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Recycling is a economic-cost vs environmental-value optimization problem. The university I studied at also has a department that analyzes renewable energies an

by dbrgn 7y ago

Recycling is a economic-cost vs environmental-value optimization problem. The university I studied at also has a department that analyzes renewable energies and recycling. They developed a system that does this cost-vs-value-analysis for recycling. In the end, you get a number of environmental points for every dollar you invest into recycling. The core idea is that we have a certain budget to improve our environment. If a dollar invested in plastic recycling is 20 times less efficient than a dollar invested in glass recycling, then we should stop recycling plastic. The results (for Switzerland): Glass and aluminum recycling works great. Battery recycling is OK, but because today's batteries contain way less toxic chemicals (like Cadmium) than they did in the 80s, it's largely an artifact from the past. They consider battery recycling good enough to keep, but wouldn't start recycling them if the infrastructure wouldn't exist right now. Mixed plastic recycling is being hyped right now. There are companies that offer subsidized plastic bags where you can throw in all kinds of plastic. According to the study, the environmental value of recycling such mixed plastics in Switzerland is really low and should not be done, we are basically wasting our money which would be better spent on other projects that have higher value. Their summary was basically that instead of recycling plastic and burning fuel in combustion engines, we should convert oil to plastic products and then - once they have reached the end of the lifecycle - burn those in modern incineration plants. The energy gained from that can then be used to heat buildings and to power electrical cars. This way, the energy is re-used, first in a product, then in mobility. Of course that only works if you have modern, clean incineration plants. If you burn the plastics on a pile, then the environmental value of plastic recycling skyrockets.

dsfyu404ed 7y ago
>. Their summary was basically that instead of recycling plastic and burning fuel in combustion engines, we should convert oil to plastic products and then - once they have reached the end of the lifecycle - burn those in modern incineration plants. The energy gained from that can then be used to heat buildings and to power electrical cars. This way, the energy is re-used, first in a product, then in mobility. Note that this solution is so obvious what every high school chemistry student proposes as soon as they learn that plastics are made from oil and have similiar molecular structure. We just don't do it because I don't know why.
- zdragnar 7y ago
  Because 100% of the oil doesn't go to fuel or plastic. There are different chemicals distilled and they have different purposes, such as making asphalt, lanolin, naptha, paraffin wax, kerosene / jet fuel, and other goodies. Maybe 40-50% of a barrel of oil at most becomes gasoline and diesel, 4% becomes plastic. Add on top of that the difficulty in getting people to recycle plastic instead of throwing it out or littering, and you have a very inefficient supply chain for your energy production.
  - AnthonyMouse 7y ago
    Those are two independent problems. On the one hand, how do we generate electricity. On the other hand, what do we do with plastic garbage. "Burn it to generate electricity" solves the second one entirely by solving a small fraction of the first one. That is not a flaw, it just means that we still need solar panels and nuclear reactors to make up the difference. It still gets rid of the plastic garbage -- and the fact that it's a small proportion of electricity production is a feature, because burning plastic gets it out of the landfill, but it's not exactly carbon neutral. Doing it at smaller scale, especially if it replaces that amount of power generation from coal, is more feasible than burning plastic (i.e. oil) to generate all of our electricity. > There are different chemicals distilled and they have different purposes, such as making asphalt, lanolin, naptha, paraffin wax, kerosene / jet fuel, and other goodies. Maybe 40-50% of a barrel of oil at most becomes gasoline and diesel, 4% becomes plastic. The distillation process can actually be tuned within a fairly broad range to produce different output products with varying degrees of efficiency. It's also possible to make bioplastics from biomass, though hardly anybody does that because it's more expensive.
- wool_gather 7y ago
  > this solution is so obvious what every high school chemistry student proposes... At the risk of sounding flippant, "For every complex problem, there is a solution that is simple, obvious, and wrong". There's no guarantees that the energy arithmetic works out here. Even without the logistics of collection and transport, is cleanly burning plastic waste efficient enough to be worthwhile (cf. why it's almost unheard of to use wood to generate power)?

by dbrgn 7y ago

dsfyu404ed 7y ago

>. Their summary was basically that instead of recycling plastic and burning fuel in combustion engines, we should convert oil to plastic products and then - once they have reached the end of the lifecycle - burn those in modern incineration plants. The energy gained from that can then be used to heat buildings and to power electrical cars. This way, the energy is re-used, first in a product, then in mobility. Note that this solution is so obvious what every high school chemistry student proposes as soon as they learn that plastics are made from oil and have similiar molecular structure. We just don't do it because I don't know why.

zdragnar 7y ago
Because 100% of the oil doesn't go to fuel or plastic. There are different chemicals distilled and they have different purposes, such as making asphalt, lanolin, naptha, paraffin wax, kerosene / jet fuel, and other goodies. Maybe 40-50% of a barrel of oil at most becomes gasoline and diesel, 4% becomes plastic. Add on top of that the difficulty in getting people to recycle plastic instead of throwing it out or littering, and you have a very inefficient supply chain for your energy production.
- AnthonyMouse 7y ago
  Those are two independent problems. On the one hand, how do we generate electricity. On the other hand, what do we do with plastic garbage. "Burn it to generate electricity" solves the second one entirely by solving a small fraction of the first one. That is not a flaw, it just means that we still need solar panels and nuclear reactors to make up the difference. It still gets rid of the plastic garbage -- and the fact that it's a small proportion of electricity production is a feature, because burning plastic gets it out of the landfill, but it's not exactly carbon neutral. Doing it at smaller scale, especially if it replaces that amount of power generation from coal, is more feasible than burning plastic (i.e. oil) to generate all of our electricity. > There are different chemicals distilled and they have different purposes, such as making asphalt, lanolin, naptha, paraffin wax, kerosene / jet fuel, and other goodies. Maybe 40-50% of a barrel of oil at most becomes gasoline and diesel, 4% becomes plastic. The distillation process can actually be tuned within a fairly broad range to produce different output products with varying degrees of efficiency. It's also possible to make bioplastics from biomass, though hardly anybody does that because it's more expensive.
wool_gather 7y ago
> this solution is so obvious what every high school chemistry student proposes... At the risk of sounding flippant, "For every complex problem, there is a solution that is simple, obvious, and wrong". There's no guarantees that the energy arithmetic works out here. Even without the logistics of collection and transport, is cleanly burning plastic waste efficient enough to be worthwhile (cf. why it's almost unheard of to use wood to generate power)?