Life-cycle inventory (LCI) for assessing environmental impacts of plastic-waste treatment systems

Overview
This repository provides a harmonised life-cycle inventory (LCI) framework for assessing the environmental impacts of plastic-waste treatment systems, including recycling, incineration with energy recovery, landfilling, open disposal, and international transport. The LCI is parameterised with country-specific electricity mixes and treatment technologies and can be combined with externally defined waste-flow scenarios, including those derived from international trade statistics.

The LCI framework underpins the published study “Shift to intra-EU-OECD trade enhanced environmental benefits after Basel Convention Plastic Waste Amendments” (Resources, Conservation and Recycling, 2025), but is released here as a stand-alone, reusable research resource applicable to broader scenario-based LCA and MFA studies of plastic waste systems.

Contents

1. Trade-data processing and reconciliation

• code_bc_z3.py: Python toolkit for data retrieval, reconciliation, and scenario analysis, including:

  • Retrieval of bilateral plastic-waste trade data from UN Comtrade

  • Harmonisation of yearly trade records and treatment of missing or zero mass values

  • Unit-price-weighted reconciliation of export–import reporting asymmetries

  • Country selection and trade-share calculation

  • Assignment of transport modes and construction of international transport routes

  • Scenario-based trade-flow visualisation and LCA preparation

2. Life-cycle inventory (LCI) for plastic-waste trade

• LCI_model.xlsx: Parameterised LCI model for scenario-based LCA, including:

  • 86 activities (75 waste-treatment, 11 international transport)

  • Activities drawn from ecoinvent 3.8, supplemented with assembled and parameterised processes

  • Country-specific electricity mixes, recycling technologies, incineration with energy recovery, and disposal pathways

The LCI is organised into the following sheets:

• National electricity mix

• Recycling and recycling-residue treatment

• Virgin plastic production

• Incineration (with uncertainty variants)

• Sanitary landfill, unsanitary landfill, open dumping, and open burning

• International transport

• Parameter-scenarios and documentation notes

Scenario LCA is implemented using Activity Browser (Brightway-based).

The corresponding paper has been published in the journal Resources, Conservation and Recycling on August 2, 2025.

For any issues with this repository, please contact: kai.li@om.rwth-aachen.de.

This repository contains the files that support the analysis presented in the paper:

code_bc_z3.py: python scripts for all the calculations and plots included in the affiliated paper. 

Sections include (refer to code cells; heading 1 included only):

1. Import packages
2. Functions and lists defined
3. Retrieve bilateral trade from UN Comtrade database
4. Arrange the data by year
5. Replace zero and empty trade volumes if other weight metrics(altQty or qty) exist
6. Replace zero and empty netweight values from similar trade
7. Balance bilateral trade reporting asymmetries (unit price-weighted approach)
8. Research country selection and trade share
9. Assign transport and build common transport modes 
10. Assign the most common transport to unspecified transport
11. Life cycle inventory of transport
12. Data preparation
13. Figure 2: Plots of trade flow
14. Scenario LCA 
15. Other figures

Examples in LCI_model.xlsx:

The LCI data are organized into ten sheets: ‘National electricity mix(1)’, ‘Recycling(12)’, ‘Recycling residue treatment(10)’, ‘Virgin plastic production(12)’, ‘Incineration(20)’, ‘Sanitary landfill(5)’, ‘Unsanitary landfill(5)’, ‘Open dumping(5)’, ‘Open burning(5)’, and ‘International transport(11)’. Additionally, there are two sheets for 'Parameter-scenarios' and 'Notes'. 

Additional files with the extensions '.pkl' and '.xlsx' are necessary to run the Python scripts provided above.