How to turn plastic waste into diesel fuel cheaply

[Beyond Biodiesel]

Thanks, kedigen for the useful links. My response seems to have been deleted by the moderator.

Earlier on I had to dump heat in whatever way I could. Typically I found myself in a position of having to bleed away the heat part way through a run. So it was a case of starting out, not knowing what to expect, then having to adapt on the fly. Now I'm recovering the heat by exchanging it onto the incoming feedstock. This is one of the steps I use to economize and reduce heat waste.

Recylcing heat this way sounds useful. I found early on that HCL was a distinct possibility in distilling WMO due to the presence of TCE contamination use a common auto shop solvent, so my solution for it was using my cooling water as the feed for the bubbler to keep it from getting saturated with HCL.

There's lots to like about fractionating columns. Step by step with the basics first One of the best Youtube fractionating column

I remember that video. I found it very instructive on fractionation.

Taking the unit on site to not only where the raw material is but also where the finished product is required is a great idea.
Brainstorming recently talk arose about the possibility of (20')containerizing my Orion retort refinery for shipping. The 20' container could be shipped anywhere there was a need or perhaps every remote village could build one.
Obviously it will need more work before it can lose its' prototype status.
Lucky that dreams are free

Yes, making the unit portable so that it can be taken to the source point, or point of use is a good idea, that has been my goal all along. Putting it in a 20' container, if your unit is that big, is a good idea. Mine looks like it is going to be a 4 foot cube, so putting it on a pallet makes it fit the shipping stream much better, and it will have the same capacity as yours when I am done.

[Excalibur]

There are advantages to the column, primarily in reducing foot print, and heat losses, and as Excalibur pointed out, he had more trouble dumping excess heat from his vapor stream, than containing it.
.

Earlier on I had to dump heat in whatever way I could. Typically I found myself in a position of having to bleed away the heat part way through a run. So it was a case of starting out, not knowing what to expect, then having to adapt on the fly. Now I'm recovering the heat by exchanging it onto the incoming feedstock. This is one of the steps I use to economize and reduce heat waste.

The significant advantage that a horizontal fractionation system has for the DIY is it is very easy to implement and does not require a 40 foot tower, which is a very expensive thing to build in one's backyard, and dangerous to clamber about on for service.
.

There's lots to like about fractionating columns. Step by step with the basics first One of the best Youtube fractionating column

The next iteration of my pyrolysis unit will be to do both up and out. I plan to fold my horizontal design in half so that, instead of being 2 feet (.6m) wide, 2 feet (.6m) tall and 16 feet (9m) long it will be 2 feet (.6m) wide, 4 feet tall (1.2m) and 8 feet (4.5M) long. Later I might fold it again to make it a 4 foot (1.2m) cube. At that point it will fit on a standard 4 foot (1.2m) pallet and could be shipped anywhere.

Taking the unit on site to not only where the raw material is but also where the finished product is required is a great idea.
Brainstorming recently talk arose about the possibility of (20')containerizing my Orion retort refinery for shipping. The 20' container could be shipped anywhere there was a need or perhaps every remote village could build one.
Obviously it will need more work before it can lose its' prototype status.
Lucky that dreams are free

[Beyond Biodiesel]

Last Question, has anybody made a Fractionating column? how would they work,any advantage over the seperate condensors? I'v seen them discussed in the forum but does anybody have a diagram/design of one?

Thankyou

I built several distillation columns of various sizes out of glass ware up to 2 stories tall doing post graduate research at Chevron. There are advantages to the column, primarily in reducing foot print, and heat losses, and as Excalibur pointed out, he had more trouble dumping excess heat from his vapor stream, than containing it.

The significant advantage that a horizontal fractionation system has for the DIY is it is very easy to implement and does not require a 40 foot tower, which is a very expensive thing to build in one's backyard, and dangerous to clamber about on for service.

However, if you are going commercial, then real estate is expensive as well, so a tower might be a good trade off.

The next iteration of my pyrolysis unit will be to do both up and out. I plan to fold my horizontal design in half so that, instead of being 2 feet (.6m) wide, 2 feet (.6m) tall and 16 feet (9m) long it will be 2 feet (.6m) wide, 4 feet tall (1.2m) and 8 feet (4.5M) long. Later I might fold it again to make it a 4 foot (1.2m) cube. At that point it will fit on a standard 4 foot (1.2m) pallet and could be shipped anywhere.

[Excalibur]

I'v modified my Condensors with Steel wool inserted inside. To see if it helps Condensation. Will check on yield this week.

I have a question regarding burners. I have been using a simple round Gas burner aided with a weak blower.

Would a Venturi type burner give a better flame and heat? As i have been struggling to get the Retort heat above 380 C .

Last Question, has anybody made a Fractionating column? how would they work,any advantage over the seperate condensors? I'v seen them discussed in the forum but does anybody have a diagram/design of one?

The issue with condensers that I had earlier on was I struggled to keep the temperature low enough. With all the heat carried by the vapor stream, there wasn't enough heat exchanging going on to keep it cool.

About the burner. I believe I'm right in saying that even a simple gas ring has a venturi
Also a regular lpg gas torch uses the principle. Have you seen a burner that looks promising?

Would increasing gas pressure or orifice size help? Here's a good BTU chart to orifice size

BTW. is there a flue stack installed for the burner?

[dippy909]

I'v modified my Condensors with Steel wool inserted inside. To see if it helps Condensation. Will check on yield this week.

I have a question regarding burners. I have been using a simple round Gas burner aided with a weak blower.

Would a Venturi type burner give a better flame and heat? As i have been struggling to get the Retort heat above 380 C .

Last Question, has anybody made a Fractionating column? how would they work,any advantage over the seperate condensors? I'v seen them discussed in the forum but does anybody have a diagram/design of one?

Thankyou

[Beyond Biodiesel]

Excalibur
Also Beyond Biodiesal mentioned using iron wool, would it also be a good idea to put Wool into the Condensor to hep the vapour condense?

My condenser traps are filled with steel wool to give surface are for the vapors to precipitate out on. However, my condenser traps are not much larger than the maximum volume possible that could condense there. I start with a 5 gallon (20L) retort for distilling WMO, so each of my condensers is 5 gallon (20L).

The retort is also full of course steal wool. The steel wool there acts as boiling chips to equalize the temperature in the boiler, as well as refluxing material.

[rozier56]

Thk's Excalibur, i will monitor the reflux better.yes it seems that the wax seems to have a tendency to "seed" the product,same as sugar does,which is my chemical background.

[Excalibur]

Thks Beyond,If i increase heat/temp to 480/500*c then i am getting a parrafin wax on cooling.Want to avoid this happening.I do have a pressure gauge on the system and never get higher than half a bar.I will definitley be putting a further cooling condenser in line and also doing away with right angle connections in the gaseous stage. My main reason for improving flow is because a few local farmers want to buy the unit and they need a higher production rate to meet their demands.

At those temperatures, you'll likely be experiencing boil-over so some uncracked fuel will be exiting downstream. Earlier on, Imakebiodiesel discovered that relatively small amounts of semi-cracked plastic ruined a large amount of diesel by making the lot turn to wax.

I recommend monitoring the reflux temps and adjust to suit your exact conditions.

[Excalibur]

Excalibur
Im going to Insulate the first Condensor and see if i can get a Thermocouple on it to check the Temperature.
Also making my Condensor from Air cooled to Water cooled.
Regarding Condensors, would be advantageous to have a larger Diameter Condensor to give the Vapours more time/surface area to condense. At the moment im using just a 4 inch pipe.
planning to install sight glasses soon.

Thankyou
Also Beyond Biodiesal mentioned using iron wool, would it also be a good idea to put Wool into the Condensor to hep the vapour condense?

I made a mistake with mooting the possibility of limestone in the bubbler water. We were talking about getting the smell out of the fuel so it can't be done via the bubbler. Sorry, a bit of brain-fade on my part trying to post late at night!
No, the fuel would need to be processed after it was removed from the condenser. Perhaps a small quantity of fuel could simply be soaked in limestone or larger amounts could be slowly pumped through a vessel containing the limestone. The man with that Shell petroleum book is due to visit when I run my retort next so I'm planning to ask for another look.

The condenser ideas might just work. Keep trying things till you find something that works. Initially it's more about proving the concept, later more important is liters per hour.
Yes a temperature sensor for the diesel vessel is an excellent investment. I bought some cheap 12v probes with LCD to 150*C for about US$7 with LCD.
Temperature Meter 50℃～150℃ Blue LCD with Probe | eBay
I'm aiming for 80*C so well within their scope.

Yep, you'll love the sight glasses. Not only can you see the flow, but any boil-over can be seen as well.

The steel wool idea in condensers should effectively increase the surface area so I think it will work in your favor.

Vermiculite and perlite would be one of the better "fill" insulators. It's maybe a bit pricy but it doesn't burn and good to 1200*C (from memory) so maybe consider it a safety feature.

[dippy909]

Excalibur
Im going to Insulate the first Condensor and see if i can get a Thermocouple on it to check the Temperature.
Also making my Condensor from Air cooled to Water cooled.
Regarding Condensors, would be advantageous to have a larger Diameter Condensor to give the Vapours more time/surface area to condense. At the moment im using just a 4 inch pipe.
planning to install sight glasses soon.

Thankyou
Also Beyond Biodiesal mentioned using iron wool, would it also be a good idea to put Wool into the Condensor to hep the vapour condense?

[Beyond Biodiesel]

Thks Beyond,If i increase heat/temp to 480/500*c then i am getting a parrafin wax on cooling.Want to avoid this happening.

No need for the higher temperatures. They are probably just causing boil-over.

1]The Gasket is a Spiral wound type, not sure of the type, rated to 450 C, changing to a metal type Gasket this week as the gasket needs constant changing.

3]Thanks for this information and yes it started melting today so am changing insulation immediatly, Charcoal sound s interesting but how could it be packed ?

Charcoal, or any solid granular insulation would need to be put inside of a metal housing. So, for instance, in the case of your reflux column, if you are handy with sheet metal fabrication, or you can hire someone who is, then you could build a clam-shell enclosure for your reflux with a hinge on it, so that it is easily removed for service.

There would have to be a void between 2 layers of sheet metal, an outer layer and an inner layer. The inner layer of sheet metal would be close to your hot object, such as your reflux. The outer layer would be outside, and in between would be a 4" (10cm) void that is filled with charcoal.

You could use your retort to make the charcoal that you need, and extract the volatiles from baking wood into charcoal in the same way you extract, or crack, plastic into diesel fuel. You would use the wood volatiles as fuel in the same way you would use the distillate from your plastic cracking.

4] On your reflux I think it is too far above your retort, and you do not need the narrow pipe. Since you are using standard flanges, then whatever the maximum ID of your flange should be the ID of the reflux, and it would be immediately above your retort, with no pipe in between.

A good question. I had a loan of the book that talked about the limestone but I gave it back. I wonder if coarse limestone in the bubbler water would work? Untested theory caution.

Any limestone (calcium carbonate) will work to neutralize acids, but metals, like steel, aluminum, or copper, will work as well.

[Excalibur]

Excalibur

Thankyou for your response.
1. Does your fuel ignite with a match? (Test carefully please!)

Yes its Ignited quite well

Then it has a volatile content probably just a few percent. By holding the fuel at 80*C or so, the volatiles will evaporate. The real answer is to hold the diesel condenser vessel at the 80* mark while you are making fuel and drive the volatiles downstream to a water quenched condenser. Then those volatiles can be used for another purpose and not lost.

2.Did it turn to wax once it cooled?

No it was left out last 3 nights (8 C) no waxing

Good, the fuel that was plastic has completely cracked. Where it doesn't crack enough it will convert to wax.

3.It sounds like there was too much refluxing or the retort temps were too low.

Agree Reflux was just too Cold, Now been insulated.

4. Temperature probes on the retort and reflux are very helpful. You need to know what's going on there!

Installed on both.

Excellent, the gauges are important. Another good item would be a borosilicate sight glass. It's another tool to aid in the understanding of exactly what is going on inside a retort where you can't see. Fit this where fuel drops into a condenser as a drip rate indicator.

8. The strong smell of cracked fuel is commonly reported
How could we run the Fuel across Limestone, can we use Calcium Hydroxide?
Also how ?

A good question. I had a loan of the book that talked about the limestone but I gave it back. I wonder if coarse limestone in the bubbler water would work? Untested theory caution.

The unit was modified with a Condensor straight after the Reflux (The idea was to capture more Diesal, Pictures attached) , Thermocouples on the Retort and reflux a Fan blowing Air for the burner. A second bubbler containing Calcium Hydroxide and water (now this I think is wrong please correct me what the second bubbler should contain to reduce toxins in the gas )
I had obtained Zeolite powder but forgot to add it to the feedstock.
(Trying to source the Pellets version so I could put it in the reflux.)

Upon operation thet LAsted 3 1/2 hours
3.5 kg mixed plastic feed , containing 2 PEt bottles.
The oven Peaked at 384 C, The reflux heated very slowly, but acclerated after hitting 100C the maxed at 254 C, was it too much?
A good reaction happened when it hit around 350 C, Liquid flowing in the pipeworks and Condensor, sounds like a stream, but short-lived did not last that long.
When the process stopped no bubbling or activity in the pipeworks it was stopped.
The Gas output was very poor compared to my first run. on/Off no much pressure.
The Retort had 1 inch of solidified wax, Two questions, is this teh result of not reaching a higher cracking temperature, and secondly can I re process this?(Pictures attached).
The Fuel out put seems dissapoiting I was expecting 3.5 liters from 3.5 kg of feestock. Secondly the First condensor gave gold Fuel , SG of 7.75 around 1 liter. But it is not Clear its cloudy, how can I get it clearer
The Second condensor which had air cooled pipes gave dirty Fuel this time and it contained water? Why do you think it is dirty? when inmy last run I had fairly clear fuel from this condensor?
COuld you clarify why water has formed in the process I read in the thread that it can be due to PET but i had only two water bottles.
Both fuels burnt well.

What can I do to tune it for Diesal? , Should I add a third condensor.
Apologies if it is a bit long reply
Thank you

Take care the diesel reservoir vessel doesn't overheat, I think 80*C but depending on how hard you choose to drive the volatile content out.

Zeolite is available as BBQ fat absorber and kitty litter. (I haven't used it though)

Retort and reflux are on the low side. Both require tweaking. A retort too low will not get enough cracking while too high will risk boil-over and possibly encourage wax. A reflux vessel that's too low will reflux too much while too high will allow uncracked fuel to escape downstream and make too heavy fuel or become wax.

You would only require a third condenser if you needed to separate a third fuel type.

I suspect the water was in some of the plastic feedstock bottles. If you set the diesel vessel to 80* or even 60*c the water will not live there and will evaporate off downstream. On a water cooled petrol condenser, any water will not evaporate and will need to be manually separated.

[dippy909]

Beyond Biodiesal

It looks like you have a proper flange, which is good. But, what are you using for a seal on your flange?


The Gasket is a Spiral wound type, not sure of the type, rated to 450 C, changing to a metal type Gasket this week as the gasket needs constant changing.


2) You condenser line seems to be horizontal. It should lean down toward your condensate trap.

Modifying this week

3) The "glass wool" that you are using looks like ordinary "fiber glass" insulation, which is not glass, it is spun plastic and will melt at the temperatures that you will need for cracking. If you cannot find high temperature insulation in your area, such as Kaowool, then you can use charcoal. Charcoal happens to be an excellent insulation, you just have to keep it from getting above 425c, and keep flames away from it.

Thanks for this information and yes it started melting today so am changing insulation immediatly, Charcoal sound s interesting but how could it be packed ?


Rozier56 is it possible to see pictures of your unit as it seems a good High capacity unit and I have not found reference of pictures in the thread .
Thank you

[rozier56]

Thks Beyond,If i increase heat/temp to 480/500*c then i am getting a parrafin wax on cooling.Want to avoid this happening.I do have a pressure gauge on the system and never get higher than half a bar.I will definitley be putting a further cooling condenser in line and also doing away with right angle connections in the gaseous stage. My main reason for improving flow is because a few local farmers want to buy the unit and they need a higher production rate to meet their demands.

[Beyond Biodiesel]

Hi guy's,I am having some problems with production rate!
I have a 220kg retort with a 4inch diameter reflux column on top.This reduces to 1inch pipe ,then entering the condenser.No problem holding temp{400-420*c} and easily maintaining production rate at 18lt/hr.

Excellent

Need to increase to approx 3olt/hr.My thought's are to increase diameter of the reflux column and increase cooling capacity.
What do you think?:

When cracking and distilling hydrocarbons it is always best not to be in a hurry. On the other hand it is useful to keep developing your pyrolysis unit until you get what you want.

You could try to increase the diameter of your condenser line to increase flow-rate of vapors, but do you have a pressure gauge on top of your retort, so that you know what the pressure is in there? If you do, and the pressure is not increasing more than a few PSI, then increasing your condenser line diameter will not improve your through put. It would mean you need more heat.

Similarly, increasing the cooling capacity of your condensers will only reduce your losses. So, if you know you have not to little losses, then increasing the flow rate of cooling water to your condensers will not improve your throughput. You could add a second condenser to see if you get any more condensate.