Industrial symbiosis & by-product exchange platforms

01Overview and value chain

Markers: [EC: EU Circular Economy Action Plan + Ecodesign for Sustainable Products Regulation (Digital Product Passport) | OECD: Environmental biotechnology, Circular bioeconomy | Regulator: EPA (USA), ECHA/REACH (EU), MEE (China)]

Industrial symbiosis and by-product exchange platforms form the coordination layer of the circular economy: rather than converting a residue themselves, they route one plant’s waste heat, water or by-product to a neighbouring firm that can use it as an input. The archetype is Kalundborg Symbiosis in Denmark, running since 1961 and now linking more than 30 partners across water, energy and material streams — it reached its “10 new streams in 10 years” goal in late 2025. The layer is now being digitized: material and digital product passports (Madaster) record the composition of assets and goods so their components can be reused, and blockchain traceability (Circulor) follows materials and embedded carbon through the supply chain. It is a mid-maturity, regulation-pulled industry: mature symbiosis networks sit alongside emerging passport and traceability platforms, and the honest overall risk is medium.

The key directions of industrial symbiosis and by-product exchange are:

1. Industrial symbiosis networks (Industrial Symbiosis Networks): geographic clusters where co-located partners exchange water, energy and by-products — Kalundborg since 1961, and China’s national eco-industrial parks.
2. By-product exchange platforms (By-Product Exchange Platforms): digital and meeting-based platforms that match a firm’s residue to another’s input (International Synergies/NISP, US BCSD Synergize).
3. Material and digital product passports (Material Passports / DPP): digital records of a product’s material composition enabling reuse and recycling, now mandated by the EU Ecodesign for Sustainable Products Regulation.
4. Circular supply-chain traceability (Circular Supply-Chain Traceability): blockchain and IoT tracking of materials and embedded carbon across supply chains (Circulor).

Sectoral value chain

[industrial residue] ──> [matching] ──> [exchange logistics] ──> [secondary reuse]
                                 │
                         (passport + traceability)
                                 │
                                 ▼
[circularity disclosure] <─── [verification] <─────┘

Value chain levels

Cross-cutting technologies of the sector:

• Industrial ecology science (Industrial Ecology Science): material-flow analysis and symbiosis stability research (Yale Center for Industrial Ecology).
• Digital product passports (Digital Product Passports): EU ESPR-mandated records of composition, origin and end-of-life route.
• Extended producer responsibility (Extended Producer Responsibility): regulatory duties that push residual ownership back onto producers, driving exchange.

02US

The United States anchors the science of industrial symbiosis and runs by-product synergy programmes through business-led councils.

symbiosis science, by-product synergy programmes

• Yale Center for Industrial Ecology: the academic home of industrial symbiosis research — Marian Chertow coined the term — and author of “From variance to value: stabilizing circular exchanges in industrial symbiosis networks” (November 2025), addressing how circular exchanges persist over time.
• US Business Council for Sustainable Development (qualitative): runs by-product synergy programmes such as the Houston Water Synergy Project and the Synergize matching methodology that ports the NISP approach to US regions.

03CN

China runs the world’s largest national eco-industrial park programme under its circular-economy association, embedding symbiosis at industrial-zone scale.

national eco-industrial parks, circular-economy association

• China Association of Circular Economy (中国循环经济协会): the national body coordinating circular-economy policy, demonstration eco-industrial parks (EIPs) and by-product exchange across China’s industrial zones — the largest state-organized symbiosis programme globally.
• Zone-scale symbiosis: China’s national demonstration EIPs cluster heavy industry (chemicals, steel, paper) so that one plant’s waste heat, slag or water feeds a neighbour, with the association certifying and aggregating the flows.

04EU

Europe is both the birthplace and the regulator of modern industrial symbiosis, pairing the original Kalundborg network with the Digital Product Passport mandate.

flagship symbiosis network, material passports, supply-chain trust

• Kalundborg Symbiosis (Denmark): the world’s first industrial symbiosis, running since 1961 and linking more than 30 partners; it achieved its “10 new streams in 10 years” goal in December 2025, adding exchanges across water, energy and bio-refinery by-products.
• Madaster (Netherlands): a material-passport platform issuing digital product passports for construction and manufacturing, recording the composition of buildings and goods so their components can be recovered and reused.
• Circulor (United Kingdom): in May 2026 it offered digital product passports with supply-chain trust and assurance, using blockchain to follow battery materials and embedded carbon from mine to product; International Synergies/NISP (qualitative) supplies the by-product matching methodology that originated the field.

05Leading companies and research institutes

06Tech stack and innovations

The stack runs from century-old geographic clustering to emerging digital passports and blockchain traceability.

1. Industrial symbiosis networks (Industrial Symbiosis Networks):
   • co-located partners exchange water, energy and by-products under long-term contracts, cutting virgin input and disposal.
   • case: Kalundborg’s 30+ partners achieved “10 new streams in 10 years” by late 2025; China’s EIPs replicate the model at zone scale.
2. Material and digital product passports (Material Passports / DPP):
   • digital records of composition, origin and end-of-life route, mandated for product categories under the EU Ecodesign for Sustainable Products Regulation.
   • case: Madaster issues material passports for buildings and manufactured goods to enable component reuse.
3. Circular supply-chain traceability (Circular Supply-Chain Traceability):
   • blockchain and IoT track materials, embedded carbon and provenance across multi-tier supply chains.
   • case: Circulor’s May 2026 digital product passports with supply-chain trust follow battery minerals from mine to product.

07Value chains and production pipelines

Industrial pipeline of a by-product exchange (EU ESPR DPP / ISO 59020)

┌───────────────────────────┐      ┌───────────────────────────┐
│ 1. Residue identification │ ───> │ 2. Synergy matching       │
└───────────────────────────┘      └───────────────────────────┘
                                                 │
                                                 ▼
┌───────────────────────────┐      ┌───────────────────────────┐
│ 4. Secondary-input reuse  │ <─── │ 3. Exchange logistics     │
└───────────────────────────┘      └───────────────────────────┘
              │
              ▼
┌───────────────────────────┐      ┌───────────────────────────┐
│ 5. Passport verification  │ ───> │ 6. Circularity disclosure │
└───────────────────────────┘      └───────────────────────────┘

Stage 1: Residue identification

Each firm catalogs its available waste, residual heat and water streams together with volume, quality and temporal profile.

Stage 2: Synergy matching

A platform or symbiosis secretariat matches each residue to a neighbouring user’s input need — the core methodology of NISP/International Synergies and US BCSD Synergize.

Stage 3: Exchange logistics

Piping, conveyors, tankers and contracts route the stream between sites; Kalundborg’s decades of piped water, steam and gas exchanges are the reference.

Stage 4: Secondary-input reuse

The receiving plant integrates the delivered stream as a production input, displacing a virgin resource and avoiding disposal.

Stage 5: Passport verification

A material or digital product passport (Madaster) and blockchain traceability (Circulor) record the composition and flow, verifying the circular claim.

Stage 6: Circularity disclosure

The verified flows roll up into CSRD/ESRS E5 (resource use and circular economy) and TNFD reporting, making industrial symbiosis auditable to investors and regulators.