4 ms·

Stupid question, but why not to burn plastics directly generating heat and electricity? With proper filtering it shouldn’t be very poisonous.

by lnsru 4y ago

Loic 4y ago
With proper filtering, the problem here is that in a typical refinery, you do not filter the kind of compounds released by these new plastic handling processes. You filter out mercaptan, H2S, CO2 using post processing gas treatment like amine cycles. This is because you have a very clear process line, which has not changed in the past 100 years or so. You basically separate from the raw oil what is already good from what needs more processing. What needs more processing is simply "cut in small pieces and possibly recombined" to get more out of your feed. The new processes try to "keep" more good molecules from the "plastic feed", this leaves more room for loss of good molecules for the chemical use downstream but bad for the environment if not filtered out. Burning everything to make electricity/heat is what you have everywhere in Europe (at least) and this cuts "everything in small pieces" and as such you can use normal gas treatment down the line. The gas treatment is expensive but effective. Update: I am surprised the EPA is so lax, the US is way stricter than the EU for normal emissions from refining.
WirelessGigabit 4y ago
It already exists: https://en.wikipedia.org/wiki/Plasma_gasification https://en.wikipedia.org/wiki/Plasma_gasification
- deleted 4y ago
  [deleted]
jillesvangurp 4y ago
Incinerating waste is already common and when done properly does not result in a lot of toxic emissions. Technology for this has been in use for decades. When done poorly, the result is a lot of toxic fumes. Which is perhaps the issue this article is hinting at. Of course, generating fuels from plastic that you create from oil is still transferring fossil deposited carbon straight into our atmosphere. Euphemistically labeling that as a bio fuel does not change that and is more than a bit disingenuous/misleading. And probably intentionally so by those advocating this. There's nothing green or climate friendly about this. Dumping it a landfill is literally better for the environment because at least then the carbon goes back into the ground. Of course you do get some local pollution with that. So, it's not a perfect strategy. Incineration with carbon capture might be feasible but is probably going to be expensive. Of course getting rid of a lot of single use plastics is better still. The best carbon capture strategy is simply leaving it in the ground and not messing around with it.
- mjevans 4y ago
  I'm not sold on people reusing the 'durable' bags a sufficient number of times to even outperform their plastic counterparts. I suspect the durable bags will become damaged or worn out to the point where they're replaced before even break even in the majority of cases. I would prefer that the old, cheap, paper bags (without the handles) were a free at checkout option. If plastic bags are offered the laws should be changed to require that they are sold __at cost__ not __for profit__. Currently this is just a huge money grab that every business is doing where I live (WA state); including force bundling unwanted bags for online orders. I would like the option of natural wax coated paper spoons that can stand up to a yogurt cup or bowl or two of cereal. That takes care of the 80% use case of grab and go breakfast at places. Leave my dang straws alone, or at least have that tiny bit of material made out of a plastic that some bacteria can breakdown but which is otherwise an OK plastic. Convenience store cups and pre-packaged foods would also be good things to look at using such a plastic on.
  - actionfromafar 4y ago
    Plastic bags do not genererate a lot of carbon emissions, but the do cause a lot of problems in waterways. Even in places where there is almost no littering, sure enough, there are plastic bags or there remnants just about everywhere if you look for them. In other places it's just a shit-show, which caused them to be banned.
  - tmerc 4y ago
    Nothing is stopping you from buying and reusing paper bags until they wear out. They cost like $0.05.
    - mjevans 4y ago
      Handled ones are sold for $0.40 / bag (offhand, I purchased like 10 of them when this insanity started), and I've thus far reused most of the bags in the set 4x, one 5x, and one had a handle failure early in life. I'm convinced that paper, even used once and tossed into a landfill, is better for the environment, and that the effort involved in reusing the bags is not worth creating a more durable bag that can't instead be reused as packing paper, a bin liner, or some other task before it joins the long term molecular reprocessing cycle. If the waste stream company didn't charge extra for a kitchen scraps bin (which is co-mingled with yard waste, that I refuse to create) I'd gladly properly dispose of used bags in that container instead, along with food scraps.
random_savv 4y ago
Even with proper filtering it seems to cause some problems, e.g.: https://www.stadt-zuerich.ch/ted/de/index/departement/medien/medienmitteilungen/2023/januar/310131a.html https://www.stadt-zuerich.ch/ted/de/index/departement/medien... "In 2022, the canton of Zurich examined the surroundings of waste incineration plants (WIP) for dioxins and published the results in November. No massive or large-scale contamination like in Lausanne was found in the canton of Zurich. However, the random sample from the Josefwiese was within the range of the legal test value of 20 nanograms of toxicity equivalent per kilogram (ng TEQ/kg)."

Stupid question, but why not to burn plastics directly generating heat and electricity? With proper filtering it shouldn’t be very poisonous.

by lnsru 4y ago

Stupid question, but why not to burn plastics directly generating heat and electricity? With proper filtering it shouldn’t be very poisonous.

Loic 4y ago

With proper filtering, the problem here is that in a typical refinery, you do not filter the kind of compounds released by these new plastic handling processes. You filter out mercaptan, H2S, CO2 using post processing gas treatment like amine cycles. This is because you have a very clear process line, which has not changed in the past 100 years or so. You basically separate from the raw oil what is already good from what needs more processing. What needs more processing is simply "cut in small pieces and possibly recombined" to get more out of your feed. The new processes try to "keep" more good molecules from the "plastic feed", this leaves more room for loss of good molecules for the chemical use downstream but bad for the environment if not filtered out. Burning everything to make electricity/heat is what you have everywhere in Europe (at least) and this cuts "everything in small pieces" and as such you can use normal gas treatment down the line. The gas treatment is expensive but effective. Update: I am surprised the EPA is so lax, the US is way stricter than the EU for normal emissions from refining.

WirelessGigabit 4y ago

It already exists: https://en.wikipedia.org/wiki/Plasma_gasification https://en.wikipedia.org/wiki/Plasma_gasification

deleted 4y ago
[deleted]

jillesvangurp 4y ago

Incinerating waste is already common and when done properly does not result in a lot of toxic emissions. Technology for this has been in use for decades. When done poorly, the result is a lot of toxic fumes. Which is perhaps the issue this article is hinting at. Of course, generating fuels from plastic that you create from oil is still transferring fossil deposited carbon straight into our atmosphere. Euphemistically labeling that as a bio fuel does not change that and is more than a bit disingenuous/misleading. And probably intentionally so by those advocating this. There's nothing green or climate friendly about this. Dumping it a landfill is literally better for the environment because at least then the carbon goes back into the ground. Of course you do get some local pollution with that. So, it's not a perfect strategy. Incineration with carbon capture might be feasible but is probably going to be expensive. Of course getting rid of a lot of single use plastics is better still. The best carbon capture strategy is simply leaving it in the ground and not messing around with it.

mjevans 4y ago
I'm not sold on people reusing the 'durable' bags a sufficient number of times to even outperform their plastic counterparts. I suspect the durable bags will become damaged or worn out to the point where they're replaced before even break even in the majority of cases. I would prefer that the old, cheap, paper bags (without the handles) were a free at checkout option. If plastic bags are offered the laws should be changed to require that they are sold __at cost__ not __for profit__. Currently this is just a huge money grab that every business is doing where I live (WA state); including force bundling unwanted bags for online orders. I would like the option of natural wax coated paper spoons that can stand up to a yogurt cup or bowl or two of cereal. That takes care of the 80% use case of grab and go breakfast at places. Leave my dang straws alone, or at least have that tiny bit of material made out of a plastic that some bacteria can breakdown but which is otherwise an OK plastic. Convenience store cups and pre-packaged foods would also be good things to look at using such a plastic on.
- actionfromafar 4y ago
  Plastic bags do not genererate a lot of carbon emissions, but the do cause a lot of problems in waterways. Even in places where there is almost no littering, sure enough, there are plastic bags or there remnants just about everywhere if you look for them. In other places it's just a shit-show, which caused them to be banned.
- tmerc 4y ago
  Nothing is stopping you from buying and reusing paper bags until they wear out. They cost like $0.05.
  - mjevans 4y ago
    Handled ones are sold for $0.40 / bag (offhand, I purchased like 10 of them when this insanity started), and I've thus far reused most of the bags in the set 4x, one 5x, and one had a handle failure early in life. I'm convinced that paper, even used once and tossed into a landfill, is better for the environment, and that the effort involved in reusing the bags is not worth creating a more durable bag that can't instead be reused as packing paper, a bin liner, or some other task before it joins the long term molecular reprocessing cycle. If the waste stream company didn't charge extra for a kitchen scraps bin (which is co-mingled with yard waste, that I refuse to create) I'd gladly properly dispose of used bags in that container instead, along with food scraps.

random_savv 4y ago

Even with proper filtering it seems to cause some problems, e.g.: https://www.stadt-zuerich.ch/ted/de/index/departement/medien/medienmitteilungen/2023/januar/310131a.html https://www.stadt-zuerich.ch/ted/de/index/departement/medien... "In 2022, the canton of Zurich examined the surroundings of waste incineration plants (WIP) for dioxins and published the results in November. No massive or large-scale contamination like in Lausanne was found in the canton of Zurich. However, the random sample from the Josefwiese was within the range of the legal test value of 20 nanograms of toxicity equivalent per kilogram (ng TEQ/kg)."