SPEX: Recycle Plastic
by Dissolution

OBBOTEC-SPEX has a unique solution for recycling plastic (PE & PP). From a plastic-rich waste stream of polyethylene (PE) and/or polypropylene (PP), PE and PP plastic is selectively extracted by dissolution. This removes the additives and contaminants such as color, odor, plasticizers, and flame retardants. SPEX cleans the plastic (PE & PP) back to near-virgin quality. Afterwards, it can be reused within new, high-standard applications, such as plastic packaging. The yield of this recycling process is almost 100% because only the contaminants and other plastics are being removed.

Do you want insight into the external analysis? Download the CE Delft report here

Towards High-Quality

About half of all plastic used is polyethylene (LDPE, HDPE) or polypropylene (PP). At the end of its lifecycle, this plastic ends up in the environment or with a waste processor, where it is recycled, incinerated, or dumped. Producing conventional plastics is an energy-intensive process and incinerating plastics has a negative impact on the environment, using fossil fuels and generating CO2 emissions.
Besides, current recycling methods often do not produce the desired results. Mechanical recycling, for example, often does not meet the required plastic quality. Additionally, chemical recycling technologies that run via a (naphtha) cracker are low in terms of mass and energy efficiency.

Below you will find our mini lecture about the advantages and disadvantages of the various recycling techniques.


From Plastic to Plastic

Currently, there are several chemical recycling techniques to make the plastics supply chain circular. There are parties who use pyrolysis (heating) to recycle plastic into oil or naphtha, which is cracked to syngas. Other parties return plastic to monomers through depolymerization, like with PET.
Depending on how far back you go in the chain, it takes a lot of energy to break plastics down and rebuild it thereafter. Chemical recycling will therefore have a limited positive impact on the environment if you go too far back in the chain. The big difference compared to SPEX’s dissolution is that all these parties break down plastic into its original building blocks and therefore go further back in the chain.


Chemical recycling has a great impact on the yield. In the production of petroleum/naphtha to plastic, it takes about three kilograms to produce one kilogram of plastic.

When you recycle this kilogram of plastic and go back to the beginning of the chain to make naphtha (pyrolysis), you have an efficiency of about 50%. That leaves 500 grams of naphtha. When you turn these 500 grams of naphtha, you can make about 170 grams of plastic. So, if you recycle one kilogram of plastic, you can have a circular chain, but at a very low yield of about 170 grams of plastic, which is less than 20%. This means you lose more than 800 grams of plastic that must be replenished with fossil fuels to generate one kilogram again. This reduces the positive environmental impact substantially. With the dissolution technology of SPEX, the yield of a waste stream of one kilogram of plastic is almost 100% (PE & PP) plastic. This is because no plastic molecules are lost, only the contaminants are removed.

Clean Plastic of
Near-Virgin Quality

In mechanical recycling, the waste streams are separated by machine. Nowadays it is possible to achieve this at a very advanced level. But the big difference with the dissolution solution from SPEX is the quality of the plastic.
In mechanical recycling, the plastic is externally cleaned but internally there will always be contamination left behind. Additives such as colorants, fragrances, plasticizers, or flame retardants are not removed. Mechanical recycling does not offer 100% separation between the plastic types and does not offer 100% separation by color. The contaminants remain behind in the plastic and are processed into recycled plastic. Therefore, the origin of mechanically-recycled plastic must be 100% guaranteed before it can be used for food packaging. With the dissolution technology from SPEX, both external and internal substances including additives are almost completely removed. The dissolution process results in a high-quality, clean, 'near virgin' plastic which can be used in a wide range of applications.

Our Decentralized
HydroCat Model

SPEX is developed with small-scale production in mind, and for very good reasons:

1. Small-scale units with a capacity of up to approximately 10 kilotons per year
2. Units are located at a waste processor, recycler, or converter for a specific (PE & PP) plastic stream
3. Model offers logistical advantages, as the supply chain is short and transport distances can be limited

SPEX partners

Do you want more information about the recycling techniques of OBBOTEC?
Please contact us