Mass Balance: Unlocking a Circular Economy for the Chemical Industry
The mass balance approach is rapidly emerging as a key enabler of the circular economy for the chemical industry. Unlike mechanical recycling, which struggles to process complex material streams, mass balance allows companies to track recycled chemical feedstocks through highly integrated production systems. This insight from the Ellen MacArthur Foundation and company project explains how mass balance can help industries meet climate goals, reduce fossil dependency, and create certified products with traceable recycled content, without disrupting existing manufacturing assets.
Executive Summary
Realising a circular economy for products and primary materials may appear achievable, but reclaiming the tens of thousands of compounds used in paints, adhesives, and additives for recycling seems daunting. However, economically viable solutions exist. This white paper examines how the mass balance approach can offer a robust and auditable method for tracking recycled feedstock in complex chemical manufacturing processes, thereby supporting the transition to a circular economy in the chemical sector.
The chemical industry, operating with high efficiency at world-scale facilities, relies on a narrow set of feedstocks to produce an enormous array of compounds. Yet, it recycles very little of its outputs, with only ~9% of plastics globally being recycled. Since many chemicals are used in mixed or contaminated applications, traditional separation is often infeasible. Instead, breaking them down into simpler chemical building blocks for reuse offers a viable alternative.
Unlike mechanical recycling, chemical recycling, through processes such as pyrolysis or gasification, can return materials to a virgin-grade feedstock. But because recycled and virgin feedstocks are blended in production, physical traceability is impossible. This is where the mass balance method becomes essential. It enables manufacturers to allocate recycled content to outputs based on rigorous input-output accounting rules, ensuring transparency and credibility.
Mass balance is already used in sustainability programs such as FSC and BCI. For chemical recycling to succeed, a standardized system of rules and allocation methods must be adopted, often based on lower heating value (LHV) rather than mass alone. This ensures fair tracking of feedstock conversion, even when recycled content varies in composition and chemical value.
By establishing international standards for mass balance, the chemical industry can accelerate the use of recycled materials, satisfy downstream demand, and enable transparent claims around recycled content. This is not a substitute for mechanical recycling, but a critical complement that can scale circularity for hard-to-recycle inputs.
To unlock its full potential, broader stakeholder participation is now essential for co-developing and harmonizing these mass balance standards for global application.
Key points of this white paper discuss the implementation of a mass balance approach to enable a circular economy for chemicals, with a focus on the recycling and traceability of recycled feedstock in chemical production.
Enabling a Circular Economy for Chemicals
The mass balance approach offers a viable solution for integrating recycled feedstock into the chemical production process, promoting a circular economy. This method ensures traceability and accountability of recycled materials, addressing the challenges of recycling complex chemical products.
Current State of Chemical Recycling
The chemical industry has low recycling rates, with only 9% of plastics being recycled globally. There is an urgent need to develop systems that can effectively loop back non-consumable products into production.
- The chemical industry is valued at over $2.5 trillion globally.
- Current recycling rates for major chemical products are very low.
- A new approach is needed to enhance recycling efforts.
Mass Balance Approach Explained
The mass balance method allows for the tracking of recycled content in chemical production, ensuring that the amount of recycled feedstock entering the system equals the amount leaving. This approach is essential for integrating recycled materials into existing chemical processes.
- Mass balance accounting is a chain of custody method used to trace material flows.
- It is suitable for complex chemical recycling scenarios.
- Allocation rules based on chemical value-related properties are proposed for effective tracking.
Importance of Standardization in Recycling
Standardizing the mass balance approach is crucial for creating a reliable market for recycled chemicals. A standard set of rules and guidelines will facilitate the use of recycled materials across the industry.
- A standardized mass balance approach can enhance market flexibility.
- Clear communication about recycled content is essential for consumer understanding.
- A standard protocol is needed for credible claims regarding recycled content.
Challenges in Chemical Recycling
The complexity of chemical products and their combinations makes recycling challenging, as many chemicals are used in small quantities as additives. This complicates the separation and recycling processes.
- Chemicals are often mixed and contaminated, making separation difficult.
- Mechanical recycling has limitations for complex materials.
- Chemical recycling can generate virgin-grade feedstock but requires robust systems for tracking.
Chain of Custody Models Overview
Various chain of custody models exist to ensure transparency in the recycling process, with the mass balance model being particularly suited for the chemical industry. These models help maintain trust and accountability in the supply chain.
- The four leading chains of custody models include identity preservation, segregation, mass balance, and book and claim.
- The mass balance model tracks total content without physical separation.
- Standardization and third-party certification are necessary for credibility.
Future Directions for Chemical Recycling
To achieve a circular economy, it is essential to develop systems that can effectively recycle a wide range of chemicals. This involves collaboration among stakeholders to create standards and practices that facilitate the use of recycled materials.
- A collaborative approach is needed for standards development.
- The goal is to increase the use of renewable and recyclable feedstock.
- The transition to a circular economy requires innovative recycling solutions.
Recycled Materials in Chemical Production
The integration of recycled materials as feedstock in chemical production presents a significant opportunity to reduce reliance on fossil resources and promote a circular economy. Co-feeding recycled and virgin materials enables the production of the same high-quality end products with minimal investment.
- Recycled feedstock is treated as a raw material in chemical manufacturing.
- Co-feeding enables the chemical industry to transition towards a circular economy.
- Existing production plants can utilize recycled materials with minimal upfront costs.
- The mass balance approach allows for precise accounting of recycled content in products.
Mass Balance Approach for Recycled Content
The mass balance approach facilitates the allocation of recycled feedstock to products, ensuring that the input and output match within defined system boundaries. This method is essential for maintaining transparency and traceability in the recycling process.
- The approach requires determining the fossil feedstock needed for production.
- It involves defining system boundaries in space and time for accurate tracking.
- The system must include interconnected production assets for effective balancing.
- Annual balancing is typically sufficient for most applications.
Allocation Rules for Mass Balancing
Different allocation methods, such as mass allocation and lower heating value (LHV), are necessary to account for the varying chemical values of feedstocks. The choice of method impacts the amount of recycled content that can be claimed.
- Mass allocation is suitable for similar compositions but may be inadequate for complex mixtures.
- Carbon counting can misrepresent the role of non-carbon intermediates in synthesis.
- LHV is preferred for its ability to reflect the actual value of feedstocks.
- Accurate characterization of feedstock is crucial to avoid dilution effects.
Qualified Credit Transfers in Mass Balance
Qualified credit transfers (QCTs) enable the administrative transfer of recycled material credits within a defined system boundary, promoting efficiency in the circular economy. This model helps avoid unnecessary transportation and redundant assets.
- QCT can accelerate the transition to a circular economy by facilitating credit transfers.
- Strict qualifying conditions are necessary to ensure transparency and reliability.
- The model is distinct from unrestricted Book & Claim systems.
- Multi-stakeholder standards are needed to define acceptable conditions for credit transfers.
Practical Guidelines for Mass Balance Allocation
Establishing clear rules for mass balance allocation is essential for the effective integration of recycled feedstock in chemical production. These rules should address the complexities of different feedstock types and their respective values.
- Mass-on-mass balance is straightforward for identical recycled materials.
- System boundaries must be defined for accurate mass balance calculations.
- The feedstock demand can be expressed in raw material units (RMUs) for flexibility.
- A comprehensive understanding of the chemical value of feedstocks is necessary.
Recommendations for Chemical Recycling Standards
To support the growth of chemical recycling, a regulatory framework and standardized protocols are needed. These standards should ensure that recycled content is treated in the same manner as virgin materials.
- A global standard for mass balance definitions and calculations is essential.
- Environmental and societal benefits of recycled content must be transparent to consumers.
- Certification systems should be established to validate claims of recycled content.
- Life cycle assessments should be conducted to optimize the impacts of chemical recycling.
Future Steps for Mass Balance Implementation
The development of standards for mass balance in chemical recycling is crucial for the successful implementation of this process. Engaging a diverse range of stakeholders will help create a consensus on the application of these standards.
- Options for continuing work include developing private standards or adapting existing ones.
- Governmental mandates can support the establishment of harmonized standards.
- Increasing stakeholder involvement is key to broadening consensus on mass balance applications.
- The goal is to facilitate the use of recycled materials in new products effectively.
Learn more:
You can return to the main Market News page, or press the Back button on your browser.
