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Comment by quaintdev | Hacker News Reader

So what is wrong with this? I am assuming it only takes soft plastic but still why we don't see widespread use of it.

I'm guessing the answer is, "Because you can already burn the plastic directly." Presumably burning this oil would have the same levels of pollution as burning the plastic in the first place, but also takes extra energy to produce.

Other than if you have a Mr Fusion you can’t run a car off of solid plastics. But, I assume some additional steps are required to make it usable. The site doesn’t detail the possible uses of the the oil, but generally liquids and solids can be used in different situations. The oil could also be used as lubricant rather than an energy source.

I don't know if most households have enough use for lubricants to be able to consume a quantity equivalent to 80% of the volume of plastics they're disposing of. My door hinges and bike-chains can only be so smooth. Even if it was converting it into usable motor-oil (which I doubt it is) I don't think I could consume that much.

I suppose if it's usable for a kerosine type of lamp maybe, but is it pure enough to not present respiratory issues? And why would I need a kerosine lamp?

Yeah I don’t think it’s the next Nespresso and they probably need to detail the use cases better. But I can see this useful in a machinist shop that might have a lot of waste plastic from packing materials etc.

Airplanes run off kerosene, so that's a sizeable market if this fuel is good enough

No chance the FAA lets people use homemade recycled plastic oil in their turbojet engines. Jet turbines are very tolerant of different fuels, but this is a bridge too far.

Many people still have ICE cars, you left that intentionally out?

I mentioned motor oil

No way I'm trusting oil made from random household waste plastic as the primary lubricant in my car engine. What are the lubricating properties? What are the breakdown characteristics? High temperature resilience? Presumably it would vary by batch. You are just begging for a seized engine.

An electric car can, in my area they burn garbage for electricity:

https://pinellas.gov/waste-to-energy-facility/

Flammable lubes are a big no no

They don’t detail much about the properties of the oil produced

Also, plastics can contain all sorts of nasty toxic surprises. Better to burn it at a centralized location with proper filtering and treatment than having little batches or mystery oil of varying quality and toxicity.

> Better to burn it at a centralized location with proper filtering and treatment than having little batches or mystery oil of varying quality and toxicity.

If we can assure that the output meets a standard should we burn it, then certainly we should be able to assure the output meets a standard should we refine/convert it.

And the conversion of plastic into oil will have cost much more energy, producing the same pollution in the end.

But at least we save some landfill space. Also micro-plastics contamination is everywhere.

In the USA, landfill space concerns are based on a hoax. Landfill space is a function of landfill development, and there’s no shortage of spaces to create landfills.

I am not talking about running out of space in general. I am talking about taking a hill covered with trees or farms, and turning it into a hill of garbage. Surely you can see why I would prefer a natural hill?

If you can burn it, there is no point in burring it. We're still taking a lot of stuff from underground and burn it for energy, why not burn the stuff we already have above ground?

Landfills amortize the carbon emissions. Keeping the plastic's carbon temporarily sequestered in a landfill puts it somewhere other than the atmosphere. Eventually we'll have to do something with all that carbon, but we're better off burying it until we get a better handle on emissions in general.

You can still burry the soot after you burned the plastic.

Most of the carbon is going to end up as CO2 in the air, though.

You don't need to burn it in an open field ...

You can used a closed system so that the waste is actually all captured. Or you can have a more continuous system that'll capture/scrub the output.

Unless you capture it, as Amsterdam has been doing.

CO2 capture is a scam, perpetrated by the petroleum industry to make people think it's okay to burn more fossil fuels.

You would be right, IF we were to not take out any other fossil fuel to burn. But to bury the plastic now it just means we will dig for an equivalent quantity of coal, oil or gas to burn. We will burn some stuff regardless, we might as well burn what we already have, instead of burying it and digging for new stuff.

Since this consumes electricity, the energy need could be filled by running the converter at peak hours for renewable energy, so effectively soak up excess energy to recover oil that's already out of the ground. Which would be a net win in terms of energy, possibly even financially depending on the investment costs for that device. Assuming it even holds up to the promises.

All these processes best done in centralized plants with quality controls, not in bench processors.

It is more efficient to burn it, generate electricity and charge a EV battery with it, than it is to convert it to fuel (consumes energy) and burn it in an internal combustion engine (very low efficiency due to small scale).

It's much easier to purify the burning waste products than raw trash. It is much less varied.

I don’t believe plastic burning is a widespread energy source.

Japan and I believe Singapore burn most of their plastic in incinerators to generate electricity. Coincidentally they are also among the highest plastic waste producers per capita.

Korea, Taiwan, and Switzerland are similar.

It happens in waste-to-energy power plants (a.k.a garbage power plants). They can be a great way to get rid of waste but they require a lot of filtering of the exhaust to be safe. Adequate filtering is universal in some countries (like Sweden). In the USA, waste-to-energy plants frequently have inadequate filtering, which can make them dirtier than coal plants.

Do you know if they have to reach a certain temperature ? I would think so because I assumme garbage produces a lot of fumes and gases that would better off burned for energy rather that ending in the air. On the other end I wonder what kind of temperature you can get with a dumpster fire

Incinerators in Japan must be above 800C to avoid generating toxic materials like dioxins. https://www.env.go.jp/content/900453393.pdf

> In the USA, waste-to-energy plants frequently have inadequate filtering, which can make them dirtier than coal plants.

Source? With EPA being so rigid about diesel cars it would doubt that. Unless the whole regulation was about keeping german car manufacturers in cheque...

In my city there is an incineration plant which produces about 94 GWh of electricity a year, covering 11% of city's needs.

I imagine it's easier to purify the oil and burn the oil with high efficiency, than to burn solid garbage and filter the flue gas.

Presumably the noxious byproducts are released during the oil recycling process? It would explain where all of that missing mass went. But if this is the case you'll still need to filter the gas so there is little benefit.

I think the oil it produced would be worth about £0.25 (GBP) (400ml assuming the price is the same as Brent crude and ignoring the cost of the input plastic or the machine itself etc). But the power to run it (3kWh) would cost about £1 (1GBP) at current rates at least here in the UK.

I might be wrong, I'm not sure whether the oil produced is equivalent to Brent crude (I picked it at random) or more valuable or less...

Still might make sense when solar/wind is at peak to make it as a longer time storage? While still getting rid of plastic waste.

But of what use is that mystery oil? All current petroluem products are highly quality controlled, both for lubrication and use in engines. You didn't get rid of the plastic, you converted it into a liquid which you must now dispose of safely. The only upside I see is that the plastic won't litter and turn into micro plastics in the ocean, but since it's already collected, then burn in a central plant ASAP IMHO.

You could probably use it in a diesel engine. People filter used frying oil from restaurants and run their diesels on that.

Yes, you absolutely can, especially in an old diesel engine, they can run on all kinds of oil. But the engine might not fare well, depending on the properties of the oil, and the exhaust might contain "interesting" stuff like dioxins, depending on what was in the mystery plastic to begin with.

I would say if this could be done by some utility company, that company could have diesel engines to generate power from that oil which could have filters and all that stuff.

I assume it still could be profitable because people who want to get rid of plastic waste would still have to pay. Getting excess power from grid is also something one would get paid for. Then turning on generators when grid needs power to get paid when there is a power shortage.

But as I write this out I imagine that it would require massive amounts of investments for setting up such operation and getting all kind of permits or environmental studies and god knows what. Let alone getting deals with electric companies - so I think that would be something that some electric company would have to set up. They would most likely have most know-how for such setup.

Meanwhile, the power company in this city burns plastic (and all kinds of waste) in their co-generation plant and gets electricity and residential heating.

If you’re going to burn it for electricity in a stationary location, skip the middle man and burn the waste itself.

Also old diesel engines are bad for air quality and efficiency

There's an argument to be made here for refurbing the best of the container ship engines after the ship hulls reach end of life.

The higher end engines are three storey high multistaged diesel engines with filters, scrubbers and some of the highest bunker oil -> power efficiencies on the planet.

They're ideal for generating baseload power and worth the rejuvenation effort.

Most (80% was the number I saw) large bunker-oil engines with scrubbers installed simply dump the removed sulphides into the sea as wastewater instead of venting it into the atmosphere. Not to mention the colossal amounts of carbon-related pollutants.

Solvable problems via a retrofit to be sure, but overall I'd rather than the HFO's are simply not burned at all.

Last I checked oil was the primary ingredient in making plastic. This could be a way to recycle plastic that is not recyclable by normal means.

plastic is a byproduct of the petroleum production process.

Much of the feedstock for plastic is from natural gas, not from oil. Fracked gas in particular has a lot of ethane, which is converted to ethylene and then to polyethylene. The rise of fracked gas in the US caused PE production to move here.

> But of what use is that mystery oil?

You can probably power the next few runs of the machine with it.

The key may be economically transporting the waste plastic as feedstock. Guess it may be much more expensive. Even assuming 5 cents/ kwh of solar this makes economic sense as storage system otherwise. I presume in the future we have autonomous robots that clean the cities of plastic and feed it to such machines which run on surplus renewable energy

You still have people paying for their waste disposal, so I would assume transport cost should be covered by that.

Also makes sense in Japan (and Korea, and maybe other places I don't know about), where the populace is very mindful not just of making sure garbage ends up in a can, but as well separating it based on the type of garbage.

Contrast with the US, where people decide to save a few bucks a month by dumping their garbage bags along the side of the road, or tossing garbage out the window of their car.

When running on spare hydro, wind or solar power which cannot be accumulated or returned to grid, it can have some uses.

I'm not sure the economics works on something like that. Once you buy all the equipment, employees, and commercial buildings, it simply isn't going to be profitable to only run your factory 10% of the time (How often does solar power go wasted? Not actually sure).

Maybe it would work if this was only one step in a larger processes. When energy is free, use it to make a ton of this crude oil and then process the crude with less energy intensive methods when electricity is expensive.

If this is a thermal process, then intermittent cheap energy can be stored in thermal masses (firebrick, for example) much more cheaply than in batteries, and the heat used later. That way that later stage can be kept operating more continuously.

More worth than crude. Crude also needs processing. The output from this bench processor is probably somewhere around the red fraction here:

https://petroleumservicecompany.com/blog/oil-barrel-42-gallo...

Thanks!

The very small scale ensures it isn't economical.

If thermal decomposition of plastic is to be worthwhile, it would be on the scale of oil refineries (which it would likely resemble.)

It might be worthwhile to separate plastics now, not for conversion now, but to stockpile for later processing by this or other means. Just put the stuff in plastics-only landfills designed to ease later mining. Fixed carbon will be more valuable after fossil fuel use ends.

I would imagine that its not economically viable at scale. First, it might be too energy-intensive for the value of the end product, and second, the plastic you can get is still the plastic that you're able to separate from trash, which it might be better to just recycle it normally. These are just peanut-gallery guesses though, I don't know for sure.

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