US-12617127-B2 - Plastic recycling method for processing plastic waste

Abstract

A plastic recycling method for processing plastic waste, including providing a plastic waste mixture stream having, on the one hand, a variable proportion of 2D material and a variable proportion of 3D material and, on the other hand, an inhomogeneous density distribution, the proportions varying over time. Washing both proportions of the plastic waste mixture stream together. Shredding both proportions of the plastic waste mixture stream together while supplying a cleaning fluid. Density-based separation of the plastic waste mixture stream into at least two fractions, wherein the separation is performed as a function of a predeterminable density separation cut; and for at least one of the separated fractions: separating the fraction of 2D material and the fraction of 3D material from each other.

Inventors

• Andreas Stolzenberg
• Markus Börger

Assignees

• GRANNEX GMBH & CO. KG

Dates

Publication Date

20260505

Application Date

20220429

Claims (20)

1. 1 . A plastic recycling method for processing plastic waste, comprising: Providing a plastic waste mixture stream having a variable proportion of 2D material and a variable proportion of 3D material in an inhomogeneous density distribution, wherein the 3D portion comprises voluminous plastic waste and the 2D portion comprises sheet plastic waste or film plastic waste, the proportions varying over time; Joint washing of both portions of the plastic waste mixture stream; Joint shredding of both portions of the plastic waste mixture stream while supplying a cleaning fluid; and thereafter: Density-based separation of the plastic waste mixture stream into at least two fractions, wherein the separation is performed in response to a predeterminable density separation cut; for at least one of the density separated fractions, separating the fraction of 2D material and the fraction of 3D material from each other.
2. 2 . The plastic recycling method of claim 1 , further comprising: detecting the proportion of 2D material and/or the proportion of 3D material in the plastic waste mixture stream; regulating a feed parameter of the plastic waste mixture stream depending on the detected proportion of 2D and/or 3D material.
3. 3 . The plastic recycling method according to claim 1 , wherein separating the portion of 2D material and the portion of 3D material from each other is performed after separating the plastic waste mixture stream into two fractions.
4. 4 . The plastic recycling method according to claim 1 , wherein separating the waste plastic mixture stream into two fractions is performed after shredding the waste plastic mixture stream.
5. 5 . The plastic recycling method according to claim 1 , wherein the washing of the plastic waste mixture stream occurs prior to the shredding of the plastic waste mixture stream.
6. 6 . The plastic recycling method according to claim 1 , wherein a further joint washing operation of both portions of the plastic waste mixture stream occurs after the plastic waste mixture stream is shredded.
7. 7 . The plastic recycling method according to claim 6 , wherein the washing and the further washing of the plastic waste mixture stream are each performed in a friction washer.
8. 8 . The plastic recycling method according to claim 1 , wherein prior to separating the portion of 2D material and the portion of 3D material from each other, dewatering of the plastic waste mixture stream is performed.
9. 9 . The plastic recycling method of claim 8 , wherein the dewatering comprises mechanical and/or thermal dewatering.
10. 10 . The plastic recycling method according to claim 1 , wherein the density-based separation of the plastic waste mixture stream is repeated a plurality of times to enrich a desired material fraction.
11. 11 . The plastic recycling method according to claim 1 , wherein the plastic waste mixture stream is fed to a centrifugal separator, for separation into two fractions.
12. 12 . The plastic recycling method according to claim 1 , wherein the predeterminable density cut for separating the plastic waste mixture stream is adjustable between 1 and 1.05 kg/dm 3 .
13. 13 . The plastic recycling method of claim 11 , wherein separating into two fractions comprises enriching a light fraction in at least a first hydrocyclone and enriching a heavy fraction in at least a second hydrocyclone.
14. 14 . The plastic recycling method of claim 1 , wherein the 3D portion comprises hollow plastic waste.
15. 15 . The plastic recycling method according to claim 1 , wherein the washing is carried out by means of water, and wherein water is used as cleaning medium in the shredding of the plastic waste mixture stream, the water being free of cleaning agents and/or flocculants.
16. 16 . The plastic recycling method according to claim 1 , wherein the separation of the portion of 2D material and the portion of 3D material is performed by wind sifting.
17. 17 . The plastic recycling method according to claim 1 , comprising the following steps prior to washing the plastic waste mixture stream: Pre-crushing of the plastic waste mixture stream; Separation of heavy material and impurities from the pre-crushed plastic waste mixture stream, wherein the heavy material has a higher density than the plastic waste mixture stream.
18. 18 . The plastic recycling method according to claim 17 , wherein the pre-crushing of the plastic waste mixture stream takes place in the dry state of the plastic waste mixture stream.
19. 19 . The plastic recycling method of claim 17 , wherein the separation of the heavy material is performed by means of a heavy material trap, wherein the heavy material trap comprises a float-sink separation over which the heavy material is separated.
20. 20 . The plastic recycling method of claim 17 , wherein separating the heavy material is further preceded by separating biogenic fractions.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/DE2022/100325, filed on Apr. 29, 2022. The entire disclosure of the above application is incorporated herein by reference. BACKGROUND This section provides background information related to the present disclosure which is not necessarily prior art. Technical Field The invention is based on a plastic recycling method for processing plastic waste, which essentially comprises the steps of washing, shredding, and separating a plastic stream. Discussion Rising volumes of plastic waste pose huge challenges for our society in the coming years. In 2019, around 5.35 million tons of post-consumer plastic waste was generated in Germany. Of this, only 1.33 million tons was sent for material recycling in processing plants within Germany. From this, in turn, only 1.03 million tons of output was ultimately generated in a quality suitable for reuse in the plastics processing industry. This corresponds to a quota of just over 19%. The truth about Germany's performance in plastics recycling and the use of recyclates is correspondingly sobering. As of today, Germany does not have the necessary recycling infrastructure to economically and technically process the quantities of plastic waste generated here into high-quality recyclates. Many processing plants today are not state of the art, are outdated and have very weak economic foundations. Increasing plastic waste volumes, stricter national and international legislation on approval procedures and on increasing recycling rates and the use of recyclates, as well as waste import & export restrictions, pose huge challenges for EU member states and especially plastics recyclers in the coming years. Investments in reprocessing capacities and especially the development of new reprocessing processes to solve the described challenges and problems are urgently needed. One of the biggest challenges for plastics recyclers are highly contaminated plastic waste mixtures. With existing recycling processes & plants, these fractions can currently only be recycled to a very limited extent. Therefore, a large part of this waste currently finds its way into thermal recycling. In addition, a large proportion of the recyclates produced do not allow stable plastics processing due to qualitative deficits and therefore rarely replace virgin material in technically sophisticated plastic products on a sustainable basis. Today's situation calls for new approaches to processing and the creation of additional capacities in order to meet the requirements of the Packaging Act and KrWG, among others, which are already in force today, to sustainably increase material quotas and to provide the plastics processing industry with sufficient quantities of plastic recyclates of a particularly high and consistent quality as a substitute for primary plastics in the future. The development of economically viable concepts for the mechanical processing of heavily contaminated and mixed plastic waste volumes, which have so far been predominantly thermally recycled, is critical. New and modern processing technology holds great potential to meet recycling quotas and, among other things, to avoid levies on plastic waste mixtures that have not yet been recycled in Germany and to reduce a further economic and ecological burden caused by plastic waste volumes that are not recycled. Often, mixed plastics are collected but are only sent for recycling after passing through complex dry-mechanical separation steps such as ballistic separators or NIR sorters. However, because films, bags and trays can only be poorly cleaned and separated from other types of plastics in these existing processes and plants, large parts of them are not sent for reprocessing but are lost for recycling. These sorting residues that are not recycled are therefore recovered for energy and the thermal energy they contain is used to provide electricity and district heating. A process for the separation and recovery of plastics is known from DE 10 2013 213 478 A1. In this process, the desired types of plastic are separated from a resulting plastic mixture at the beginning of the process, followed by cleaning and drying, size separation, color sorting, separation of the desired types of plastic by grade, color sorting of the plastic batches, and granulation and production of regranulates. The disclosed process has the disadvantage that a pre-separation of certain types of plastics is already carried out at the beginning, and thus only a low recycling quota can be achieved, since the separated plastics are for the most part not recycled but sent for thermal utilization. SUMMARY This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. It is therefore one aspect of the present invention to improve a plastics recycling process for the t