Predicting Unwanted Deposits



A proposed ASTM International standard will help predict deposits caused by combustion gases in boilers of coal fired power plants.

All interested parties, particularly coal chemists, are invited to join in the development of the standard (WK48796, Practice for Determination of Water-Soluble Alkali Content in Coal). Subcommittee D05.21 on Methods of Analysis is developing the proposed practice.

Unchecked deposits inside boilers in coal-fired power plants can shut down entire units until they are cleaned. There are two processes that produce these problematic kinds of deposits: "fouling" creates deposits at temperatures below that of ash fusion while "slagging" is the means by which molten deposits are formed. A preventative approach for controlling the processes that create deposits is crucial to the industry.

"Modeling based on the coal quality results from laboratory testing is a good way to predict fouling and slagging inside of boilers," says ASTM member Kelly Olenyik, assistant manager of operations and technical services, Standard Laboratories Inc. – Western Division.

Testing to the proposed standard will provide a coefficient that considers the percentage of water-soluble alkalis, water-soluble potassium and sodium oxide. The coefficient will refine the models that are used for predicting coal fouling and slagging, especially in low rank coals.

There will be four main beneficiaries of this standard, once published:

  • Producers will refer to it to categorize the water-soluble alkali content of their coal.
  • Labs will have a robust test method to deliver quantified water-soluble alkali content percentages to their customers.
  • Utilities will be able to rely on water-soluble alkali results generated from the standard for boiler fouling/slagging modeling.
  • Auditors and accreditation bodies will have fair parameters to evaluate users of the method.

contact Technical Information: Kelly Olenyik, Standard Laboratories Inc. - Western Division • Casper, Wyo. • tel +1.307.234.9957 | ASTM Staff: Scott Orthey • Phone: 610-832-9730 | Upcoming Meeting: Oct. 25-28 • Tampa, Fla.

Industry Sectors: 
Energy
Issue Month: 
July/August
Issue Year: 
2015