How to turn plastic waste into diesel fuel cheaply

[wheels]

Hi Wheels.
One of the great benefits of asking questions and sharing information is not so we can copy blindly without an understanding of the system, but so we can confirm or correct and direct our thoughts on our system. Asking someone with practical, hands on experience in exactly the area of work in which we are about to engage, in my mind, is better than going to an engineer for such a small system. I do not think I could find or afford an engineer with experience in doing what we are learning here.
So, no, I have no properly designed system as far as engineering goes. But the system is based on learning and experience from numerous people over years of real-life experience, both on this forum, and from other relationships I have with people. One person I know is operating a commercial system with throughput of 1000L per hour. He has been happy to talk with me about and show me his system in operation, but in confidence. He contracted an engineer with experience and spent big bucks getting to where he is at the moment. It's interesting to note that he runs his system at pressure, one benefit is that oxygen can't get into the system while there is pressure. So while I have not done calculations on flows and cooling etc we have access to real life experience to guide us. I am putting together a small 20L retort right now and intend to put temperature and pressure gauges at numerous points along the system and sight glasses and gas flow indicators also. As I learn in depth about the system I will upscale.
Thank you for your input to date, and I look forward to what we can all help each other with as we go.
Col

Hi Col, I was referring to someone that was going to jump in the Deep end and build some huge thing as his first off machine and he was asking technical questions that I really don't think anyone here could or should give answers to. it would be far too difficult and dangerous to advise without knowing many more details and even then, it would require an expert Design Engineer. As you know from your Friend with the big plant, it does require some major expert engineering knowledge to design such a plant. OK this guy was not that big, but he was going to start at 500 or 100ltr retort. That is a whole different level. It is not just about what plastics and what heat required anymore, but questions like Pumps and Valves and Sensors and cooling flows and so on. Another example was someone with the 45Kw of heating and then he found his supply could not cope with the demand. Things like that require proper design. I am glad I am not paying his Electric Bill.

[David007]

I have finally read all the way through. Wow, what an epic read.
I have some worries with some of the designs that have been built
A couple of small points to consider. All Tube/Pipe sizes need to be a reasonably decent diameter for two reasons. We do not want back pressures at all. The gasses must flow freely. We do not want any chance of blockage. We do not want to high a speed of gas through the Tubes as this reduces time for coalescing in the distilling vessels and in the cooling though any heat exchangers.
Flash back arrester's and pressure relief. This is slightly concerning also. You need more than just a little pressure relief valve that was designed for nothing more than clean gas such as a Propane Bottle. The Valve needs to be able to relieve all pressure in an emergency and maintaining that flow volume till the vessel cools enough to stop operating. One of the big issues we have is that the Gasses and condensates in the vessel are thick and dirty with Carbon particles and will block any small pressure relief valve in an instant. I suggest people take a look around for large Steam relief valves that have a simple valve face that is lifted under pressure. It needs to operate simply, cleanly and with at least restriction as possible. A small modification will be required to reduce the pressure in which it will release. they work by a simple weight sitting above the seat and that weight would need to be dramatically reduced.
I do not know of any large diameter rupture disk available, but not saying there is not one. But a small relief is no better than no release at all.

Another area of concern is that I think many readers here have Dollar signs in their eyes. Many seem to view this as turning straw into Gold. It simply is not the case. You can not make money from turning waste plastic into Oil, if the simple fact of obtaining Oil/fuel from Waste plastic is the sole reason. Even less so if you are buying the plastic feedstock. You have to have some other motivation behind doing this. So in other words, the Oil/Fuel produced is the added benefit, rather than the main reason. It will always be cheaper to go fill up from the Local Fuel Supplier. So perhaps the cost of dumping the Plastic Waste is expensive and you can now add that saving to the Oil produced.
There has been a great deal of research in Pyrolysis. It is not a new technology, it is as old as the Hills. Many prominent Universities have published a lot of facts and figure on the procedure and the first major point is, the process has about a 20% efficiency. That means that you get a 20% return on Energy, from what you put in. Said in another way, it takes about 4 to 5 barrels of Oil(as seen as worth of energy) to produce one Barrel of Pyrolysed Oil (as seen as energy).

Another area I just want to make really clear. Others have made the same kind of comments. SAFETY!!!
There are some designs that are far from safe. You need to remember one important point. You are heating a very Volatile/Flammable product to over 400DegC in a Metal Vessel and in most cases, that vessel is sitting on top of some form of a naked flame, taking the flame contact point of that vessel well into extremely high temperature figures. A very simple failure in some area WILL result in a catastrophic failure and can Kill or seriously harm. Not only is there a danger to ones self, there is a danger to your property your Neighbor and their Property. I was shocked to see one of these units inside someones Home on top of the Cooking Top
Please think about Safety and think through all the "what if's".
I am also slightly concerned at the larger scale operations that have been set up. Once you go above the small sizes we have represented here on this Forum, you enter a whole new realm of issues. Things to consider are Materials you are constructing from. You may use SST for instance. But what kind of SST is very important. How that Metal has been welded and on going testing of those Welds. Many large scale operations around the World have failed in horrific explosions killing people because a Weld has cracked and Oxygen has entered the Vessel. My big concern is that asking here questions about pipe sizes and flows and cooling etc means you have no properly designed system and no clue as to what you are operating. Once you get into a large machine, there needs to be some properly Engineered design into flow, heat exchanging, adding feedstock and removing the Carbon waste, which by the way, can be extremely hazardous in itself.

hi wheels, this forume is so nice, but i think a summary.
now you are in other level -expert
if you build now your "refinery" how you answer this question??

NEW MEMBER WHEN FINISH TO READ, FORUM ANSWER THIS QUESTIONNAIRE, "HOW YOU BUILD IT" !!!!
(for all answer, and attach and link to illustrated, the answer)
1
1-a- temperature of reactor?
1-b- tem. of diesel
1-c- tem. paraffin, wax
1-d- tem. of kerosine
1-e- tem. of petrol (gasoline)

2- how is best catalyse about you, what have learn about catalyse?

3- what can do for make more:
3-a- diesel,
3-b- more paraffin, wax????
3-c- kerosine, or petrol (gasoline)???

4- why si best design for you??

5- who is good instrument to use (and chip)
5-a- electrical,
5-b- pid, digital temperature controller
5-c- thermo.
5-d- pressure valve

6- formula for make fire brick (non to buy for cooking it in your perssonial forme)???

[Col]

My big concern is that asking here questions about pipe sizes and flows and cooling etc means you have no properly designed system and no clue as to what you are operating. Once you get into a large machine, there needs to be some properly Engineered design into flow, heat exchanging, adding feedstock and removing the Carbon waste, which by the way, can be extremely hazardous in itself.

Hi Wheels.
One of the great benefits of asking questions and sharing information is not so we can copy blindly without an understanding of the system, but so we can confirm or correct and direct our thoughts on our system. Asking someone with practical, hands on experience in exactly the area of work in which we are about to engage, in my mind, is better than going to an engineer for such a small system. I do not think I could find or afford an engineer with experience in doing what we are learning here.
So, no, I have no properly designed system as far as engineering goes. But the system is based on learning and experience from numerous people over years of real-life experience, both on this forum, and from other relationships I have with people. One person I know is operating a commercial system with throughput of 1000L per hour. He has been happy to talk with me about and show me his system in operation, but in confidence. He contracted an engineer with experience and spent big bucks getting to where he is at the moment. It's interesting to note that he runs his system at pressure, one benefit is that oxygen can't get into the system while there is pressure. So while I have not done calculations on flows and cooling etc we have access to real life experience to guide us. I am putting together a small 20L retort right now and intend to put temperature and pressure gauges at numerous points along the system and sight glasses and gas flow indicators also. As I learn in depth about the system I will upscale.
Thank you for your input to date, and I look forward to what we can all help each other with as we go.
Col

[wheels]

Finished the thread

I have finally read all the way through. Wow, what an epic read.
I have some worries with some of the designs that have been built
A couple of small points to consider. All Tube/Pipe sizes need to be a reasonably decent diameter for two reasons. We do not want back pressures at all. The gasses must flow freely. We do not want any chance of blockage. We do not want to high a speed of gas through the Tubes as this reduces time for coalescing in the distilling vessels and in the cooling though any heat exchangers.
Flash back arrester's and pressure relief. This is slightly concerning also. You need more than just a little pressure relief valve that was designed for nothing more than clean gas such as a Propane Bottle. The Valve needs to be able to relieve all pressure in an emergency and maintaining that flow volume till the vessel cools enough to stop operating. One of the big issues we have is that the Gasses and condensates in the vessel are thick and dirty with Carbon particles and will block any small pressure relief valve in an instant. I suggest people take a look around for large Steam relief valves that have a simple valve face that is lifted under pressure. It needs to operate simply, cleanly and with at least restriction as possible. A small modification will be required to reduce the pressure in which it will release. they work by a simple weight sitting above the seat and that weight would need to be dramatically reduced.
I do not know of any large diameter rupture disk available, but not saying there is not one. But a small relief is no better than no release at all.

Another area of concern is that I think many readers here have Dollar signs in their eyes. Many seem to view this as turning straw into Gold. It simply is not the case. You can not make money from turning waste plastic into Oil, if the simple fact of obtaining Oil/fuel from Waste plastic is the sole reason. Even less so if you are buying the plastic feedstock. You have to have some other motivation behind doing this. So in other words, the Oil/Fuel produced is the added benefit, rather than the main reason. It will always be cheaper to go fill up from the Local Fuel Supplier. So perhaps the cost of dumping the Plastic Waste is expensive and you can now add that saving to the Oil produced.
There has been a great deal of research in Pyrolysis. It is not a new technology, it is as old as the Hills. Many prominent Universities have published a lot of facts and figure on the procedure and the first major point is, the process has about a 20% efficiency. That means that you get a 20% return on Energy, from what you put in. Said in another way, it takes about 4 to 5 barrels of Oil(as seen as worth of energy) to produce one Barrel of Pyrolysed Oil (as seen as energy).

Another area I just want to make really clear. Others have made the same kind of comments. SAFETY!!!
There are some designs that are far from safe. You need to remember one important point. You are heating a very Volatile/Flammable product to over 400DegC in a Metal Vessel and in most cases, that vessel is sitting on top of some form of a naked flame, taking the flame contact point of that vessel well into extremely high temperature figures. A very simple failure in some area WILL result in a catastrophic failure and can Kill or seriously harm. Not only is there a danger to ones self, there is a danger to your property your Neighbor and their Property. I was shocked to see one of these units inside someones Home on top of the Cooking Top
Please think about Safety and think through all the "what if's".
I am also slightly concerned at the larger scale operations that have been set up. Once you go above the small sizes we have represented here on this Forum, you enter a whole new realm of issues. Things to consider are Materials you are constructing from. You may use SST for instance. But what kind of SST is very important. How that Metal has been welded and on going testing of those Welds. Many large scale operations around the World have failed in horrific explosions killing people because a Weld has cracked and Oxygen has entered the Vessel. My big concern is that asking here questions about pipe sizes and flows and cooling etc means you have no properly designed system and no clue as to what you are operating. Once you get into a large machine, there needs to be some properly Engineered design into flow, heat exchanging, adding feedstock and removing the Carbon waste, which by the way, can be extremely hazardous in itself.

[David007]

no big problem, how make better??

Yes keeping to PP and PE plastics is wise as it makes for less problems.

As for shredding the Plastics, there is no simple easy answer. It is a difficult material to cut up and it takes a lot of Hp.

i think non is big problem, but need some other ide..
Plactic (HDPE) shreding for ... - YouTube
Homemade Shredder - YouTube

[wheels]

i build my "refinery" for plastic, get only pp/pe 10 kg is about 1 m3,
i try to shredder is impossible !!!!!!!!!!!!!!!!
for some day i build it but.....i cant shredder is so...pff
please any idea

Yes keeping to PP and PE plastics is wise as it makes for less problems.

As for shredding the Plastics, there is no simple easy answer. It is a difficult material to cut up and it takes a lot of Hp.

[David007]

how you shredder!!!!!

i build my "refinery" for plastic, get only pp/pe 10 kg is about 1 m3,
i try to shredder is impossible !!!!!!!!!!!!!!!!
for some day i build it but.....i cant shredder is so...pff
please any idea

[wheels]

There are many end of cycle PET scrap available. What can be they put to use.

Are you asking that question in relation to us Pyrolysing PET scrap, or are you asking what other uses it can be used for by other Industries. If it is "Other Industries, it can be used for all that I have listed before and many other products made from Polyethelyne.
If the question is about us melting it, the Plastic has many disadvantages and it is not worth using. There is one major problem with PET, it turns from it's Solid Form, straight to Gas at about 260DegC. You get no liquids, just Gas. But the danger is that any Gas in any part of your Machine will turn back to a White Crystal as soon as temperatures below 260DegC are met. As most of the Plant other than the Retort, is below 260Deg, this will result in the entire Plant becoming blocked with a dense White Crystal called Terephthalic Acid.

[David007]

Quote:
Originally Posted by David007 View Post
hi if put inside of reactor, out pippe from hho generator, (idrogen)
Polyethylene terephthalate categoria I

(C10H8O4)n + n4H2 = nC10H8 + nH2O

i think can cooking C10H8 i think this is hidrocarbur + H2O and water vaporize
in condesser can make diesel+water rpt again the proces to separate disel from water!!!

what you think?
Hi David007. OK so if I can decipher your post correctly, you are asking if you can put the output of a hydrogen generator into your Reactor Vessel, thus flooding the Vessel with Hydrogen.
The answer to that is yes, as long as you do NOT allow any Oxygen to enter the Vessel. There is no more potent Explosive than Hydrogen and Oxygen.

The second question looks like you are thinking that PET (C10H8O4) reacting with N4H2 would give you NC10H8 + NH2O. Well N4H2 is not pure Hydrogen. In fact it is about 96.5% Nitrogen and 3.5% Hydrogen. Plus that reaction you have described means the Hydrogen is reacting with Oxygen and producing the H2O or water. It takes a very loud and a Violent Bang to make H2O like that. That is Combustion and the first problem is you need about 15% Oxygen to support combustion and Oxygen is the last thing you want in the Vessel.

However, all that aside, PET can be Pyrolysed. There is Oxygen in it's Formulae, but the Oxygen is decomposed by the Terephthalac Acid.
However it does not produce any Liquid. It decomposes to mostly Gas. You will not get any liquid Fuel from it.
Also PET which is Polyester, is a sort after commodity and can fetch a very high price. It is used to make Polyester Fibres for Carpets, Clothing, Maylar and Rope. It simply is not a Plastic that is worth spending energy on, it is better to recycle it.
I hope that is understandable to you.


There are many end of cycle PET scrap available. What can be they put to use.

hi pravin, i not i am chimical expert, but i think i know the hydrogen is more power element 120-140 MJ / kg and petrol or diesel about 40 - 45 Mj / kg.

Potere calorifico - Wikipedia

Ok i understande non use PET and hydrogen!!!!

but what happened if i put Hydrogen in PE/PP or 2,4,5,6
i think make more power fuel, this fuel have more octan???


or the free carbon inside of Reactor Vessel + hydrogen can give me more fuel???

[pravin]

Quote:
Originally Posted by David007 View Post
hi if put inside of reactor, out pippe from hho generator, (idrogen)
Polyethylene terephthalate categoria I

(C10H8O4)n + n4H2 = nC10H8 + nH2O

i think can cooking C10H8 i think this is hidrocarbur + H2O and water vaporize
in condesser can make diesel+water rpt again the proces to separate disel from water!!!

what you think?
Hi David007. OK so if I can decipher your post correctly, you are asking if you can put the output of a hydrogen generator into your Reactor Vessel, thus flooding the Vessel with Hydrogen.
The answer to that is yes, as long as you do NOT allow any Oxygen to enter the Vessel. There is no more potent Explosive than Hydrogen and Oxygen.

The second question looks like you are thinking that PET (C10H8O4) reacting with N4H2 would give you NC10H8 + NH2O. Well N4H2 is not pure Hydrogen. In fact it is about 96.5% Nitrogen and 3.5% Hydrogen. Plus that reaction you have described means the Hydrogen is reacting with Oxygen and producing the H2O or water. It takes a very loud and a Violent Bang to make H2O like that. That is Combustion and the first problem is you need about 15% Oxygen to support combustion and Oxygen is the last thing you want in the Vessel.

However, all that aside, PET can be Pyrolysed. There is Oxygen in it's Formulae, but the Oxygen is decomposed by the Terephthalac Acid.
However it does not produce any Liquid. It decomposes to mostly Gas. You will not get any liquid Fuel from it.
Also PET which is Polyester, is a sort after commodity and can fetch a very high price. It is used to make Polyester Fibres for Carpets, Clothing, Maylar and Rope. It simply is not a Plastic that is worth spending energy on, it is better to recycle it.
I hope that is understandable to you.


There are many end of cycle PET scrap available. What can be they put to use.

[wheels]

I haven't tried the red bricks though I do have some old ones here which I've been eying up. Also some terracotta pots and some old drainage pipes in similar looking terracotta material. No shortage..
A rather interesting phenomena about the old terracotta pieces I took out of the reflux is they burn like a "little Lucifer fire starter". The terracotta looked totally black and sooted but I put a gas torch on it and they kept burning and burning. There must be a lot of diesel/oil soaked in.

Yes in some large commercial operations, they keep rotating the Catalyst for just that reason. The Material just blokes up with Carbon and gunk and loses effectiveness. The Material is dropped to a Bed usually of very Hot Sand(about 800degC) and Oxygen is pumped in to Burn off the Carbon and contaminants and then it is brought back to the top to act as a Catalyst again.

[Excalibur]

Excalibur, have you tried Red House Bricks as a Catalyst? I don't know just exactly what kind of Clay they are made from. But it could be similar to Terracotta and I imagine much cheaper finding some old Bricks rather than buying a Pot. Just break them into pieces and bobs your uncle.

I haven't tried the red bricks though I do have some old ones here which I've been eyeing up. Also some terracotta pots and some old drainage pipes in similar looking terracotta material. No shortage..
A rather interesting phenomena about the old terracotta pieces I took out of the reflux is they burn like a "little Lucifer fire starter". The terracotta looked totally black and sooted but I put a gas torch on it and they kept burning and burning. There must be a lot of diesel/oil soaked in.

[wheels]

When I use catalyst, it is put in the reflux. My connecting pipe between reflux and retort is 75mm. I install a stainless perforated plate to prevent catalyst falling into the retort or plugging the connecting pipe. It is positioned part way up the reflux. The terracotta is randomly broken into pieces so there is plenty of gaps when stacked inside the reflux. It gives the gases a kind of labyrinth. Take care that there is never a situation where the retort can accidentally build up pressure!
I hope this helps

Excalibur, have you tried Red House Bricks as a Catalyst? I don't know just exactly what kind of Clay they are made from. But it could be similar to Terracotta and I imagine much cheaper finding some old Bricks rather than buying a Pot. Just break them into pieces and bobs your uncle.

[wheels]

If you leave the Fuels to settle, say overnight, the water will separate out pretty well and then you can either drain it off, feed it through a water separating Fuel filter, or use the absorbent crystals. The Crystals are too slow at absorbing to bother sprinkling it trough the fuel.

[Excalibur]

Thanks Excalibur and Wheels. So I think it is safe to assume the Sodium Polyacrylate is inert as far as the hydrocarbons go and leaves no by-product. The product available in garden stores is as good as any other?
As for the crystals not absorbing suspended water - if the fuel were trickled through the crystals it should stand a good chance of absorbing suspended water. Does it take the water up quickly or does it need a longer contact time?

I haven't tested any others so I don't have anything to compare. The test was impressive in that the oil tested perfectly by Hot-Pan-Test at the conclusion. It took some time, perhaps several days from memory. In the pics on DIYDiesel, the sample on the left was wvo + water shaken into emulsion, then Sodium Polyacrylate added. The sample to the right had already been through the process. The Sodium Polyacrylate tends toward clumping together when hydrated, however flecks of S.P. are visible in the top of the sample jar to the right.
From the small amount of testing I did, I'd agree it takes time to absorb.
I plan to put some into my diesel tripod holding tank over coming weeks. I need to make the S.P. retrievable, perhaps containerized. I'll be updating DIYDiesel once I get moving on the idea.