Sunday, June 6, 2010

Tour of a Recyclables Sorting Facility

Yesterday I took a tour of a recyclables sorting facility and I learned a ton of great information. Two things that I took away are:
1) We use, and throw away, a lot of stuff and
2) An hour tour of a sorting facility doesn't make you an expert.

Another important lesson was that every sorting facility (and I am guessing processing plant) has different equipment, and therefore different rules about what can and cannot be recycled and also how you need to prepare the materials before you bring it to the curb. What I learned yesterday doesn't necessarily apply to your sorting facility and doesn't even apply to mine. Knowing how to recycle in your neighborhood is something that is very important to find out. Please find out what the rules are for your town and follow them. The list of items that aren't recyclable is there for a reason. These items get thrown out anyway and if they are not caught in time can cause a lot of damage to the machines that sort the materials.

Even though I am not and expert I would like to take this post (and maybe a few future posts) to show you what I have learned and to dispel some myths about recycling. Feel free to ask more questions or comment about anything in the comments below.

First off, what is a sorting facility? A sorting facility doesn't actually recycle anything. They take a stream of materials that are all (hopefully) recyclable and sort them in to piles of like materials, bail them and send them off for mills and plants to recycle.

The facility we visited was capable of sorting zero-sort materials. Zero-sort is a term that basically means that the consumer doesn't need to separate the paper from the plastic or cans and bottles. They put it all in one bin and the sorting plant divides it up. The process to do this was both fascinating and complicated.

For the most part it is an automated process but there are also 30 people on the line manually sorting materials, mostly for quality control. Their jobs are to pull out materials that are not recyclable, find stuff that is recyclable but can't run through the machine because it will damage the machine, such as plastic bags, which are recyclable but too light for the machine to process properly and will also get tangled in the machine and cause a lot of damage. Finally the grab stuff that was not sorted correctly and either run it through the machine again or sort it by hand.

After quality control the whole process is, at the least, 95% accurate and they strive for 97%. The mills that they send the final product to are able to work with 5% contamination but anything above that is no good.

The facility we toured runs 5 days a week in 2 shifts. They have the ability to run on weekends and a third shift at night but right now they don't receive enough materials to sort. Sometimes the 2 shift goes home early because they run out of materials to sort. This is because estimates put the amount of stuff we throw out that is recyclable at 60%. WOW! That is horrible.

The mechanical process involved to sort the materials is amazing. When you see the piles of materials in the dock it is hard to believe that it is possible to sort and looks like it would take forever but the plant is currently sorting 700 tons of materials a day. That's around 15,000 tons a month and they would be able to do much more if we sorted the recyclables from the trash better at home.

I am not going to go in to details of each station along the way because I fear that I will not be totally accurate and I would hate to put details up that are not correct. I will tell you that the glass bottles all get broken. The small pieces of glass fall through a hole in a screen and are separated from the other trash in this fashion. This answers one question of what happens to the metal lids, they either; fall in with the glass and are separated by the glass plant, or they are too big to fit through the hole and wind up in the metal pile.

Plastic containers are sorted in the one section that I found to be the craziest. The materials all pass under a beam of light. The light passes through the plastic containers and is bent by the plastic. Depending on the type of plastic the light is bent differently. The light then bounces off of the conveyer belt and back up into a camera. The camera detects how the light was bent and sends a signal to a computer that tells an air jet to fire, in the correct location at exactly the right time. The air jet pushes the plastic container up in the air, over a hole where all the other materials go, and into a bin. This is done first for the number 1 plastic and then for the number 2. I believe the numbers 3 through 7 are all kept together but I am not 100% sure about that. Either way this is the process that sorts the plastics from the other trash and from each other. And it all happens very quickly.

Lids that are left on plastics may not be the same materials as the bottles. Again this is sorted up by the next plant by melting the plastic. The labels and mismatched lids are going to melt or burn at a different temperature. So a plastic bottle can be fine while the lid melts and then they have a bottle and some melted plastic which can be easily separated.

Metals that are attracted to magnets are simply separated by a huge magnet. This removes any steel and tin plated steel cans.

Aluminum cans are removed using the same force that keeps you from pushing the north side of a magnet against another north side of a magnet. They use this force, reverse magnetic polarity, to propel the cans off of the conveyor belt into a bin. She didn't go into detail of how this works exactly but I did find an article that explains a little bit more if you are interested. (

Metal that is too large for the machine to handle is brought to a scrap yard and recycled there. Since the plastic bags can't run through the machines they are collected and made into little plastic pellets for future use. At this point the pellets are approved to be burned for fuel and they are working on the process of liquefaction so they could be used to fuel the trucks that pick up the materials and deliver them once they are sorted. But we aren't there yet.

The visit was very educational but just a small piece of the overall puzzle. This plant simply sorts the materials and sends them to other facilities to use. The melting down and other processing is all done at the other plants so it was impossible to get he answers to all the questions that I have. For example, it is only necessary, as far as the sorting facility is concerned, to rinse the jars and containers of food enough to help reduce rodent problems in the plant. But the needs of the tin plant or plastic plant may be totally different. I am guessing that they need the materials to rinse more than the sorting facility but I can't say how much.

According to the tour guide the amount of energy saved by recycling one tin can (after transportation and other energy costs are accounted for) saves enough energy to power a TV for three hours. So unless you are using enough energy to power a TV for 3 hours to rinse your cans I would say it is still well worth it to rinse and recycle a tin can. No other examples of how much energy it takes to recycle something where given but I may research this further in the future.

Materials that are not recyclable are thrown out and wind up in the same place they would have if you threw them out in the first place.

Another important detail is that recyclables placed inside a plastic bag or trash bag will be removed and end up in the land fill. This is because they cannot tell what is inside the bag without opening it and they do not want to open plastic bags that often contain trash. It is best to NOT throw your recyclables out in a plastic bag. Just leave them in the bin on the curb with no bag.

The materials once separated are worth different amount. Styrofoam is too light to weigh enough to make any money off of and needs to be melted down before it is bailed which is also difficult to do so a lot of facilities do not accept it which is why it may not be recyclable in your town. Other materials vary in price according to how useful they are. Glass is hard to get rid of and after factoring the cost of trucking this facility actually pays to have their glass taken away. Tin on the other hand is very valuable, right now. The prices of everything change like the stock market and even experience crashes. In 1999 and 2008 the prices of materials went down so much that the plants the sorting facility didn't have contracts with wouldn't take any more materials. This company rented a warehouse and stored the materials until the market went back up. I doubt that all companies do this but it is nice to know that they are not just dumping the glass because they lose money on it and that they take the extra effort to make sure things are recycled as much as they possibly can.

I hope to learn more about the overall process of recycling and will share everything I learn with you. Thanks to Gisela for inviting me on this tour, this should be a featured attraction on her website for sure. I hope she enjoyed it as much as I did and I hope you enjoyed hearing about it.

1 comment:

  1. Thanks for coming along! It was very interesting and since we visited, I feel like I have more recycling than I have trash so the statistics that 60% of what we throw out could be recycled is probably true.

    Let´s not be lazy and through out stuff just because it is easier than rinsing it out and keeping it for recycling day.

    I vote for prettier 'blue bins' that doesn't stick out like a sore thumb in the hall way.

    (and yes, I should probably put it on