with it's temperature carefully controlled somewhere in the region of 380°C ~ 425°C.
When Jetijs had waxing problems he solved it by cooling the reflux to 150°C
See post 680
I recommended k type TC for retort, reflux and burner, otherwise you are working blind.
I just today ordered a new mineral insulated k-type TC and a PID controller

[rozier56]

Excalibur, thks for your response, i had a lesson on control of my duel burner and found out it was set at max output{65Kw/hr}. far too hot,reset to 40Kw great temp control.Great info on your blog site,have a few questions.
What is the volume of your retort?
At what reflux temp do you get best diesel production?
Are you happy with the ungrounded K-type thermocouple?
If one produces waxing material is this too high temp or too low temp?
Most info shows best diesel production at 280*c? in the distillation column.
My raw material is ldp plastic.Thanks.
Anybody can please respond to these queries.

[Beyond Biodiesel]

my system details

Impressive machine kedigen. I hope it works out well for you. It looks like you will be heating it with liquid or gaseous fuels?

[Excalibur]

I suggest a thermocouple probe for the retort that extends into the liquid. The signal from this can be made to start and stop the burner and maintain the correct temperature range. I'm about to fit a new mineral insualted thermocouple for my retort with controller for my burner shortly and will be updating this info soon.

For the burner, a smaller nozzle to put the heat output into a better range may be required. See this Delavan nozzle PDF for some good information.

[rozier56]

Hi Excal,Thanks for your input,i have attached a picture for your info and will expand further if it works.Ok, got some pics to work.
Plant retort is 240kg.
Reflux is 42lt capacity.This is were i measured 200*c when the problem started.
Condenser internal pipeware 1inch.
Temp measurement is on top of the reflux column and on the diesel chamber.
Retort has 10cm vermiculite insulation
Reflux has 8cm vermiculite insulation.
Low density plastic used as raw material, i.e irrigation pipe.
I am going to learn how to reduce the burner output to get a better temp control.

[Excalibur]

Hi folks,New problem for me, but i believe others have had this happen in past.
Brand new system built same as before but this time my heating source was a new duel fired diesel heater.Old system was on lpg gas, but bought new system to improve production time etc.The diesel heater has a capacity of producing 69Kw/hr..
When i fired up the system i reached 200*C IN 15min, all looked good, then started producing wax product that carried over to my collection tank.Stopped plant.
In the past with lpg this never happened.I think this is because i had a too fast increase in temp and caused blow through?
Only other change i made was to the distillation column, where i went from the plate system of baffel's which gave me a wet -out in certain temp range to a composite of fillings of metal internal.i.e simple distillation.
Would appreciate your feed back.

rozier56, there is not enough information and no pictures but some thoughts as a preliminary diagnosis..
The wax is uncracked plastic so some possible causes are.
Boil-over. Perhaps too much volume of heat pushes the product through all to quickly and forcefully.
Reflux problem. Perhaps the increase in heat is causing the reflux to overheat. Too hot reflux temperature will cause product to escape without any cracking.

Where in the reactor is the temperature probe? Top, side, bottom, etc?
What temperature did the reflux reach?
Is there a temperature probe monitoring the burner flame?

Please inspect your pipework, condensers etc for wax & plastic blockage before attempting to re-run.

It occurred to me after my last run that the temperatures, setting, size of parts etc are all working in a kind of harmony so changing components can have unexpected effects. In my case, I'd added insulation to the retort and I found I had to use less heat.

kedigen. Nice work. Am really wishing you well and good success.

[rozier56]

wax problem

Hi folks,New problem for me, but i believe others have had this happen in past.
Brand new system built same as before but this time my heating source was a new duel fired diesel heater.Old system was on lpg gas, but bought new system to improve production time etc.The diesel heater has a capacity of producing 69Kw/hr..
When i fired up the system i reached 200*C IN 15min, all looked good, then started producing wax product that carried over to my collection tank.Stopped plant.
In the past with lpg this never happened.I think this is because i had a too fast increase in temp and caused blow through?
Only other change i made was to the distillation column, where i went from the plate system of baffel's which gave me a wet -out in certain temp range to a composite of fillings of metal internal.i.e simple distillation.
Would appreciate your feed back.

[piu.iuu]

Hi Andrew, yes, we modified the condensers putting three together in hope to searate diesel from gasoline, but the condensers were not heated and it did not work. Might be that only insulating the first condenser will do the trick, but it would not be reliabe as the temperatures need to be kept constant.

Jetijs

I was thinking, try using High Temperature Heating Cords you can get them at BriskHeat HWC High Temperature Heating Cord: High Temperatures and Extreme flexibility. Easy use on small tubes, vessels, or any place where space is limited. It might do the trick.

Hope it helps

[fox32]

Fox32, if you're thinking of a sight glass then this page lists critical temperatures for pyrex borosilicate. Better would appear to be fused quartz with continuous operating temperature of 1000°C.

Listed here is a possible gasket material fiberfrax quoted range (+704°C – +1260°C)

Ebay fused quartz listing is the cheapest I have found. 105mm x 8mm disk.
I've been eyeing these for a while trying to decide if I could add one to the side of the reflux. I'm busting to be able to see in there

Should a sight window be fitted anywhere, a safety shutter could be added outboard of it so in case of emergency it could be hastily closed. Just a thought.

Whether they'd stay clean enough to see is another question entirely.

Those lens look really good, it would be a nice addition to the pyrolisis unit. Actually i was thinking at a sight glass, let-s say your sight glass, put it on top of the retort and put this http://www.sculesiechipamente.ro/med...melon_1002.jpg in it atached to a crank, so one could raise and lower it into the retort thus seeing the oil level. But i found something tested and trialed here A Dozen Ways to Measure Fluid Level and How They Work | Sensors The displacer one looks the most promising to me, it looks like it could be done in a diy environment.What do you guys think?

Also on the relative cheap side, i'we found this -> DIAL GAUGE LEVEL METER - TOWA SEIDEN INDUSTRIAL CO.,LTD.


P.s. Sorry if my english gives you head aches, it sounds way better in my native language.

[mercedes 308]

so can l use another material like cement to binder and holds the particles together..ash+glass+cement or other material?

60% sand and 40% plaster of paris. will take high temperatures, more than you will need.

[Excalibur]

Fox32, if you're thinking of a sight glass then this page lists critical temperatures for pyrex borosilicate. Better would appear to be fused quartz with continuous operating temperature of 1000°C.

Listed here is a possible gasket material fiberfrax quoted range (+704°C – +1260°C)

Ebay fused quartz listing is the cheapest I have found. 105mm x 8mm disk.
I've been eyeing these for a while trying to decide if I could add one to the side of the reflux. I'm busting to be able to see in there

Should a sight window be fitted anywhere, a safety shutter could be added outboard of it so in case of emergency it could be hastily closed. Just a thought.

Whether they'd stay clean enough to see is another question entirely.

[fox32]

Actually if we put a pyerx glass, it would look like the professional one. Unfortunatley the clossest i can afford to pyrex glass is an oven door from scrapheap, so i got to find something simpler, and preferably something that wouldn't need major modifications to the retort. A very simnple idea come to mind today, while cutting and measuring some wood planks.

How about a steel ruler, put on top of the retort in a glass continer sealed tight and actioned by a hand crank. The ruller goes into the retort through a small opening and you wind it until you can see oil on it.(like a car oil probe) It is already marked with cm, basically the whole mecanism exist in the ruller, we just need to atach it to a crank and build a glass box around it. The problems i see would be the glass box geting foggy from the vapors, and the worst will be, if the vapors make the whole ruller wet and spoil the reading.

On another page, isn't it there a device that could read if there is water in a pipe? I think i saw something like that long time ago at a plumber.