PFBC Residues--Characteristics, Disposal And Utilisation
AUTHOR: Charlotta Nilisson and Lee Clarke
DATE: August 1994
Developments in the management of residues from pressurised fluidised bed combustion (PFBC) systems are reviewed. The sources of residues and the quantities produced; the chemical, physical, and geotechnical characteristics of the residues; and the management of these materials during disposal or utilisation are examined. PFBC systems offer advantages over other coal utilisation technologies in terms of environmental performance, fuel flexibility, and overall efficiency. However, these systems produce large quantities of residues, with properties that differ from the residues discharged from pulverised coal combustion or atmospheric fluidised bed combustion. The residues are a mixture of ash from the coal and sorbent-derived materials.
Results indicate that most PFBC residues would be classified as non-hazardous under existing legislation. Many utilisation options have been suggested for PFBC residues. At present the most favourable uses appear to be in structural fills or soil stabilisation applications. Utilisation of PFBC residues is hampered by the limited quantities of residues produced from the few commercial-scale plants. In future, increased disposal costs may make utilisation a more viable option, providing that residues perform adequately in various applications and they can be used in an environmentally acceptable way.