Overview

ISO 21660-2:2025 - Solid recovered fuels - Determination of moisture content using the oven dry method - Part 2: Determination of total moisture by a simplified method specifies a practical, on‑site oven drying procedure for measuring total moisture in solid recovered fuels (SRF). Designed for routine production control where very high analytical precision is not required, the method uses controlled oven drying and mass loss to report moisture on a wet basis.

Key topics and technical requirements

Scope: Applicable to all solid recovered fuels for routine moisture control; alternatives (e.g., Karl‑Fischer titration - ISO 760) are recommended when oil fractions are high.
Drying conditions: Standard drying at 105 °C ± 2 °C in an air atmosphere with 3–5 air changes/hour. For materials with large oil fractions, use a lower temperature (e.g., 50 °C ± 10 °C) and extend drying time.
Apparatus: Controlled drying oven, non‑corrodible drying containers (metal, glass, porcelain), balance readable to 0.1 g.
Sample preparation: Follow ISO 21645 and ISO 21646. Test portion mass ≥ 300 g (preferably >500 g); for large particles (top size 100 mm) 1–2 kg preferred. Max particle size for test material often reduced (e.g., ≤30 mm).
Procedure: Weigh container and sample, dry until constant mass. Hot weighing must be done within 10–15 s to prevent re‑absorption. Mass constancy: change ≤ 0.2% of total loss during a further 60 min at drying temperature. Duplicate determinations required.
Calculation & reporting: Moisture expressed as a percentage (wet basis), results to two decimal places, mean rounded to 0.1%. Test report must include lab ID, date, sample ID, reference to ISO 21660-2:2025, results, deviations and observations.
Safety/notes: Risk of self‑ignition for some materials when drying at 105 °C; volatile extractives can bias “moisture” results - standardized conditions are essential for comparability.

Applications and users

Who benefits from ISO 21660-2:2025:

SRF production and trading companies for routine on‑site quality control
Energy and waste‑to‑energy facilities monitoring fuel moisture for combustion performance
On‑site laboratories and quality assurance teams
Regulatory and conformity assessment bodies checking compliance and sampling consistency

Practical value:

Quick, reproducible moisture checks that support process control, storage decisions, and fuel acceptance criteria.
Clear guidance on when to use alternative methods (e.g., Karl‑Fischer) or reduced temperatures for oily materials.

Related standards

ISO 21660 series (other parts for total moisture)
ISO 21637 - Vocabulary for solid recovered fuels
ISO 21645 - Sampling methods
ISO 21646 - Sample preparation
ISO 760 - Karl‑Fischer titration method (alternative moisture determination)

Keywords: ISO 21660-2:2025, solid recovered fuels, moisture content, oven dry method, total moisture, routine production control, sample preparation, Karl‑Fischer.

Overview

Key topics and technical requirements

Scope: Applicable to all solid recovered fuels for routine moisture control; alternatives (e.g., Karl‑Fischer titration - ISO 760) are recommended when oil fractions are high.
Drying conditions: Standard drying at 105 °C ± 2 °C in an air atmosphere with 3–5 air changes/hour. For materials with large oil fractions, use a lower temperature (e.g., 50 °C ± 10 °C) and extend drying time.
Apparatus: Controlled drying oven, non‑corrodible drying containers (metal, glass, porcelain), balance readable to 0.1 g.
Sample preparation: Follow ISO 21645 and ISO 21646. Test portion mass ≥ 300 g (preferably >500 g); for large particles (top size 100 mm) 1–2 kg preferred. Max particle size for test material often reduced (e.g., ≤30 mm).
Procedure: Weigh container and sample, dry until constant mass. Hot weighing must be done within 10–15 s to prevent re‑absorption. Mass constancy: change ≤ 0.2% of total loss during a further 60 min at drying temperature. Duplicate determinations required.
Calculation & reporting: Moisture expressed as a percentage (wet basis), results to two decimal places, mean rounded to 0.1%. Test report must include lab ID, date, sample ID, reference to ISO 21660-2:2025, results, deviations and observations.
Safety/notes: Risk of self‑ignition for some materials when drying at 105 °C; volatile extractives can bias “moisture” results - standardized conditions are essential for comparability.

Applications and users

Who benefits from ISO 21660-2:2025:

SRF production and trading companies for routine on‑site quality control
Energy and waste‑to‑energy facilities monitoring fuel moisture for combustion performance
On‑site laboratories and quality assurance teams
Regulatory and conformity assessment bodies checking compliance and sampling consistency

Practical value:

Quick, reproducible moisture checks that support process control, storage decisions, and fuel acceptance criteria.
Clear guidance on when to use alternative methods (e.g., Karl‑Fischer) or reduced temperatures for oily materials.

Related standards

ISO 21660 series (other parts for total moisture)
ISO 21637 - Vocabulary for solid recovered fuels
ISO 21645 - Sampling methods
ISO 21646 - Sample preparation
ISO 760 - Karl‑Fischer titration method (alternative moisture determination)

Keywords: ISO 21660-2:2025, solid recovered fuels, moisture content, oven dry method, total moisture, routine production control, sample preparation, Karl‑Fischer.

ISO 21660-2:2025 PDF

Технические детали

Abstract

Overview

Key topics and technical requirements

Applications and users

Related standards

Похожие стандарты

Abstract

Overview

Key topics and technical requirements

Applications and users

Related standards

Похожие стандарты

Determination of water -- Karl Fischer method (General method)

Solid recovered fuels - Methods for sampling (ISO 21645:2021)

Solid recovered fuels - Sample preparation (ISO 21646:2022)