Knee jerk reaction is not feasible, but get passed past that and bit and what are the options?
So waste plastic non sorted likely unknown plastic scrap, mixed with dry organic matter that will crumble and burn, mixed with waste pulp and wood
powder.
What oxidizer is possible to mix into a pellet around 12mm to 20mm, forced air is ok but burn temperature needs to be around 3200C, boiler would be
tungsten based. Is this possible?
I am aware in principle seems too dangerous, but surely there is a way around the problems, end goal a Combined Heat And Power system.
System needs to be small enough to power no more than 5 - 12 houses tops. So huge furnaces out the question. My reaction was maybe Chlorates but can
you make a Chlorate mix safe with organics?
Press for pellets is wet system and upto 40 tons of pressure, no simple cant be done without reasons please, i dont /cant say impossible without
knowing for sure there isnt a way around the problems.
Temperature needs to be very high to meet air standards and get almost complete combustion, the figure of 3200C was taken from a now defunct system
designed for waste plastic burning.
But there is a scheme looking into options to deal with large amounts unsorted waste, not sure how much money the grants are.
Grants for pilot schemes are based on practical pilot schemes.
So if this is a KFO fair enough, but would prefer to explore all options before doing the KFO to it.Bert - 3-3-2018 at 06:43
Please fully spell out any terms you use at least once before going to acronyms.
But I'm afraid I can't help with
KFONEMO-Chemistry - 3-3-2018 at 08:31
Yes sorry CHAPS is really common here especially when your head is on Combined Heat And Power systems. My bad sorry..
KFO is kindly foof offwg48 - 3-3-2018 at 10:19
Why do you need such a high burn temperature of 3200C. Tungsten will readily oxidise at that temperature.
I am guessing that 1,200C would be sufficient to oxidise most if not all organics.
Adding a relatively expensive oxidiser compared to the waste will probably make it uneconomical and if its chlorate that will increase corrosion and
pollution.
Guessing again even crematoriums these days have pollution controls, which tend to be more economical with larger scale than a 12 house system and
burning waste plastic will almost certainly involve a lot of pollution mitigation no matter how small the system is. unionised - 3-3-2018 at 10:57
Very few things burn as hot as 3200C https://en.wikipedia.org/wiki/Adiabatic_flame_temperature#Co...
Rubbish won't.
Adding an oxidiser is as likely to reduce the flame temperature as to raise it.
You can, in principle use pure oxygen, or even ozone to get things hotter but it would be terribly expensive.
"According to the European Waste Incineration Directive, incineration plants must be designed to ensure that the flue gases reach a temperature of at
least 850 °C (1,560 °F) for 2 seconds in order to ensure proper breakdown of toxic organic substances. "
What i have is a paper document, thats the temp it states. What i dont know is why its so hot, or rather why it WAS so hot... The place is no longer
open but was the one place where plastics were used as fuel.
Jump forward 4 years and now there is a large collection via some machine that clears beaches. it picks up seaweed and plastic all in a tangle. Zero
waste Scotland policy says they cant bury it, last year they composted most the organic stuff and then lifted the plastic out.
But for some reason that isnt stated it was considered a fail. next week There is a APSE seminar and conference for local authorities in kenilworth
England. The guy in charge of energy for our council has asked me to go with him, the reason has nothing to do with plastics, but something else i
came up with last year.
I got passed the folder in the post today, it dosnt say much of use but he wanted to do know if i had ANY ideas i could put forward as its the single
worst thing our local council gets wrong with energy and waste management.
I havnt got a clue about it! so its likely i will stand up and so say, i had hoped i was going to be asked about the bio methane stuff.
But apparently no one gives a chit about that in Scotland because we have wind mills. And plastic...
Its highlu likely your correct, the document has several things wrong in it anyway, but its all i got to go on. Had we not of been snowed in for
nearly a week i might have got the folder earlier.
The bit i am going to is on the 8th. Dosnt give me much time to ask questions... NEMO-Chemistry - 3-3-2018 at 13:30
Just a thought but these are generators and heat providers in a single boiler. I am not convinced the temperature is all about the rules, it could be
a number picked from the air by the council chamber. Like i said i submitted last year a new biomethane concept.
Personally without trying to sound a ass i think its a really good idea and pretty unique, so in all honesty burning plastic is a long way off what i
thought i was getting into. The docs contain details of two old and closed plants, one was long thanet and the other isnt named.
So we need alot of hot water and we need a turbine powered by steam i guess. The fuel is basically waste that has to be made into pellets. If we cant
get the temp in the paperwork, can it be made to burn inside the regs and do the above?
I know its cheeky to even ask, and in all fairness its why i said i am ok with a KFO. I am willing to stand up when its my turn and simply say i dont
know! But my nature means i wont do that if i can find an option. I am not asking for a solution i am looking for starting ideas.Vomaturge - 3-3-2018 at 13:59
I have to agree with wg48 about the tungsten. Even below its melting point, it oxidizes really quick. Using such a high temperature may have few
benefits anyway. I'd expect a lower temperature, maybe 1500C to decompose and oxidize almost all of the organic compounds. The problem with adding
oxidizers to the fuel is that it takes way to much energy to form say, chlorates. As far as I know, industry makes those using a horribly inefficient
electrolytic process. I think you need somewhere between 20 and 70 kj of electricity to make a gram of sodium chlorate. No way will that be feasible
for waste disposal.
Now, if the waste you need to destroy really needs 3200C, there are probably ways of attaining that. It looks like gaseous oxygen can be separated
from air using as little as 720 joules per gram of oxygen: http://www.ieaghg.org/docs/General_Docs/Reports/2007-14.pdf
I have also wondered what would happen if you preheated the fuel and/or air in a heat exchanger, using the exhaust gases. It seems that you could
create combustion much hotter than the adiabatic flame temperature. To withstand the heat, you could maybe make the walls of the combustion chamber
out of aluminum oxide or something else porous, then blow the air/oxygen through them. With enough pores, close enough to each other, you could
prevent convective heating: http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefi...
Now, this also could stop conduction, by keeping the burning waste from touching the alumina (think of a big flaming air hockey table). for the same
reason, the surfaces could theoretically be kept clean enough to reflect radiant heat. If it works, and you can concentrate oxygen efficiently on a
small scale, you could get the waste really hot without the walls of the chamber exceeding their melting point.
Now, if all that works, here's what I suggest you do: a) use a bit more oxygen then is needed and let a hair of nitrogen in too. Recover the ensuing
NOx and make nitrates. b) use the power you generate for the aforementioned electrolytic chlorate process. Or c) concentrate some extra oxygen,
ideally as a liquid. Now take a few choice pieces of trash, and combine them with the oxidizer to make explosives or rocket fuel. Yay! Space travel
via rubbish!
I'm not trying to mock you, or your idea. I think extremely high temperature incineration is unneeded for most plastics, but it can be achieved when
needed. It might work better on a large scale, though. Pure elemental oxygen has been considered for power generation, if only to produce a CO2/H2O
exhaust free of nitrogen, which could be more easily captured for carbon sequestration. I like the idea of using waste as fuel, and a few
modifications to your scheme would allow it not only to be potentially feasible, but also destroy materials you normally shouldn't burn, like PVC and
maybe even PCBs.NEMO-Chemistry - 3-3-2018 at 14:09
OOO hang on, i dont want to make chlorates, i was thinking of using them as the oxidizer.... All i need to make is alot of heat (hot water) and steam
for a turbine.
I am wondering if a slip in typing has made the 3,200 because nothing i can find on the site that was at long gannet suggest it was near that temp,
but it was used to burn all clinical waste and plastics for electric generation. So seeing as most agree 3200 is way off i am tempted to call this a
typo in the doc i got, OR its F and not C...
I know the power station used forced air for a clean burn, but i doubt they used oxygen etc. I got the gig because i signed up for the young
Councillor scheme, my local parish council runs a scheme for young people who might want to go into local politics.
So i shadow a couple of Councillors and get invited to things i know nothing about, i dont say much (so this is out of the closet stuff) because
obviously its a major source of piss taking with my peers. aga - 3-3-2018 at 14:12
What i have is a paper document, thats the temp it states.
Please post the Title/Author/Date of the paper, or a link to it, or a photo of it or a scanned image.
It's pointless asking about stuff when only you know what you're talking about.
Nexasium Success ! (just for the fun)
aga - 3-3-2018 at 14:32
Today were hentrated tremendermous quarters of tibilim sectors in order to achieve a portion of Nexasium.
Fortunately the reference i found behind a statue in Rome says that it should be soluble in pergastis solution, so i tried it.
Amazingly the congelate pergastis re-combobulated the tibilium, although it foamed a lot.
At this point the experiment was halted by means of the Knugerast method, involving a full pint of pure perclast - yes, it is dangerous but it was
necessary to prevent a gremolation of the xantitude.
After much refining, the fine crystals of the crudantus were separated by means of a wooden spoon, then washed, and treated with zubantarum lotion to
remove any traces of negativity.
Once set, the crystals were chanted, then the Heat of Horus was applied for 6 hours.
Finally they sublimed into the Purest Nexasium i have ever seen !
This must be the easiest route to Nexasium ever !
No Cypherbone, no Coltsfoot, no Dragon Hide, or tooth - just common materials ! Vomaturge - 3-3-2018 at 14:49
You don't have to make any chlorates. My point there was just that solid oxidizers are better suited to explosives and rockets. You will not be able
to get enough solid oxidizers for cheap enough to burn waste that way. I do like your idea of the composite pulp-plastic pellets. I think that part is
great, but they need to be burned in air, or maybe concentrated elemental oxygen. When I said pure oxygen has been considered for power plants, I was
talking about the paper on oxygen separation. They proposed using pure oxygen to make exhaust without any nitrogen, so that it would not interfere
with capturing carbon dioxide. You are right, most power plants just use forced air.
For a small-ish facility, like the one you are proposing, the oxygen might need to come from a separate existing plant. More likely, you don't even
need pure oxygen. Burn the dry plastic pellets in air, in a properly designed furnace, and that should be good enough. The main issue is getting
enough air in to oxidize everything, so that no soot is produced. Wether or not the paper you read really meant 3200 C, you probably could do a good
job with half that. When proposing a combined heat and power incinerator burning plastic composite pellets, you might be able to get away with not
mentioning the temperature at all. Now, if they say "But... but you can't just burn plastic, that's toxic!" You can explain that you will be burning
it with such high heat, with so much air (not solid oxidizer)that nothing toxic will be released. Explain that burning it in a fireplace or open pit
is sooo much dirtier than a well regulated furnace, possibly with an exhaust scrubber. After they've accepted the idea, you can figure out the
details, get it to work at 3200 C, 3200 F, 1032 F, or whatever, so long as it's clean and efficient.
Speaking of poor oxygenation and low temperature burning, what about a gasifier, running an internal combustion electric generator? I know that's off
topic, but it might be an easier build for a small scale plant like this? Your idea with a turbine seems workable too, but generators in the <100
kw range are sometimes just gas powered. NEMO-Chemistry - 3-3-2018 at 15:45
No the CHAP system is a fixed thing, you are paid X amount for each unit of electric and heat you make, so the kind of thing you can use or design is
fairly fixed. the paper isnt a science published paper. its a council paper, it isnt something i can post online.
Its not like the kind of document your thinking of aga, its more a bundle of crap from the last time they talked about it in chamber. the seaweed side
I wonder if you take the plastic and seaweed mix and dump it into a methane reactor, then filter the plastic out and treat that separate.
I dont know much about the specific boilers used for CHAPS, but they have a hopper that takes pellets, the stuff i got gives the various size pellets
that fit.
Now panic has settled a bit, i might start the other end, see what the rules on exhaust are. I guess that dictates the temperature, that and I do know
you have to have a low ratio of ash to the amount you burn. I cant find the figure yet, but its similar to the forced air boilers they use in homes,
these burn wooden/paper pellets.
I didnt think i was going to this one, but with the snow etc we havnt had post from Dumfries for a few days, we are clear where I am, but where the
council office is its been hit hard.
I doubt anyone will build anything, but you never know. I am surprised they got the beach sweeper! So just maybe they will actually try and do
something about the plastic around the coast here. I could be lazy and simply say we dont have firm plans, but in all honesty this kind of thing is
something i am really into and would like to see used.
