ISO 609:1996 PDF

Overview

ISO 609:1996 - Solid mineral fuels - Determination of carbon and hydrogen - High temperature combustion method describes a laboratory high-temperature combustion procedure for determining the total carbon and total hydrogen in hard coal, brown coal, lignite and coke. The method burns a known mass of sample in oxygen at 1 350 °C, converts carbon to CO2 and hydrogen to H2O, absorbs the combustion products in reagents and determines amounts gravimetrically. Results include carbon in carbonates and hydrogen in moisture and structural water; corrections for moisture and mineral carbonates are described where applicable.

Key topics and technical requirements

• Scope: Applicable to hard coal, brown coal, lignite and coke; includes water determination during combustion and optional CO2 determination for carbonate correction.
• Principle: High-temperature combustion in an impervious tube with oxygen; absorption of H2O and CO2 by a series of reagents and gravimetric analysis.
• Reagents and materials: Typical reagents include magnesium perchlorate (for water), sodium hydroxide on an inert base (for CO2), alumina, sodium tetraborate titrant, hydrogen peroxide, and a mixed indicator. Safety warnings note toxic/corrosive reagents and special disposal/regeneration concerns (e.g., magnesium perchlorate).
• Apparatus: Furnace capable of 1 350 °C, refractory combustion tube, Midvale tubes or similar absorption train, combustion boats, silver gauze roll (to trap chlorine and sulfur oxides), flowmeters and a pusher for sample boats.
• Procedure essentials: Conditioning and calibration of absorption trains; locating and maintaining a silver gauze roll; burning a measured test portion and gravimetric measurement of absorbed products; applying corrections for moisture and carbonate-bound carbon.
• Quality control: Conditioning of Midvale tubes, periodic cleaning of silver gauze, limits on sulfur retention to avoid overloading the trap.

Applications and users

Who uses ISO 609:1996:

• Analytical laboratories performing coal analysis and quality control
• Power plants and utilities for fuel characterization and combustion optimization
• Coke producers and metallurgical operations monitoring feedstock composition
• Environmental reporting and carbon accounting where accurate fuel carbon/hydrogen data are required
• Research institutions comparing calorific properties and combustion behavior

Practical uses:

• Determining fuel composition for combustion efficiency and emissions estimates
• Routine quality control of coal and coke consignments
• Data input for heat value calculations and mass-balance studies

Related standards

Standards referenced in ISO 609:1996 include:

• ISO 625:1996 (Liebig method alternative)
• ISO 925 (CO2 determination)
• ISO 331, ISO 687, ISO 1988, ISO 2309, ISO 5068, ISO 5069-2 and others cited for sampling, moisture determination and sample preparation.

Keywords: ISO 609:1996, solid mineral fuels, carbon and hydrogen determination, high temperature combustion, coal analysis, coke testing, Midvale tube, silver gauze, laboratory combustion method.