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Question: Are cans much better for the environment? I've long preferred cans to bottles for things like soda (although I almost never drink it anymore), sparkli

Question: Are cans much better for the environment? I've long preferred cans to bottles for things like soda (although I almost never drink it anymore), sparkling water, etc. They've always seemed to get and stay colder, although that may not be the case. I feel a little bit better about my preference when picking a canned La Croix over a bottled Arrowhead at work, but I realize now that I don't really have any idea about the environmental impact of cans v. bottles.

michelledepeil 8y ago
I believe cans are more easily recyclable, in part because they're so easy to seperate from other trash (using a big magnet).
- calebegg 8y ago
  Most beverage cans are made from aluminum, which is not magnetic.
  - ohithereyou 8y ago
    Aluminum is not ferromagnetic, but if you get it near a 3 Tesla magnet, trust me, you'll know.
  - verytrivial 8y ago
    The material really just need to be conductive to feel the effect of A/C fields due to eddy currents as a Random Purveyor of such a device explains: http://www.walkermagnet.com/separation-eddy-current-separators.htm http://www.walkermagnet.com/separation-eddy-current-separato...
    - rexaliquid 8y ago
      Relevant SMBC: https://www.smbc-comics.com/comic/proof https://www.smbc-comics.com/comic/proof
    - cypherpunks01 8y ago
      Youtube "Magnapower Eddy Current Separator - Material Separation Tests": https://www.youtube.com/watch?v=QQ6ZC9MKNAw https://www.youtube.com/watch?v=QQ6ZC9MKNAw
- newnewpdro 8y ago
  I assume the main difference is the high temperatures used to melt metals like aluminum back down to ingots will either burn off all the contaminants or bring their remains to the surface to be easily removed like skimming dross. Plastics recycling is a much more delicate process, requiring all sorts of washing steps and finely controlled relatively low temperatures.
- akiselev 8y ago
  Aluminum isn't ferromagnetic so magnets don't work with it and stripping the graphics off a soda can alone requires just as much energy and nasty chemicals as other recycled materials. That's before you even smelt anything, which usually requires a forge that spends insane amounts of energy just to keep it from shutting down and needing an even more expensive cold start. It's not that recycling aluminum is easier than other materials, it's that making aluminum from raw bauxite is like the above process times ten. The chemicals are even more dangerous, the process management (environmental protection, regulatory compliance, etc) more expensive, and it requires even more energy. As a result, between 1/3 to 2/3 of all aluminum sold in the US comes from recycled materials because of economic reasons.
  - munk-a 8y ago
    Your mention of advertising... I'd be really happy if we could start cutting down the insane effort we're putting into dyeing things and just relegate flashy marketing to the waste bin of history. The same with form advertising (clam shells and the like) where additional material is added just to make a product look more attractive.
    - lozenge 8y ago
      The clam shells make shoplifting difficult, and you need to get the barcode onto the can at a minimum, at which point what difference does the rest of the label make?
  - kretor 8y ago
    https://en.wikipedia.org/wiki/Eddy_current_separator https://en.wikipedia.org/wiki/Eddy_current_separator
  - michelledepeil 8y ago
    I was likely wrong wrt my argumentation. However, Eddy currents (TIL) make seperation _fairly_ easy if you have the right equipment, and comment https://news.ycombinator.com/item?id=18702317 https://news.ycombinator.com/item?id=18702317 seems to think "cleaning" and smelting are easier than in the plastic bottle case.
rootusrootus 8y ago
Aluminum cans are very easy to recycle. About 2/3 worldwide are recycled, which is the highest of any material. They probably just seem like they get colder because of the higher conductivity of the aluminum. The downside is that they don't stay cold nearly as long as a plastic bottle. The condensation that forms on the outside of a cold can expends a lot of energy into the liquid.
extrapickles 8y ago
Cans are more straightforward to recycle, and have a small positive residual value without subsidies. Bottles do not. It’s also surprisingly easy and cheap to make your own sparkling water. If you get a counter top unit, people make CO2 adapters for them that let you use standard 5/20 lb cylinders rather than the way overpriced ones the original vendor has. A standard 20lbs cylinder will last 22x as long as the cylinder the units come with, and don’t cost much more to exchange. A welding supply shop typically has food grade CO2 for roughly $1-3/lb as they also supply all the nearby restaurants. If you want flavors without sugar, bitters used for cocktails make for a easy way to flavor the water you just carbonated.

michelledepeil 8y ago

I believe cans are more easily recyclable, in part because they're so easy to seperate from other trash (using a big magnet).

calebegg 8y ago
Most beverage cans are made from aluminum, which is not magnetic.
- ohithereyou 8y ago
  Aluminum is not ferromagnetic, but if you get it near a 3 Tesla magnet, trust me, you'll know.
- verytrivial 8y ago
  The material really just need to be conductive to feel the effect of A/C fields due to eddy currents as a Random Purveyor of such a device explains: http://www.walkermagnet.com/separation-eddy-current-separators.htm http://www.walkermagnet.com/separation-eddy-current-separato...
  - rexaliquid 8y ago
    Relevant SMBC: https://www.smbc-comics.com/comic/proof https://www.smbc-comics.com/comic/proof
  - cypherpunks01 8y ago
    Youtube "Magnapower Eddy Current Separator - Material Separation Tests": https://www.youtube.com/watch?v=QQ6ZC9MKNAw https://www.youtube.com/watch?v=QQ6ZC9MKNAw
newnewpdro 8y ago
I assume the main difference is the high temperatures used to melt metals like aluminum back down to ingots will either burn off all the contaminants or bring their remains to the surface to be easily removed like skimming dross. Plastics recycling is a much more delicate process, requiring all sorts of washing steps and finely controlled relatively low temperatures.
akiselev 8y ago
Aluminum isn't ferromagnetic so magnets don't work with it and stripping the graphics off a soda can alone requires just as much energy and nasty chemicals as other recycled materials. That's before you even smelt anything, which usually requires a forge that spends insane amounts of energy just to keep it from shutting down and needing an even more expensive cold start. It's not that recycling aluminum is easier than other materials, it's that making aluminum from raw bauxite is like the above process times ten. The chemicals are even more dangerous, the process management (environmental protection, regulatory compliance, etc) more expensive, and it requires even more energy. As a result, between 1/3 to 2/3 of all aluminum sold in the US comes from recycled materials because of economic reasons.
- munk-a 8y ago
  Your mention of advertising... I'd be really happy if we could start cutting down the insane effort we're putting into dyeing things and just relegate flashy marketing to the waste bin of history. The same with form advertising (clam shells and the like) where additional material is added just to make a product look more attractive.
  - lozenge 8y ago
    The clam shells make shoplifting difficult, and you need to get the barcode onto the can at a minimum, at which point what difference does the rest of the label make?
- kretor 8y ago
  https://en.wikipedia.org/wiki/Eddy_current_separator https://en.wikipedia.org/wiki/Eddy_current_separator
- michelledepeil 8y ago
  I was likely wrong wrt my argumentation. However, Eddy currents (TIL) make seperation _fairly_ easy if you have the right equipment, and comment https://news.ycombinator.com/item?id=18702317 https://news.ycombinator.com/item?id=18702317 seems to think "cleaning" and smelting are easier than in the plastic bottle case.

rootusrootus 8y ago

Aluminum cans are very easy to recycle. About 2/3 worldwide are recycled, which is the highest of any material. They probably just seem like they get colder because of the higher conductivity of the aluminum. The downside is that they don't stay cold nearly as long as a plastic bottle. The condensation that forms on the outside of a cold can expends a lot of energy into the liquid.

extrapickles 8y ago

Cans are more straightforward to recycle, and have a small positive residual value without subsidies. Bottles do not. It’s also surprisingly easy and cheap to make your own sparkling water. If you get a counter top unit, people make CO2 adapters for them that let you use standard 5/20 lb cylinders rather than the way overpriced ones the original vendor has. A standard 20lbs cylinder will last 22x as long as the cylinder the units come with, and don’t cost much more to exchange. A welding supply shop typically has food grade CO2 for roughly $1-3/lb as they also supply all the nearby restaurants. If you want flavors without sugar, bitters used for cocktails make for a easy way to flavor the water you just carbonated.