The biggest problem recycle faces is not technology (this is not unexpected), it is supply chain. Getting the tons of waste from people's houses to a large recycling facility is an expensive and cumbersome challenge. Creating the concept that the old mattress has a "value" is a wrong idea, it has a cost, much like with batteries and tires these mattresses need to have a recycle fee attached to the price of sale, the central fund used then to pay for the logistics.
A quick thought exercise, how much would you have to be paid to take your mattress to your local "large recycle facility"... the value of the 20kg of recycled materials maybe after processing (that includes the processing cost) is $20 -$40...If it was much more, mattresses would be very expensive.
It is something we need to do, we just need a good business model...think of a $1,000 mattress needing a $100 recycle fee in the sale price. It could work
100% the logistics are the big challenge which I didn't even touch on. It's a challenge now for plastics and we at least some infrastructure to try and handle getting recyclables to MRFs.
You raise a great point on the fee. I think if we use a "deposit" model it could work. We would just need that deposit to be $100-200 and have it built into the sale price so that when it comes time to get a new mattress the owner can just in theory "transfer" that to a new mattress.
I remember attending some seminars about Niaga when I was at DSM and thinking similar things.
The logistics are *hard*. A foam mattress typically absorbs a substantial amount of water during use and by the end of its life may weigh up to 40% *more* than when new. I feel like in large metro areas there need to be receiving facilities that dramatically simplify logistics by dehydrating mattresses, chopping them up, and vacuum sealing them in a transportation friendly manner. That also simplifies pickup of recycling feedstock.
Roman is absolutely right that a mattress must be considered a feedstock for an end product rather than a valuable asset. That kind of focus allows one to innovate realistic path to value generation rather than wishful thinking and green washing/marketing proposals.
The other question I have is the energy and %recovery state of the art in reversing a polyurethane reaction. It is *much* easier to recycle rPET because 1) it's not cross-linked, 2) polyesters can undergo simple hydrolysis while polyurethanes form a much more stable bond.
I've seen "green" feedstocks offered on the market at 2x the price with 1/4 the supply chain certainty (which is already fraught). As much as I want to make my products as green as possible, doing so to the maximum possible extent is both fiscally and strategically irresponsible. You cannot create a sustainable product with an unsustainable commitment to your customers on quality and supply. Perhaps the polyol feedstocks can be blended into commodity feedstocks at quality and served as a product that's not distinguished, if they can get their marketeers and publicity folks to be ok with that.
Raj, totally agree on the logistics piece. I think overall it should be up to the system houses to also develop the infrastructure to deal with the incoming raw materials because I don't think they should be farming this out to MRFs.
If they can build the plant to do the chemical recycling they should also be able to build out the receiving facilities. You should in theory be able to have the receiving facility relatively close to your recovery plant operations too.
Doing gylcolysis of PET with MEG is nice because you get the benefit of running a simple esterification reaction in excess glycol which also tends to act as a solvent at relatively high temperatures and if you run it long enough you essentially are back to starting monomers like BHET or Bis(2-hydroxyethyl) terephthalate and you just apply vacuum and strip the excess MEG off.
The urethane bond is relatively weak compared to other thermosetting resins. I mean it starts to unzip around 200 C and I did see some some sketchy patent literature around using primary aliphatic amines to unzip the urethanes at high temperatures. For example if you don't dry a urethane resin prior to extrusion it reacts with the water and you get a bunch of bubbles in your extruded product (seen this first hand).
But yeah, I think ultimately it comes back to how much does it cost to depolymerize a mattress and is the juice worth the squeeze?
That's a fair point - and forming ureas with excess water is always an annoyance. I respect and agree with your point on relative efficacy of urethane thermosets compared to say, epoxies and amides, but I think there is an efficacy gulch between hydrolytic degradation of a polymer melt and the unzipping of a thermosetting urethane.
The biggest problem recycle faces is not technology (this is not unexpected), it is supply chain. Getting the tons of waste from people's houses to a large recycling facility is an expensive and cumbersome challenge. Creating the concept that the old mattress has a "value" is a wrong idea, it has a cost, much like with batteries and tires these mattresses need to have a recycle fee attached to the price of sale, the central fund used then to pay for the logistics.
A quick thought exercise, how much would you have to be paid to take your mattress to your local "large recycle facility"... the value of the 20kg of recycled materials maybe after processing (that includes the processing cost) is $20 -$40...If it was much more, mattresses would be very expensive.
It is something we need to do, we just need a good business model...think of a $1,000 mattress needing a $100 recycle fee in the sale price. It could work
100% the logistics are the big challenge which I didn't even touch on. It's a challenge now for plastics and we at least some infrastructure to try and handle getting recyclables to MRFs.
You raise a great point on the fee. I think if we use a "deposit" model it could work. We would just need that deposit to be $100-200 and have it built into the sale price so that when it comes time to get a new mattress the owner can just in theory "transfer" that to a new mattress.
I remember attending some seminars about Niaga when I was at DSM and thinking similar things.
The logistics are *hard*. A foam mattress typically absorbs a substantial amount of water during use and by the end of its life may weigh up to 40% *more* than when new. I feel like in large metro areas there need to be receiving facilities that dramatically simplify logistics by dehydrating mattresses, chopping them up, and vacuum sealing them in a transportation friendly manner. That also simplifies pickup of recycling feedstock.
Roman is absolutely right that a mattress must be considered a feedstock for an end product rather than a valuable asset. That kind of focus allows one to innovate realistic path to value generation rather than wishful thinking and green washing/marketing proposals.
The other question I have is the energy and %recovery state of the art in reversing a polyurethane reaction. It is *much* easier to recycle rPET because 1) it's not cross-linked, 2) polyesters can undergo simple hydrolysis while polyurethanes form a much more stable bond.
I've seen "green" feedstocks offered on the market at 2x the price with 1/4 the supply chain certainty (which is already fraught). As much as I want to make my products as green as possible, doing so to the maximum possible extent is both fiscally and strategically irresponsible. You cannot create a sustainable product with an unsustainable commitment to your customers on quality and supply. Perhaps the polyol feedstocks can be blended into commodity feedstocks at quality and served as a product that's not distinguished, if they can get their marketeers and publicity folks to be ok with that.
Raj, totally agree on the logistics piece. I think overall it should be up to the system houses to also develop the infrastructure to deal with the incoming raw materials because I don't think they should be farming this out to MRFs.
If they can build the plant to do the chemical recycling they should also be able to build out the receiving facilities. You should in theory be able to have the receiving facility relatively close to your recovery plant operations too.
Doing gylcolysis of PET with MEG is nice because you get the benefit of running a simple esterification reaction in excess glycol which also tends to act as a solvent at relatively high temperatures and if you run it long enough you essentially are back to starting monomers like BHET or Bis(2-hydroxyethyl) terephthalate and you just apply vacuum and strip the excess MEG off.
The urethane bond is relatively weak compared to other thermosetting resins. I mean it starts to unzip around 200 C and I did see some some sketchy patent literature around using primary aliphatic amines to unzip the urethanes at high temperatures. For example if you don't dry a urethane resin prior to extrusion it reacts with the water and you get a bunch of bubbles in your extruded product (seen this first hand).
But yeah, I think ultimately it comes back to how much does it cost to depolymerize a mattress and is the juice worth the squeeze?
Thanks for the thoughtful comment!
That's a fair point - and forming ureas with excess water is always an annoyance. I respect and agree with your point on relative efficacy of urethane thermosets compared to say, epoxies and amides, but I think there is an efficacy gulch between hydrolytic degradation of a polymer melt and the unzipping of a thermosetting urethane.