How to turn plastic waste into diesel fuel cheaply

[Beyond Biodiesel]

Is the jury back on the cyclone concept? Is anyone actually using a cyclone currently?

I do not recall the topic coming up, but Chevron Research used cyclone separators a great deal for separating the catalyst from the flue-stream. It was very efficient, and could operate at 1200F (600c).

I have also used cyclone separators for separating animal fat and water from my WVO stream when pumping out a storage tank. While it is not super efficient, it definitely works, and it works at high velocity, so that when I pumped from a storage tank, my transfer pump pumped the WVO through a cyclone separator on its way to my mobile storage tank. It worked great.

...When pyrolysing plastic the feedstock is liquid and little or no ash or dust is produced. I have never needed to clean out the top of my retort or pipework after more than 70 batches of plastic.
I dont know if this is the same for WMO as I have only done a couple of small batches but Im sure BB or someone else can comment on that...

Good to know that you are not finding much coke in your plastic pyrolysis unit.

I am still developing my WMO distillation system, so it is not at all a regular process that I run at this time; however, I have run 10 to 20 batches and have not seen the need to clean out anything yet. There is a buildup of coke on the inside walls of my retort, which I expect to have to scrape off one of these days. The pipe work has a thin coat on it, but it has not posed a threat to plugging yet.

[mjohnson1]

How big the shredder pieces come out with this type of shredder. We had those in much bigger scale in the incinerator at cruise ships I used to work on, however it didn't cut the waste to small pieces but just sort of smash and compressing it, making it less bulky.

Do you this one will be suitable for cutting flexible plastic into small pieces that could be further used for continuous feeding?

For HDPE and PP they come out in 1cmX5mm size. Pretty small. Yes it would work great for continious feeding. For plastic bags it doesn't work as well and requires shredding a 2nd time. I mainly shred HDPE buckets i get for free now.

[lowriderzzz]

For HDPE and PP they come out in 1cmX5mm size. Pretty small. Yes it would work great for continious feeding. For plastic bags it doesn't work as well and requires shredding a 2nd time. I mainly shred HDPE buckets i get for free now.

nice - thanks

[lowriderzzz]

temperature - will it be enought

Quick question.Do you think it will be enough to reach 450C with a gas burner like this for my experimental retort from old fire extinguisher.

I'm thinking of putting around it some 1440W heating coils too. I dont know if it will be enought to make 450C temperature with them.

Which method you suppose will be better ? Or perhaps a combination of both ?

What do you suggest ?

[mjohnson1]

lowriderzzz

I have use a propane stove that's almost identical to the picture you provided. It had no problem getting the retort up to 450C with proper insulation.

I got real tired of babysitting the propane burner and having to monitor it all the time in case the wind blew it out.

I switched to an electric kiln to heat my retort mainly because I can control the temperature with a PID controller. I set the retort in the kiln and hook the thermocouple that's welded to the retort into the PID controller and wait until it gets up to temperature. I only use electric for my small scale tests currently.

[lowriderzzz]

lowriderzzz



I switched to an electric kiln to heat my retort mainly because I can control the temperature with a PID controller. I set the retort in the kiln and hook the thermocouple that's welded to the retort into the PID controller and wait until it gets up to temperature. I only use electric for my small scale tests currently.

well but you said your test unit is for 100 grams of fuel - that is less than mine ( 8 litters volume retort ). Do you think electric heating only will provide with enough heat for such a size ?

[Beyond Biodiesel]

well but you said your test unit is for 100 grams of fuel - that is less than mine ( 8 litters volume retort ). Do you think electric heating only will provide with enough heat for such a size ?

I have a 23L retort that I boil 19L of WMO in and I use a coil from an electric stove for a hot plate, 2 band heaters for the sides and 1 line wrap heater for the top and refluxing zone. All of the heaters are designed for well above 425c. It takes about 1500 watts to complete distilling of 19L of WMO in a 4 hour run. I use PID controllers and variacs to control all of the heaters.

[lowriderzzz]

I have a 23L retort that I boil 19L of WMO in and I use a coil from an electric stove for a hot plate, 2 band heaters for the sides and 1 line wrap heater for the top and refluxing zone. All of the heaters are designed for well above 425c. It takes about 1500 watts to complete distilling of 19L of WMO in a 4 hour run. I use PID controllers and variacs to control all of the heaters.

Ok, I assume that as a YES to my question.

Thank you

[Col]

Blending diesel without cracking anything

Yes, it will lower the flash point but that's not always going to present too much of a problem. What's more likely to be an issue is the restarting of the engine once it's shutdown hot and left for 5minutes+. It appears heat-soak can create bubbles in the IP and injectors.
There's a number of if's and but's, but much would depend on the boiling point of the gasoline, climate, vehicle design etc. Recently I tested my local gasoline boiling point and found it was 40'c while the US gasoline is 80'c. This is one reason why experiences can vary.

BBD - "All you need to do is get the viscosity / specific gravity close to that of diesel fuel and you will be able to run your fuel blend on any diesel engine." (don't know how to paste two quotes into one post)

Hi guys. Can anyone with experience in blending diesel fuel help me out on this one?

I have access to a few hundred litres of dirty, oily kerosene per week for little effort. It is used as degreaser for parts cleaning so there will be some contaminants (watch out for TCE right BBD!) but typically grease, oil, road grime etc. I got a copy of the MSDS for the new product which states the boiling range is 150C-280C with a flash point > 61.5C and a kinematic viscosity < 7cSt @ 40C.

It would appear that if I clean it up and blend oil into it to get the viscosity right I can use it in my work trucks.

Excalibur - given the flash point is fairly high I shouldn't have the issues you mentioned above right? Our temperatures here average 10-30C with some colder and hotter days. I have a couple of 10 year old Isuzu 2 tonners, a new Isuzu 5 tonner and one 10 year old Isuzu 10 tonner.

BBD - Should I stick to a standard lube oil for the blending? I figured if I had access to heavy gear oil or even grease I could add less of it to the kero to match the viscosity. But I wonder if the kero and grease will stay blended or 'fall out' like bitumen does? Would long, 'fluffy' grease molecules be ok going through the engines? Some greases have soap (?) or other additives in them, would that be a concern?

Thanks heaps.
Col.

[Excalibur]

BBD - "All you need to do is get the viscosity / specific gravity close to that of diesel fuel and you will be able to run your fuel blend on any diesel engine." (don't know how to paste two quotes into one post)

Hi guys. Can anyone with experience in blending diesel fuel help me out on this one?

I have access to a few hundred litres of dirty, oily kerosene per week for little effort. It is used as degreaser for parts cleaning so there will be some contaminants (watch out for TCE right BBD!) but typically grease, oil, road grime etc. I got a copy of the MSDS for the new product which states the boiling range is 150C-280C with a flash point > 61.5C and a kinematic viscosity < 7cSt @ 40C.

It would appear that if I clean it up and blend oil into it to get the viscosity right I can use it in my work trucks.

Excalibur - given the flash point is fairly high I shouldn't have the issues you mentioned above right? Our temperatures here average 10-30C with some colder and hotter days. I have a couple of 10 year old Isuzu 2 tonners, a new Isuzu 5 tonner and one 10 year old Isuzu 10 tonner.

BBD - Should I stick to a standard lube oil for the blending? I figured if I had access to heavy gear oil or even grease I could add less of it to the kero to match the viscosity. But I wonder if the kero and grease will stay blended or 'fall out' like bitumen does? Would long, 'fluffy' grease molecules be ok going through the engines? Some greases have soap (?) or other additives in them, would that be a concern?

Col, good find with the kerosene! With the boiling point range it has it will be very stable in my opinion. Compare that to what I've been blending with, which has a boiling point of 40'c. I dream of finding kero in the quantity you have access to.
If you were to centrifuge the kero, that would be the best thing. That fuel may not clean up clear and transparent but it most likely won't matter too much. It depends on what it's contaminated with. Filtering alone often doesn't remove the black color waste often is. If it's centrifuged/filter to 1 micron, it's a good as it needs to be however if there's lots and lots of free-carbon in the fuel it can soot the injectors. So really if it doesn't work because it soots injectors then the solution is to distill it. That would require heating to 150'c -280'c range and condensing the vapors.
So, having done blending for about 10years, I'm confident it's worth trying and I give it a high probability of success. A lot has been learnt about what you can get away with and it's still work in progress to some degree.
I don't know about grease as a blend component. Yes, it's said to have wax as a carrier for the lubricant. Start with oils, and the cleaner and lighter viscosity the better.
Perhaps hop over to BBDs' forum for lots of discussion, ideas, points of view, etc on blending.

[imakebiodiesel]

By coincidence I have just recently developed a simple cheap apparatus for measuring viscosity accurately in centistokes. It would be very useful to anyone who is blending different fuels. Essentially it is a transparent tube filled with liquid that you drop a small ball into. You time how long it takes the ball to fall 1 m and enter that time and the density of the liquid into Stokes Formula and you get the viscosity.

There is a more detailed description and discussion over on the biodiesel infopop forum at
Falling Ball Viscometer - Topic
I have tested my synthetic kerosene against commercial kerosene and have a match to within 1 decimal point.

[Beyond Biodiesel]

Hi guys. Can anyone with experience in blending diesel fuel help me out on this one?

I have access to a few hundred litres of dirty, oily kerosene per week for little effort. It is used as degreaser for parts cleaning so there will be some contaminants (watch out for TCE right BBD!) but typically grease, oil, road grime etc. I got a copy of the MSDS for the new product which states the boiling range is 150C-280C with a flash point > 61.5C and a kinematic viscosity < 7cSt @ 40C.

It would appear that if I clean it up and blend oil into it to get the viscosity right I can use it in my work trucks.

Excalibur - given the flash point is fairly high I shouldn't have the issues you mentioned above right? Our temperatures here average 10-30C with some colder and hotter days. I have a couple of 10 year old Isuzu 2 tonners, a new Isuzu 5 tonner and one 10 year old Isuzu 10 tonner.

BBD - Should I stick to a standard lube oil for the blending? I figured if I had access to heavy gear oil or even grease I could add less of it to the kero to match the viscosity. But I wonder if the kero and grease will stay blended or 'fall out' like bitumen does? Would long, 'fluffy' grease molecules be ok going through the engines? Some greases have soap (?) or other additives in them, would that be a concern?

Thanks heaps.
Col.

I agree with Excalibur, if the kerosene is not saturated with ash, or free carbon, turning it black, then, theoretically, it is much easier to filter a waste oil to turn it into a viable fuel, than to distill it. The only reason why I am distilling WMO is because just filtering was not enough to keep it from coking my injectors.

Excalibur's problem appears to be a vapor-lock issue that seems to be unique to his automobile, because few others have the same problems that he is reporting. Nonetheless, the issue of vapor-lock is with light fractions only. Kerosene will be too heavy a fraction to cause vapor-lock.

Nice falling ball viscosometer, imakebiodiesel. I have both a visgage, which is falling ball, and a set of vis-cups. I find the vis-cups easier to use in the field. I would check out your plans on Infopop, but I was banned from there for advocating blending gasoline with waste oils to make diesel fuel. They also ban people for burning WMO. I suppose plastic pyrolysis people will be banned from there as well.

[sunilkm153]

water bubbler

dear friend Excaliber
today i saw your blog nice work , there you show a water bubbler ( which I thought is one of the major safety equipment for a ideal pyrolysis unit) with a yellow cylinder inverted on one red cylinder would you please explain this design in detail



sunilkm153

[Col]

cooling the vapours in liquid and level maintenance

why is everyone trying to cool the gasses in condensors prior to entering the collection tanks, I intend to plumb the gas feed directly to the bottom of the collection tanks, then plumb the condensed fluid to a thermostatically controlled hydraulic cooler. I will have to always start the process with fluid in the tanks, but it will be much easier and more efficient to controll the temperature of the fluid that the gas will bubble through than to controll the temp of the gases directly. ultimately this is how a fractionating column works. they allow the gasses to bubble through fluid that is of the desired temperature, the desired fraction will then condense and remain with the fluid in that fraction. Is there any flaw in my thinking?

On an other matter, this unit shown will be both batch and continous feed, I Intend to run it while I work in the welding shop during the day. It will start out with a batch of plastic, that I intend to melt into wmo in the beginning, ( 20 L plastic pails that the oil comes in ) left over solvent and paint, and a bit of rubber from our scrap tires, then I intend to have an oil feed preheated by a coil in the exhast pipe, that will drip wmo and crude oil into the retort so that It may operate uninterupted for 8 to 10 hrs at a time. But I have a small problem, I have no Idea how to monitor the ammount of fluid in the retort after it is sealed up, I considered setting the unit up on a scale so that I may read the weight and adjust feed rate accordingly, anybody have any other suggestions?

Hi thissideup - how did you go piping the vapours through the fluid in your packed condensing tanks versus piping the vapours into a 'dry' section of the condenser to rise up into the packing? Did you achieve a quality product efficiently? Did you find this added to the internal pressure of the system, and did that have an impact on the required temperatures to complete the process? I am drawing my build now and am wondering which way to go.

As for maintaining a certain level in the retort maybe this would work - set a horizontal pipe at the desired oil level, passing from inside the retort out to another tank. This tank has a removable lid for checking on the level, and a quality floating valve similar to those used in a toilet cistern, but all metal. This tank can be made as small as is practical to fit the float valve in, 40L? The float valve is fed from a bulk oil drum which can be topped up as required. As the vapours pass from retort to condensers, oil flows from intermediary drum to retort and oil feeds from bulk drum to intermediary drum via float valve. The oil finds it's own level between intermediary drum and retort, this level is set by the float valve.

Potential issues - is it a problem having a non-closed retort? The horizontal pipe feeding top up oil to the retort would need to be long enough so that 450C heated oil does not make its way back to the intermediary drum where there would be air in the top of the tank. How about passing this pipe through a drum of cold water - would that do the trick? Would the internal pressure of the system (depending on how many times vapours were directed through liquid - diesel, kero and naptha condensers, water bubblers) push hot oil / vapours back along the pipe to the intermediary tank? Even if it did, passing the pipe through a drum of cold water should quench the heat and render it a non-issue.

Your retort looks great! Do you have any pictures of further work?

Col

[Col]

blending

Hi guys, thanks for your feedback, much appreciated. I'll have a look at BBD's forum for further info / ideas.

I have a mate who did some work at a local waste oil processing plant. He reckons these guys put $60K into trying to get kero to blend with waste grease to be sold as industrial burner fuel. Apparently they were having trouble getting the grease to stay in suspension after delivery to the customer, it would fall out into the bottom of the tank and lead to dramas. He says they abandoned the idea. I reckon if you gave $60K to some of the guys on this forum they'd soon figure out a way to keep the blend uniform. Surely even a simple circulating pump (and maybe a heater) on the customer's bulk tank would had to have come close to solving the issue? But I guess 'close enough' is not good enough and I only have one second hand comment to go off.

Cheers.
Col