Page 172 - CW E-Magazine (29-10-2024)

Special Report Special Report

The importance of mass balance in chemical recycling polymer portion of the output to maxi- Table 1: Visual Mass Balance Representation with 20 recycled units and 80
virgin units
mize value. Hence, the chemical recycling
industry favors mass balance that errs on
hile chemical recycling capa- Mass balance is particularly chal- JOSHUA DILL the side of free allocation.
cities are showing signs of lenging with thermal depolymerization/ Analyst, Plastics Recycling - ICIS
Wgrowth globally, legislation conversion recycling, even when com- There is pushback on this style of
surrounding chemical recycling is still pared to other types of chemical recyc- processes to chemically break down plas- mass balance by certain non-governmen-
lacking. The global chemical recycling ling, at these processes typically pro- tics into its constituent parts. Thermal de- tal organizations (NGOs), mechanical re-
capacity has the potential to grow 8x duce more than one output. As a result, polymerization is a subgroup of chemical cyclers, and waste management compa-
from its current position by 2029 if all the input recycled material must be dis- recycling that involves processes that nies. NGOs often say that the production
projects (including pre-FID) come to tributed to various outputs, complicating break plastic down with heat and pres- of fuels in processes such as pyrolysis
fruition, according to data from the ICIS the mass balancing process. Since ther- sure. One example of a thermal depoly- should not count as recycling because the
Recycling Supply Tracker – Chemical. mal depolymerization technologies (i.e., merization process is pyrolysis, which is production of fuel does nothing to reduce
pyrolysis and gasifi cation) are expected mainly used to turn polyolefi ns (PO) such the reliance on virgin plastic and the fuel
For the chemical recycling indus- to have the largest growth globally based as polyethylene (PE) and polypropylene itself cannot be recovered once it is used
try to realize future growth, it would be on announced plants, mass balance is (PP) into pyrolysis oil. (not closed-loop recycling). However, if
benefi cial to establish clear guidelines as now at the center of many discussions. thermal depolymerization is considered
to how companies can allocate chemi- Pyrolysis oil – whether directly or recycling, NGOs believe that free al-
cally recycled material to their products Chemical recycling and mass balance after being refi ned – is mixed with virgin location should not be adopted. NGOs – Source: ICIS
as they try to hit recycling targets. The Mass balance is a method of book- material before being further processed. along with mechanical recyclers and this style of mass balance as being more Regional trends
lack of guidance in this area adds to the keeping to ensure proper allocation of This mixing happens early in the supply waste managers – agree in principle that scientifi cally justifi able – i.e., it better Currently, the offi cial adoption of
overall uncertainty around chemical re- input material in the fi nal product. As chain, and once it does, the virgin mate- a free allocation approach would lead to aligns with how the recycling units are chemical recycling in legislation is un-
cycling from a legal standpoint, which the chemical recycling industry conti- rial is indistinguishable from the recycled unreliable recycling claims about recyc- realistically distributed in the fi nal output. clear, while mass balance considera-
negatively impacts investment in the nues to grow and mature, the concept of material. At this point, mass balance led content to consumers, with recycled tions are further down the road. In the
nascent industry. Investments in chemi- mass balance is becoming increasingly takes effect to keep track of the recycled material that should have been allocated Fuel-exempt approach United States, for example, the adoption
cal recycling are important to broaden- important to maintain clarity on how the portion of the overall mixture. to fuels or other outputs being claimed on There are other mass balance ap- of chemical recycling is happening on a
ing the scope of recyclable feedstock by recycled material is being allocated. plastic products. proaches that are not as extreme as either state-by-state basis, with 25 states cur-
targeting those plastics and their specifi c As this mixture continues to be pro- free allocation or proportional allocation, rently onboard. Mass balance claims, on
applications that are not suitable for Chemical recycling is an umbrella cessed, it is separated into various chemi- Mechanical recyclers and waste man- but instead lie somewhere in the middle. the other hand, are typically certifi ed by
mechanical recycling. term that encompasses many different cals and fuels, all with their own potential agers have additional concerns about The fuel-exempt approach, for example, external bodies such as the Internation
end-use applications. Although the total the incentives a free allocation approach dictates proportional allocation of re- Sustainability and Carbon Certifi cation
amount of recycled material that was in- provides. The added cost benefi ts could cycled units to fuels, while allowing free (ISCC) system.
putted at the start of the process is known, lead to a competitive market edge for allocation of the remaining recycled units
how these recycled units are allocated to the chemical industry on recycling, put- to all other outputs. The European Union (EU), for com-
each output will vary based on the type of ting chemical recycling in a position parison, is developing an EU-harmonized
mass balance approach adopted. to compete with mechanical recycling Polymers-only approach method. Directive 2008/98/EC (Waste
rather than complement it. Furthermore, Alternatively, there is the ‘polymers- Framework Directive) – the piece of
Different approaches to mass balance the parties cite that adopting a method only’ method, which dictates propor- legislation most cited to provide a legal
of mass balance that allows for an easy tional allocation of recycled units to all defi nition of recycling – does not make
Free allocation integration with current technologies used outputs except polymers, which can be the full recognition of chemical recycling
Free allocation is a method of mass to produce virgin plastic would hinder the allocated freely. clear. In the EU, mass balance claims are
balance that allows for the total allocation transition away from virgin plastic. similarly certifi ed by bodies such as the
of recycled material to be in any output. Each of these methods have their ISCC system.
This allocation method would benefi t Proportional allocation pros and cons, and ultimately lead to
advancements in the chemical recycling Those who oppose free allocation different claims of recycled material Regardless of the type of mass
industry by providing the best cost in- suggest a stricter method of mass balance content in the various outputs. balance approach adopted, without the
centives to chemical recyclers, making called proportional allocation as an alter- coadoption of chemical recycling and
investing in the space more appealing. native. This method of mass balance pro- Table 1 shows possible virgin and mass balance, the chemical recycling
* Final Investment Decision; ** Includes pyrolysis-based projects (all types, for all relevant polymers; Although they cannot claim more recyc- portionally distributes recycling units to recycled combinations for different industry will continue to be shrouded
excludes tyre pyrolysis), gasifi cation, glycolysis, hydrolysis, and methanolysis projects led material than was inputted, they each output based on the amount formed. output scenarios depending on the mass in uncertainty, leading to hampered
Source: ICIS Recycling Supply Tracker – Chemical, 2024. can claim all the recycled input in the Advocates for proportional allocation cite balance approach adopted. industry growth.

172 Chemical Weekly October 29, 2024 Chemical Weekly October 29, 2024 173

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