Overview
ISO 18466:2016 specifies a balance method to determine the biogenic fraction of CO2 in stack gas from stationary combustion sources, in particular Waste‑for‑Energy (WfE) plants. The method uses a mathematical model that combines online stack gas composition (O2 and CO2) and plant operating data with the elemental composition (C, H, O, N, S) of the biogenic and fossil components of the fuel. Note: the calculation method is intended for mixed fuels only.
Keywords: ISO 18466, biogenic fraction, CO2 in stack gas, balance method, Waste to Energy, WfE, stationary source emissions.
Key Topics and Requirements
- Input and output stream parameters: requirements for measuring fuel feed, auxiliary fuels, combustion air and stack gas composition.
- Sampling and test methods: guidance on representative sampling of input (fuel) and output (stack) streams and calibration/quality assurance references.
- Balance calculations: detailed mass, ash, carbon, energy, oxygen consumption and water balances to partition CO2 into biogenic and fossil fractions.
- Composition of organic matter: use of elemental (moisture‑ and ash‑free) compositions for both biogenic and fossil fractions as model inputs.
- Mathematical model and data reconciliation: numerical solution routines, Jacobian formulation, plausibility checks and uncertainty budget methodology for model outputs.
- Operational requirements: installation and ongoing operation routines to run the online model and to integrate plant data streams.
- Verification: model outputs can be verified against radiocarbon (C-14) methods (e.g., ISO 13833) where applicable.
- Normative references: cross‑references to ISO 12039 and relevant EN standards for automated measuring systems and QA (EN 14181, EN 15259, EN 15267‑3).
Applications and Users
ISO 18466 is practical for:
- WfE and waste‑to‑energy plant operators implementing continuous monitoring and reporting of greenhouse gas sources.
- Emissions engineers and environmental compliance teams performing carbon accounting, sustainability reporting and regulatory reporting.
- Environmental auditors and laboratories validating biogenic/fossil CO2 fractions and reconciling online model data with periodic radiocarbon sampling.
- Designers of emissions monitoring systems integrating stack gas analyzers with plant process data for real‑time biogenic CO2 estimation.
Benefits include enabling online modelling of biomass/fossil CO2 ratios for operational control, emissions reporting and verification, and supporting compliance with climate and waste‑management policies.
Related Standards
- ISO 12039 - automated measuring systems (CO, CO2, O2)
- ISO 13833 - radiocarbon (C‑14) method for biogenic fraction
- EN 14181, EN 15259, EN 15267‑3 - QA, measurement site requirements and certification of automated measuring systems
Keywords: stack emissions, carbon balance, online monitoring, biogenic CO2 fraction, ISO standards.