Overview
Prasus™ is a mass-balanced bio-polypropylene (bio-PP) resin brand launched by Prime Polymer Co., Ltd., a core polyolefin company within the Mitsui Chemicals Group. Introduced in 2023, Prasus represents a breakthrough in circular polyolefins by combining bio-based and recycled feedstocks under the mass balance certification framework.
Prasus enables the production of polypropylene with verified renewable and recycled content while maintaining the identical performance, processability, and quality of conventional fossil-based PP.
Core Technology: Mass Balance Approach
What is Mass Balance?
A chain-of-custody model (ISCC PLUS certified) that tracks sustainable feedstocks through complex petrochemical crackers and polymer plants:
- Sustainable feedstocks enter the cracker (bio-naphtha, pyrolysis oil from plastic waste)
- Co-processing with fossil feedstocks in existing assets
- Allocation of sustainable characteristics to specific output grades via bookkeeping
- Certified output (Prasus) carries verified % bio-based + % recycled content
Prasus Feedstock Composition
- Bio-based polyethylene allocation (from bio-naphtha / bio-ethanol route)
- Recycled polyethylene allocation (from chemical recycling / pyrolysis oil)
- Combined in PP reactor → mass-balanced bio-PP
Result: PP resin with dual sustainability claims — bio-based AND circular.
Product Grades & Properties
Prasus™ Portfolio
| Grade | Bio-based % | Recycled % | Target Applications |
|---|---|---|---|
| Prasus MB | Variable (ISCC) | Variable (ISCC) | General purpose, compounding |
| Prasus HF | High bio-based | High recycled | High-performance, automotive |
| Custom grades | Tailored | Tailored | Specific customer requirements |
Key Properties (vs. conventional PP)
- Identical mechanical performance: Tensile, impact, heat resistance
- Same processability: Injection molding, extrusion, thermoforming
- Regulatory compliance: Food contact, automotive specs, REACH
- Quality consistency: Prime Polymer’s ISO 9001 / IATF 16949 systems
Commercial Deployments
1. Expo 2025 Osaka — National Day Hall Floor Tiles
- Partner: Mitsui Chemicals + Transwood™ (cellulose microfiber composite)
- Application: Floor tiles using Transwood™ with Prasus™
- Significance: World Expo showcase — high-visibility, high-durability public space
- Date: October 2024 announcement, installation 2025
2. Lawson Convenience Store Bags (Japan)
- Partner: Lawson (major konbini chain) + Mitsui Chemicals
- Application: Shopping bags made with Prasus™
- Launch: January 2026 rollout across Lawson stores
- Claim: “Bio & Circular” — sole main material incorporating both bio-PE and recycled PE via mass balance
- Impact: ~14,000 stores, millions of bags/year
3. Automotive Development
- Target: Interior parts, under-hood components, bumpers
- Drivers: OEM recycled content mandates (EU ELV, Japan Green Procurement)
- Status: Sampling with Tier 1s and OEMs
Certification & Compliance
ISCC PLUS Certification
- Scope: Mass balance chain of custody
- Feedstocks: Bio-naphtha (used cooking oil, tall oil), pyrolysis oil (mixed plastic waste)
- Audit: Annual third-party verification
- Claims: “% bio-based (mass balance)”, “% recycled (mass balance)”
Regulatory Alignment
- EU: PPWR (Packaging & Packaging Waste Regulation) — mass balance recognized
- Japan: Plastic Resource Circulation Act, Green Procurement Law
- Global: ISO 22095 (chain of custody), Ellen MacArthur Foundation reporting
Prime Polymer / Mitsui Chemicals Context
Prime Polymer Co., Ltd.
- Established: 2005 (Mitsui Chemicals + Idemitsu Petrochemical JV)
- Ownership: Mitsui Chemicals 65%, Idemitsu 35%
- Capacity: ~1.4 million tons/year PP + PE
- Sites: Chiba, Nagoya, Osaka, Sodegaura (Japan)
- Position: #2 PP producer in Japan
Mitsui Chemicals Group
- Revenue: ¥1.6+ trillion (FY2023)
- Segments: Mobility, Healthcare, Food & Packaging, Basic Materials
- Sustainability: Carbon neutral 2050, 2030 milestones
- Bio-based track record: Bio-PE (since 2010), Bio-PP (Prasus), Bio-PU, Bio-PC
Market Position
Competitive Landscape
| Competitor | Technology | Status |
|---|---|---|
| Prasus (Prime Polymer) | Mass balance bio-PP | Commercial (2023+) |
| Borealis (Bornewables) | Mass balance bio-PP | Commercial |
| SABIC (TRUCIRCLE) | Mass balance bio-PP | Commercial |
| LyondellBasell (Circulen) | Mass balance bio-PP | Commercial |
| Braskem (I’m green) | Bio-PP (direct) | Demo scale |
Prasus Differentiation
- Dual allocation: Bio-based + recycled simultaneously
- Japanese regulatory alignment: First mass balance PP for Japan market
- Composite integration: Transwood™ cellulose microfiber synergy
- Retail proof point: Lawson bags = consumer-facing scale
Future Roadmap
2026-2027
- Expand Lawson deployment (all bag types)
- Automotive qualification (OEM approvals)
- Packaging film grades (cast, BOPP)
2028-2030
- 100,000+ tons/year Prasus capacity allocation
- European production (via Mitsui Chemicals Europe)
- Chemical recycling integration (own pyrolysis oil)
2030+
- Carbon negative grades (bio-char co-sequestration)
- Full circularity: Prasus → use → collect → pyrolysis → Prasus
Sustainability Impact
Per Ton of Prasus (vs. fossil PP)
| Metric | Reduction |
|---|---|
| Fossil carbon | Up to 100% (mass balance allocation) |
| GHG (cradle-to-gate) | 30-70% depending on feedstock mix |
| Plastic waste diverted | Equivalent to recycled % allocation |
Circular Economy Contribution
- Enables mechanical recycling streams (same PP chemistry)
- Drives chemical recycling demand (pyrolysis oil offtake)
- Supports bio-naphtha market scale-up (refinery integration)
Last updated: February 14, 2026 Information sourced from Mitsui Chemicals press releases (Oct 2024, Jan 2026), MarketScreener, Moomoo financial news, Prime Polymer website, ISCC certificate database, and Japanese packaging industry reports