DIY Plastic to Oil

Intro: DIY Plastic to Oil

"Till date nothing has proven to be a truly effective or environmentally responsible solution to the burgeoning global landfill problem. In fact, many existing solutions have been just the opposite: costly, energy inefficient or equally as harmful to the environment as the plastic itself. "

It is only now, that with the evolving pyrolysis technology, there is a solution that is remarkably simple, economically viable and "green" as well.

Pyrolysis is a thermochemical decomposition of organic material at elevated temperature without the participation of oxygen. In this process long polymer molecules are broken down into shorter chains of hydrocarbons with the help of heat and pressure. You can learn more about this process here: How to make oil from plastic

Some benefits of pyrolysis are that the process does not generate harmful pollutants and that the by-products can be used as fuel for running the plant. In the case of plastic, some of the valuable fuels and solvents that can be extracted through waste plastic pyrolysis are fuels like gasoline, kerosene, diesel, and high-value ones like benzene, toluene and xylene. And a kilo of waste (typically PP) can yield upto a litre of fuel whereas the incineration of the same quantity of plastic would produce 3 kilos of CO2!

This technology is growing in popularity and in demand. Commercial machines for home are still expensive. But with the following method, you can convert waste plastic to fuel all by yourself!

If you like this project, do vote for it!

STEP 1: Procedure

WARNING:

You will be working with highly inflammable substances. So do take the following precautions:

• Avoid inhaling the potentially harmful fumes
• Keep the fumes, produced in the reaction, away from fire and from electrical points
• Work in well ventilated spaces
• Keep some water and a fire extinguisher on stand-by in case of an accident

Construction of prototype pyrolysis reactor

1. Build a robust leak-proof reactor chamber
2. Build a condensation tube of copper, steel, or aluminium
3. Build a system for monitoring the temperature of the feed
4. Build a system to efficiently condense and collect the mixture of products

STEP 2: Build the Reactor

Before getting down to work, first decide the scale of your setup.

Ideally, 1 kg of plastic can produce 1 kg of fuel. For getting a good yield, you can use polypropylene i.e. any plastic product with the mark PP or '5'.

The reactor that I built has a capacity of about 100g.

So while selecting the container for your reactor, keep in mind the following considerations:

• It must be a robust metal container
• Its shape will affect the reaction speed, intensity and chemistry
• It must be easily openable and cleanable, yet...it MUST be perfectly leak-proof!

I used a stainless steel vessel and clamped it with a bolted aluminum strip. Next I drilled a hole in the centre of the lid for the outlet of the fuel vapour.

STEP 3: Condensing Energy

Back in the reactor, the plastic is converted to vapourized fuel above 400C.

You need to convert this vapour to liquid by passing it through a condenser. Once again, it needs to be robust, heat resistant and leak-proof. I used copper pipes (used as condensate piping in A/Cs and refrigerators) but you can you aluminium or steel.

The length of the condenser may not be sufficient for the circulating water to bring the 400C vapour to room temperature. So you'll need to further bubble it into water and then seperate the floating oil from the denser water. Let me know if you come up with a smarter way for doing this!

STEP 4: Start Producing Black Gold

Once you are done with the construction work, start the fascinating process of converting trash to black gold!

Here's how:

1. Collect some waste plastic items and shred them to pieces for faster and better reaction

2. Seal the shredded plastic tightly in the reactor chamber

3. Setup the equipment on your stove and turn on the inlet water flow

4. Turn on the stove, stand back, and watch the spectacle!

Initially you'll see fumes flowing out of the condenser, then drops will trickle, and finally you'll have a stream of usable oil flowing out! At the end of the reaction, when you open the chamber that was initially full, you'll be surprised to find it empty, only charred.

The trash disappears and all you are left with is usable oil of high calorific value. Light the obtained fuel and witness it burn flawlessly and for long! If you want to obtain refined usable products from this mixture, you can do so by careful fractional distillation. Although few people can extract the different product of pyrolysis, we successfully did! After successive distillations, we extracted four distinct products, which on the basis of boiling point, odour and calorific values, were concluded to be benzene, toluene and even a mixture similar to diesel!

Waste is a misplaced resource...your trashcan is a treasure chest.

Comments

[dudewhy]

Benzene and Toluene are both very toxic, Benzene is also a carcinogen.

[MateaC1]

Then, stay away and do nothing !

[dboccuti]

Simple question, but important one - is there a net positive output? In other words, does it take more energy to heat the container than the energy contained in the product? If not, why on earth would you do this other than as a demonstration of pyrolysis? Just wasting energy.

[bgoldberg1]

According to google, the energy efficiency of pyrolysis ranges from 59.4% to 66.0%

If you choose to burn some of the gas or liquid to do the conversion, then about a third of your product must be burnt.

Alternatives to combustion are electrical resistance or concentrated solar or a fire syringe / heat pump.

To DIY a heat pump pyrolysis reactor, use an engine as the "reaction chamber."

First, swap out the starter motor for something designed for continuous operation.

Into the engine's intake manifold, feed a carefully controlled mix of O2 and recirculated pyrolysis gas.

Wet mill the plastic with some recirculated pyrolysis oil, heat it if it's too viscous, and pump it through the engine's fuel injectors into the cylinders.

When the spark ignites it, just enough of the hot compressed gas will burn to quickly heat the liquid and the plastic in the liquid to 1000C, which causes said plastic to "flash pyrolyze." Because pyrolysis is endothermic, this will cool the gas slightly.

Pass the stuff coming out the engine exhaust through a cyclone to separate the gas from the liquid (oil). Some of that oil is used to wet mill the plastic, the rest is your main product. Some of that gas is recirculated into the intake, while the rest, a mix of valuable and valueless gasses, is your secondary product.

Both products need to be distilled, obviously.

Using air instead of O2 saves the cost of a concentrator, but dilutes the gas produced with worthless N2 and NOx.

Soot needs to be dealt with, and I hope no DIYer ruins a catalytic converter by not removing said cat.

Because flash pyrolysis is almost but not quite instant, the cyclone separator should be have enough volume to give the gas and liquid moving through it a dwell time of 0.2 seconds.

The throughput can be controlled by the speed of the electric motor we are using to spin the engine.

[dboccuti]

Hi bgoldberg! Was your response generated by ChatGPT or other AI? Sort of seems that way. Thanks

[dboccuti]

If the input energy was renewable (solar, wind) it would make more sense as a recycling process.

[byllcolette]

Can a pressure cooker be used as a container?

[dboccuti]

NO, pressure cooker has a rubber gasket

[nalininahagamkar79]

yes

[ialjafreh]

No we can't used pressure cooker as container

[ialjafreh]

Fin .we are interested in since

[ialjafreh]

Ok well be positive and constructive

[GHPS Hariharapura]

Hello sir can u please tell where and how to purchase the entire kit if available

[Imperar]

How much energy (kWh or MJ) is required to turn 1kg of plastic into oil?

[dguercio1984]

The condenser you used is the correct way of doing this however you have your gas and air side mixed up look up shell and tube heat exchangers and power plant condensers by the time your done building it you would probably have another instructable you could post, the direct contact heat exchanger is also correct however there should be a seperate water/oil separator that circulates the exchanger mixture through a series of baffles and returns the water back to the separator the only other thing I think should be addressed is the burner/reactor I wonder if the energy density of this fuel would be enough to make a self sustaining system that could burn some of the reclaimed fuel to power the reactor process?

[msagent]

Is there any explosion or burning issues ?

[DPeeps]

yep you should do this outside away from anything any gas is coming out of the last pipe are probably flammable if you are using a flame to heat the container you could pipe the gas back to the flame and just flare it off to heat the mixture but be careful very careful did I say really very careful your homeowners insurance probably wouldn't cover an explosion in the house

[DamithaN]

Read the article again.

[jayceeluengo]

How many atmospheres there must be to achieve pyrolysis conditions?

[DPeeps]

this system is essentially at atmospheric pressure the key here is keep air from getting into the system oxygen-free