I have to produce oil from polyethylene pyrolysis.
I do not have a feeding system so I put plastic inside the reactor and after that started heating from room temp to 520C.
Are you allowing the volatiles evolved from pyrolysis to pass through a condensing system longer enough? Maybe the gas contains a large amount of condensable volatiles which are not being condensed.
If you want to have more volatile matters, you need to do the pyrolysis as fast as possible. Otherwise, you are in favour of carbonaceous residues (but very few in the case of PE, which mostly produces gases, as you already observed). I confirm that the condensable vapours need to be trapped at the outlet of the pyrolysis reactor. But you really have to increase the heating rate. If your system doesn't allow to heat faster, you can preheat the oven at the desired temperature, and then push the sample in the heated zone. Of course, when I mean "the sample", it means "sample inside its tube flushed by inert gas".
Alain
Dear all;
besides temperature, the catalysts type and concentration has almost the predominant influence on the pyrolysis products. I have assisted a master project in which different products forms are possible, including low hydrocarbon liquids (I am not sure if they have an oil character). There are pleinty of literature data on the pyrolysis of polyolefins, and especially PE. The production of gases is almost inevitable, but may be lowered to a great extent. Sooner I will provide with some bibliographic material on this topic. Regards
If you are applying pyrolysis on LDPE, then my suggestion is to do it in a closed batch reactor at no more than 425 oC in order to get oils. If the temperature gets higher than that, then this will reduce the amount of oils & increase the amounts of gaseous products as well as char. Of course, waxy products are possible upon hydrolysis of LDPE & these materials have around 20 carbon chains "similar to eicosane which is the main ingredient of the commercial cheap paraffin wax" .
At first, I do set of experiments by thermal cracking without using any type of catalyst and I use HDPE
Dear all,
catalysts are used to lower the activation energy, that is to say to allow working at lower thermal input for low onset of the reaction (in your case pyrolysis), so my advise is try using catalysts for better mastering of the reaction products. I have a lot of documents on this topic, but since we are allowed for no more that 10 attachments, here are some papers with the hope that they will bring a certain feedback to this question. Regards
You should get oils at the end not wax. Can you please elaborate about your feed n reaction conditions?
I do not have feeding system so I put PE waste when I start experiment and after that close the reactor and then heating. I open nitrogen flow rate when I see the temperature of the reactor reach to 400 degree.
Dear Faten
We worked in PET waste n conducted Pyro lysis n worked fine. All polyalkenes provided good results to us. But we used different reagents like catalysts n crude also.
Dear all;
for a hydrocarbon backbone usually a catalysts is needed for many reasons, which is not the case of PET in which the ester linkage has its effect on the ease of chaine depolymerization (cracking or breaking). I think the analogy between PE and PET in the context of pyrolysis is quite irrealistic. Regard
Please provide a schematic of your set-up. It is easier to suspect the resoan of getting only wax.
If you have overcame the challenge then beneficial to know your solution.
Faten Hameed Kamil Greetings! I am also having the same problem during pyrolysis of PE for the production of oil but only Wax is being produced.
Can you please tell me, how you solved this problem?
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