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Q & A: Recycling to conserve energy!

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Most recent answer: 11/01/2011
by recycling glass and metal,does it help to conserve energy?
- Wanting
Tampines North Primary School, SIngapore
Yes! Recycling is a very important way of saving energy! It is also a great way of saving resources. For example, when you throw an aluminum can in the recycling bin, it's taken to the recycling center where it's made into a new can. If you didn't recycle it, they'd have to make a whole new can. To do this, someone has to find somewhere to mine the metals they need. Then they have to mine them, purify them and process them. Then they have to move all that metal from where it was processed to where it will be used. Then they have to make it into a can.

By recycling it, youíre not only saving them from having to use up more metal, but from having to do all that extra work. Every time they have to move the metal from one place to another (like from where itís mined to where itís used), they have to use gasoline and other forms of energy for the transportation. It also takes energy to mine it and to purify it, etc. So by recycling, you can save a lot of energy!


For aluminum, the purification requires a huge amount of electrical power, so this is the key stage at which recycling it saves energy. Mike W.

(published on 10/22/2007)

Follow-Up #1: energy savings of recycling

Is it also energy/resource efficient to recycle plastic and paper? (can you remember to answer for both materials, thanks)
- Jacob (age 19)
Salt Lake City, Utah, United States
We don't have any special knowledge of this. Wikipedia says there's a range of estimates for how much energy is saved by paper recycling, but all estimates agree there are savings. )

Plastic usually isn't really recycled but rather made into some secondary plastic product. For example, bottles can be made into carpets.  The amount of energy savings depends a lot on what the alternate materials would have been for the secondary products. In some cases the savings are large. ()

Mike W.

(published on 11/01/2011)

Follow-Up #2: Recycling Glass

I have a question about the recycling answer you gave earlier. You only answered for aluminum recycling. I am wondering if that holds true for glass recycling as well since it is much easier to produce glass than it is to produce aluminum (assuming we start from scratch).
- Anonymous
University of Illinois, Champaign, Il
Even for glass it takes less energy to recycle it than to make it. Remember, it takes more than just melting sand to make glass. Like for metals, there is a lot of background work involved. Only very fine sand is used to make glass, and there are people who make their profession out of finding that sand. So in order to make glass, we have to provide the energy to feed and take care of everything for those people. Then we have to collect the sand. This also takes people and machines, and the energy to support them.
Then the sand has to be transported to wherever it's going to be used. (Remember - sand is usually found near the coast.) It takes a lot of energy to support the people and vehicles that will move the sand to where it will be used. With recycled glass, you still need to support people to do the recycling, but not to go out and find the recyclables. You don't have to transport the glass as far as sand.

There are so many different little things that use energy that go into everything we do that it's easy to forget about a lot of them. For example, it takes energy to transport the trees that will be made into paper that will be printed into money that will be distributed to banks so that it can go to pay the person who writes the paychecks for all the employees of the company that makes the lunches for the company that digs up the sand. ;)

Even at the simplest level, though, it takes less energy (less heat) to melt glass back into liquid glass than it does to melt sand into liquid glass.

Hope this answers your question.


(published on 10/22/2007)

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