Life cycle assessment for all organic chemicals

TL;DR

The paper introduces CRYSTAL, a machine learning framework that generates comprehensive, transparent life cycle inventory data for over 70,000 organic chemicals, enabling better sustainability assessments and targeted environmental interventions.

Contribution

CRYSTAL provides the first large-scale, molecular structure-based LCI database for organic chemicals, improving transparency and consistency in chemical life cycle assessments.

Findings

Created a database with over 110,000 LCI datasets for 70,000+ chemicals

Identified 50 environmental hotspots in chemical production

Pinpointed key hub chemicals critical for downstream processes

Abstract

Chemicals are embedded in nearly every aspect of modern society, yet their production poses substantial sustainability concerns. Achieving a sustainable chemical industry requires detailed Life Cycle Assessment (LCA); however, current assessments face many unknowns due to limited, partly inconsistent, and untransparent data coverage since existing Life Cycle Inventory (LCI) databases account for only a tiny fraction of traded chemicals. Here, we introduce the Chemical RetrosYnthesiS for Transparent Assessment of Life-cycles (CRYSTAL) framework, which automatically generates consistent and transparent LCI data for organic chemicals based on their molecular structure using retrosynthesis and machine-learned gate-to-gate inventories. Using the predictive power of CRYSTAL, we create a consistent database for more than 70000 organic chemicals, comprising over 110000 transparent LCI datasets that quantify both feedstock and energy demands, together with associated auxiliary materials, biosphere flows, and waste flows. From this comprehensive database, we identify 50 key environmental hotspots driving high impacts of organic chemical production across multiple environmental categories and pivotal hub chemicals that are most critical for downstream chemical production. In providing this comprehensive data foundation, the CRYSTAL framework offers systematic guidance for targeted engineering and policy interventions. Its transparent, modular nature is designed to shift chemical LCA from a reliance on "unknown unknowns" to a collaboratively improvable mapping of "known unknowns".