How to turn plastic waste into diesel fuel cheaply

[Excalibur]

I need advice from the experts on condensers how do you calculate the temperature drop from distance of the length of pipe to each condenser.
example
condenser 1 350c
condenser 2 250c distance from condenser 1 4 feet
condenser 3 150c distance from from condenser 2 3 feet
Or there are just too many variables to make it that simple.
But I plan to use heater bands from 250c and 150c as 350 can use just simple insulation

chacowako, I think earlier you said you are aiming at making diesel and not interested in gasoline, therefore you can make this array somewhat simpler.
Two condenser vessels in series followed by a bubbler is what you can get away with. Even simpler would be one vessel for diesel plus bubbler but the downside is that gasoline would end up floating on the bubbler water, raising its' level and it becomes a pain to extract.
The setup works like this: the reflux is tuned to the correct workable temperature so that the maximum weight that exits is that of diesel fuel. Heat from the stream maintains the temperature of the diesel vessel and all that is required is about 60°C in there. A heat exchanger at the diesel vessel inlet quenches the stream as required so that the diesel vessels' heat can be regulated. The 60°C mentioned earlier forces any excessively light fractions to be driven off downstream, hence the need to capture these in condenser vessel#2.
The point of it is, is that diesel is a range of hydrocarbons some of which overlap with gasoline. So only the most volatile of these fractions need be extracted from the diesel to make it stable enough to use in a diesel vehicle.
Tuning the reflux is going to need a bit of trial and error but the temperature maintained in this does dictate the weight of the fuel that lands in the 1st condenser vessel. To put this in simple terms, if the fuel dropping into condenser#1 is too heavy then lower the reflux temperature. If the fuel is too light then raise the reflux temp. I suggest starting point be about 300°C -350°C range and tweak from there. All this assumes that everything about the retort and reflux is working in harmony, correctly proportioned and appropriated levels of retort heat energy are being applied.
HTH

[chacowako]

Excalibur Thanks for feedback now I understand your Orion drawing of how your condenser worked. I was wondering why there was only 2.

[dippy909]

Plastic Extruder

Gentleman
I have been away from my project for some time, I'v decided to make an automatic feed for the Plastic feedstock.

My retort has diesal burner blowing into a spiral bound system outside the. retort.

i was thinking of using the exhaust to heat the Plastic Feeder through a screw type mechanism .
Q's
1. can anyone supply a simple drawing of how to design a system,
The real query here is would I need to heat the Funnel feeding the extruder or just concentrate on heating the extruder element
2. Would I require a non return valve in case the feeder is running empty to stop The vapour stream entering the Feeder? If so any further suggestion's would be appreciated.
3. Would there be any problems of overheating the Feeder using the exhaust gases, how could we control the temperature- a manual/automatic wastegate ? or not required
4. Last question does anybody have any simple ideas of developing a plastic shredder ?

Thankyou

[kedigen]

reactor of 330 cm height. 127 cm diameter. Does 45 kW resistance enough?

[wheels]

Gentleman
I have been away from my project for some time, I'v decided to make an automatic feed for the Plastic feedstock.

My retort has diesal burner blowing into a spiral bound system outside the. retort.

i was thinking of using the exhaust to heat the Plastic Feeder through a screw type mechanism .
Q's
1. can anyone supply a simple drawing of how to design a system,
The real query here is would I need to heat the Funnel feeding the extruder or just concentrate on heating the extruder element
2. Would I require a non return valve in case the feeder is running empty to stop The vapour stream entering the Feeder? If so any further suggestion's would be appreciated.
3. Would there be any problems of overheating the Feeder using the exhaust gases, how could we control the temperature- a manual/automatic wastegate ? or not required
4. Last question does anybody have any simple ideas of developing a plastic shredder ?

Thankyou

Very dangerous ground. If you can not work out the design and issues yourself, do not attempt it.
You need a very specially designed screw/auger. You need to be able to expel all oxygen that went into the feed with the plastic particles. You have to be able to contain all the gasses produced, as the screw heats the plastic as it gets closer to the Retort. It requires some well designed, highly engineered and complex controlled machinery.

[wheels]

reactor of 330 cm height. 127 cm diameter. Does 45 kW resistance enough?

I doubt it. I am using 30Kw to heat a vessel just a fraction of that size. It takes a specific amount of energy per Kg to Pyrolyze Plastics and do that efficiently. The amount of energy varies between plastic types, but it takes the following just to melt these Plastics. It takes even more energy to take plastic right through to Pyrolysis.
HDPE= 250,000 J/kg
LDPE= 200,000 J/kg
You also have to take into account the Steel the vessel is made from. That has to be heated to temperature first. That takes energy as well and then you havr to take into account the amount of steel exposed to Air. This is where heat will transfer and escape and that heat must be replaced all the time. The bigger you go, the more chance of loss and the heat required to do the job has to increase exponentially. This is because Area/Volume increases exponentially.

[wheels]

HDPE= 250,000 J/kg
LDPE= 200,000 J/kg
You also have to take into account the Steel the vessel is made from.

I thought i should clarify that last statement. I meant how thick the Steel is, which will be mass and mass will take time to heat to temperature.

Also, this formula may help for you to work out the energy required.
P(W) = E(J) / t(s)
So,
watt = joule / second
or,
W = J / s
To work out how many Watts you will need for a Minute, x the Sum by 60 and then 60 again if you want the Sum per hr. Per hr would be helpful to work out against the amount of plastic you are wanting to process per hr. You would want a Heat source with more output than what you work out in theory, because there will be some variables. Like how much moisture is in the plastic, in the air, Air temp, Steel thickness, heat loss through insulation, heat loss traveling through pipe work with Hydrocarbon vapors and heat loss due to inefficiency of heat transfer, which you will have escape out through the Flu.

[chacowako]

can you mix activated carbon and zeolite?
would the zeolite become useless?

[wheels]

can you mix activated carbon and zeolite?
would the zeolite become useless?

Yes you can mix the two, but why?? What are you trying to achieve? Activated Carbon acts purely a "Filter". It does not act as a Catalyst. Zeolite can also be used as a filter in certain situations and in specific ways of use, but more commonly, it is used as a Catalyst. And in saying that, it is a particular type of Zeolite that tends to work the best as that Catalyst, although any of the other Zeolites will do better than nothing.
The next question that needs asking is, what is happening to your end product that you think you may need a catalyst?

[Piet]

Can anybody tell me at what temperature wax is made and and what temperature diesel is made either in the retort or reflux.
Thanks, Piet.

[Excalibur]

Can anybody tell me at what temperature wax is made and and what temperature diesel is made either in the retort or reflux.
Thanks, Piet.

Early on, Jetijs discovered that waxing occurred when the reflux temperature was allowed to run too high. The retort temperature should be at a point where the contents is simmering in a controlled fashion and not too vigorous. The reflux should be at a point below the retort temperature else there is no refluxing. Exact temperatures will vary depending on design and feedstock but as a starting point, retort 400°C /reflux 300°C and tune from there. Weight of product produced and wax avoidance will ultimately dictate the reflux temperature.
HTH

[wheels]

Early on, Jetijs discovered that waxing occurred when the reflux temperature was allowed to run too high. The retort temperature should be at a point where the contents is simmering in a controlled fashion and not too vigorous. The reflux should be at a point below the retort temperature else there is no refluxing. Exact temperatures will vary depending on design and feedstock but as a starting point, retort 400°C /reflux 300°C and tune from there. Weight of product produced and wax avoidance will ultimately dictate the reflux temperature.
HTH

I am doing a bit of guessing here, but wax may possibly be the wrong description. It is possible that another thing is taking place causing the liquid to solidify. This idea came about from Excalibur and I discussing a slightly different situation and he discovered that a particular Hydrocarbon when at room temperature, existed in a solid crystal form. It did not melt to a liquid till 70degC. I made a comment then, "I wonder what that does to the other liquids once the temperature drops below 70Deg". I am sorry I have forgotten the name of the Hydrocarbon, so Excalibur, can you remind me again please?
Anyway, what surprised me was that this Hydrocarbon is a short chain one. These very short chains can be formed by the types of Plastic's and to high a temperature causing over cracking. Cracking is caused by anyone or a combination of.... Heat, Time in the Retort, what weights are cycled back from reflux and Catalyst. So if the desired end product is wanted as a Diesel weight Fuel, then it is quite possible that the Plastics are being "overcooked" in the process. Hence jetji's comment about having a waxing problem at high temps. It is possible that a high proportion of this crystal form of Hydrocarbon is causing the liquid to solidify to a consistency of wax.
A lot of trial and error maybe required, but I suggest changing a few of the processes. Firstly, as it is desirable to have the process go as fast and efficiently as possible, plus we don't all have perfect heat control, I suggest that perhaps the removal of the catalyst (if one is used) be tried first. Second, the temperature of the reflux vessel is possibly more important than the Retort temp. But it is possible the temperature may need to be varied either up or down. That is going to be a little trial and error. Temperature of reflux will affect the weight of fractions sent back to retort as well as what continues on through the system, as well as time the Hydrocarbons remain within the Reflux vessel. Any vessel that is heated will affect Hydrocarbons that have a Boiling point below that heated Vessel temp. Once Fractions are heated to above boiling point, they can under go cracking. Obviously the hotter the temp, the more likely a chain will crack.
This is however, just an idea. I could be wrong, but most certainly if you are having a waxing problem, then try changing a few of the suggestions and report back on what was found.

[Excalibur]

Wheels, it was:
Naphthalene, (not to be confused with naphtha or naphthene) is an organic compound with formula C10-H8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs.

What surprises me was the reflux temperature of 150°C Jetijs eventually used to avoid the wax. Later, imakebiodiesel reported a reflux temperature of 350°C to make diesel. So why the massive discrepancy in temperatures I wondered. Jetijs showed good pics of the waxed fuel and documented the details. I believe it comes back to differences in plant setup plus operating parameters.
BTW Wheels, I have at least 10 liters of the wax left from my first ever failed experiment. It looks like the PE it was made from but has lost the ability to bond as a proper solid. It is soft and waxy to touch and I thought about using it as furniture polish. No pungent mothball odor at all. See it sometime.

[sunilkm153]

Dear friends

is any one utilizing uncondensed (remaining) gases in a diffferent manner that means other then heating the retort like to produce electricity or any other novel idea



all in advance

[rozier56]

gases

My idea is to use the gas as plastic melting process.Then you can melt the 25lt etc cans and bulky items.We are currently building one which will make up brick size blocks which are easy to load into retort.