Home Energy Refinery?, With scrap plastic feedstock.

I wonder how difficult it would be to design a small 'home' hydrocarbon refinery, that employs scrap plastics as feedstock, & produces all of a home's energy, motor fuel, & heavy distillate that would be sold like crude oil.
I envision a batch process that would take, say 50-100lbs of scrap plastic shreds or pellets & catalytically crack them into various shorter chain hydrocarbons. The gaseous products could be used to for process heat & possibly for home energy use.
Something where you could pour in a charge, close it up, push a button & come back 5 hours later to find 5 gallons of motor fuel, 5 gallons of heavy distillates, & a hefty charge of heat added to your home energy thermal reservoir. The reservoir that heats, cools, & electrifies your home.

What do you think? Off the grid on garbage?

I reckon the process (if possible) would be done commercially by now. AFAIK most plastics can only be recycled (cost-effectively) into more plastic!

The energy input - electrically or chemically - must exceed that used in the original manufacture hence the lack of such processing now.

Pyrolysis of plastic!

I've been looking into such a thing for a while, It is possible. However,try to avoid black/colored plastics if you can. (Extra carbon left over,and the final product comes out darker.)

There are a few websites,and some Youtube videos on the subject.

I've been wanting to build a small scale 'reactor' and tinker with the idea,but just haven't had the time.
We've got LOTS of plastic bags,and shrink wrap from the battery packaging,we could probably run the business from it. (Giant trash bags of plastic,piled to the rafters.)

There is or was a pilot plant here in Oregon doing this on the commercial scale. It was big news a couple years ago,but I haven't looked into it/heard anything since then.

can you imagine what would happen if *somehow* chlorinated plastics (ie : pvc) got into the mix ?

No because my chemistry knowledge is poor.

How is this cat cracker going to work? Vac. residue is still a lot easier to aspirate than plastic... Aside from that, you need to regenerate the catalyst by burning it off at about 700C, not fun?

Secondly, you'll find it very hard to make petrol without a reformer or alky unit. You don't want an alky, so you'll need a reformer which will require very expensive catalyst and a mechanism for regenerating that...

I think you'll find that oil refining (particularly when you want to make petrol) and from plastic will be very difficult - might not even end up having a net positive energy balance... Not even all oil refineries can make products which meet quality specs either....

OK, total n00b @ chemistry question....

Petrol dissolves PE readily, would not that be able to start the breakdown so the reverse-engineering of the plastic can begin?

Oooh, great idea. Add petrol, then light a fire under it...

I do not think it would be feasable.
coal was used in wwII by germans to manufacture fuel.
but it was not cost effective.

home powerplant can be realised, but i think one would have to go back to the "old school".
there are a few routes i can invision to be feasable.
the most basic would be planting somekindof fast growing tree type that can be processed with ease to chiped fuel, and the good old steam engine will do the rst of the work. more or less this route is allso quite complicated.
As far as i read the forums, Tekwiz most likely can convert a diesel engine block to a crude steam engine, and probably can make a suitable boiler. The other route would be gassification of the chipped wood and running an engine on this gas. (needs a crude engine , something reeeealy crude along the lines of something verry old made for verry crude fuels...)

given enough land oilseed growing has the benefit of yielding diesel fuel "out of the box", but the viscosity of this fuel is higher than regular diesel.
so no high pressure injected newage crap will like it, unless pre-heated.
btter get some older diesel that can burn it.
now, it has the advantage of yielding a side product that has high energy content and 99% that it is allso sellable to anyone who keeps cows. its like crack for them, they go crazy for it.
but the disadvantage is that one needs quite some machinery to work the fields. It has a positive net fuel gain, but the oil seeds simply demand way too mutch from the soil, so one has to ensure to properly replenish it.
That has high costs, even so it would still yield a positive sum.

and the other route would be growing for ethanol.
now.. the plant types that can be grown for ethanol do give more headroom. Many kinds are suitable, some yielding high sugar content, others yielding high hardener contetnt that can be converted to sugar, and then to alcohol. Crop rotation and proper field usage can avoid robbing tha soil without artifical nutrients or extensive use of "manure" (I learned this word here, thank You guys ), but one has to craft machinery that runs on this alcohol to work the fields efficiently.
surely petrol engines can be converted with ease, but its not going to work properly. Alcohol fuel can sustain verry high compression ratio, that is what petrol engines do not have. A diesel engine has more suitable compression ratio, and alcohol can even handle more. (probably a custom cross-head type, compression over 25:1 or even more would be alot more suitable).
So.. these routes are only accessible for those whom have a quite large field to work on.
OR, one can just purchase these agricultural products from a local farmer, make the conversion and pay for the materials with a part of the end product.

The last solution would still require a larger area, but still smaller than agricultural fields. Solar panels, and hydrogen generation from the surplus, and an engine with generator that can use hydrogen fuel.
The costs of setting this up would hit the skys, since producing hydrogen at home is not too efficient, but if the sun is not shining, then the energy stored in the hydrogen is good to have at disposal.
Hydrogen has low energy density, so one would need to store it in tanks, under pressure to save space. Hydrogen gas can be burnt by petrol engines, but then again, the low compression ratio yields only a small efficiency and output power.
Setting up a compressor to compress the hydrogen gas is not easy, most probabyl this solution is hard to manage but in the long run it would be my bet.

REcycling plastic into energy.. well sorely can be done, but as allready mentioned by someone else, many kinds of plastics can only be refined to ..plastic with reasonable efficiency.
Burning plastics as a source of heat is not quite enviroment friendly.
probably a combined solar/wind power input can yield suitable amount of energy, but one still has to think of the conversion losses. I think that the input electricity->hydrogen generation->compression->internal combustion engine + generator chain yields something in the range of no more than 10% or so.

To guestimate, in my home we use roughly 400 KwH of power a month.
so i would need a solar+wind setup to make 4000 Kw of power.
in 30 days. That's 130 ish Kw of power a day. Not at all that impossible, i must say. 20Kw of solar panels could do most of this, and wind power can allso help. Probably if i had a small river, or an other kind of steady stream of water running on my land I might try it with a water turbine, as that can run 24/7 and has reasonably constant output. Probably a 10 Kw turbine could manage it alone.
Actualy water powr could be DIYed with less investment, an old school waterwheel can be verry powerfull.

Let the fun begin!

It's been done -- if you do steam cracking (i.e., shove everything in a boiler at ~300C and ~50atm), even chlorinated plastics break down to HCl (or maybe you'd want a base in there, some lime to absorb the acid, dunno) and hydrocarbons.

Of course, you need an inspected, approved pressure vessel to do this.

Might be able to hack something with extra strength tubing and finely shredded refuse, pumped through heated, pressurized tubing as a slurry, but still...

If you've got some glassware (the lab kind, not.. you know..), you can always try some small experiments. Heat a bunch of crap, dry or in the presence of whatever (solvents won't do you any good as they'll simply evaporate, but maybe you can bubble steam into it or something), and see what condenses. Don't even try putting it in an engine until you've distilled all the fractions out and determined "yeah, this cut here smells about right, and it's pretty flammable, we can try that". Even so, it's a fine line between heptane (0 octane rating) and octane (100 octane rating)!

I don't think there's any catalyst that is particularly selective of chain length. As far as I know, mechanisms are basically free radical destruction. Yeah, you could put hydrogen peroxide in it, tons of radicals there, but it would decompose quickly -- basic promoters include metals notorious for free radicals, like iron (and iron oxide -- rust).

I'm sure there's some method to at least influence molecule size, perhaps depositing catalyst in strategic locations on a nanoscopic mesh (i.e., molecular sieves -- a crystal with pores just the right size for certain molecules to fit), so they "apply pressure" to chains that wander by and prefer to cleave them in useful places. Dunno.

Tim

Johansen was working on some huge pressure tank for fractional distilling of plastics wasn't he? The thing with the dozens of bolts around the outside. Might be reinventing the DF wheel. Whatever happened with that?

question is if it has a nett. positive energy balance or not.
even gold can be made out of any junk material as long as one does not care if it worth it or not.
i do not think it can be done efficiently, but who knows..

There's a lot of that in oil refineries... Sometimes they add pure oxygen to the fire to increase the fun.

Actually, from what I recall from my oil refinery experience (which admittedly was rather brief) what you need to add is lots of hydrogen and lots of heat, and lots of pressure, in the absence of oxygen of course.

Often, a chemical plant that produces an excess of hydrogen as a byproduct, has other chemical plants located nearby that consume the hydrogen in various hydrogenation processes.

Since that's not practical for a home setup, you could probably use natural gas. And to make it cost effective, you need to have a very efficient heat recovery system.


BTW, Tekwiz where have you been hiding lately?

There's a lot of that in oil refineries... Sometimes they add pure oxygen to the fire to increase the fun.

No wonder the earth's axis tilts a fraction of a degree when those refinery guys chuck a ciggie butt where they ought not

How much does it cost to power a home for a day? How much effort would you have to put into this contraption to save yourself the cents to few bucks it would probably cost to from the grid. Wouldn't even a low paying job net greatly more for the energy expended vs money made? It's an interesting idea but it seems like a huge waste of time to me.

Interesting question.

Our 6-mo average hydro came in since the smart meter upgrade and we use 25KWh/day. The average Canadian household uses 31.86.

I have tube amps and we have two high powered desktops running 24/7/365 and we have lights going constantly as our shifts overlap. And I have an electric heater in my porch-shop keeping it very toasty most of the year.

I credit our switch to CFL bulbs for the savings

it got turned into a woodstove.

ok ... so what is that -*ahem*- "item" at the rear of the griddle ?
it kinda looks like a dog ...
naaa ... it couldn't be .

lmao. probably a paper tower