The combustion of pulverised coal in the furnace of a coal fired power station boiler results in the production of a number of solid by-products, more accurately classified as CCP's (coal combustion products). This terminology reflects a more positive view and is in keeping with the concept of industrial ecology, being an approach that seeks to use one industries by-product output as another industries raw material inputs.
The beneficial use of CCP's from coal consumption is an important for the sustainable use of coal, within an increasingly resource finite and carbon emission constrained society. While the principal output from coal combustion is energy, significant quantities of by-products in the form of CCP's are also produced. In life cycle terms, the opportunities to exploit the low energy embodied in CCP's such as fly ash, furnace bottom ash, boiler slags and cenospheres are extensive.
CCP's, being highly processed materials (from the actions of milling and thermal processing) can, if used effectively, displace the use of other energy-intensive raw materials (product replacement). This results in the conservation of finite mineral resources and the reduction or displacement of emissions, through the recovery and reuse of CCPs. An example is shown below; note that percentages are not exact.
Cement that includes CCPs such as fly ash can create a reduction of finite resourches such as limestone and clay by up to 30% (Coal Combustion Products Handbook 2nd Edition).
Reduction (in greenhouse gas terms) is therefore tangible and within an increasingly carbon constrained society is a worthy motivation for developing innovative methods for recovery and use. Based on current national government policy and growing public concern for carbon dioxide and methane reduction, it appears inevitable that a carbon pricing mechanism will re-emerge, and that it will include a suite of offset options that recognise reductions in the use of fossil fuels. This has and will bring further incentive to recover and utilise CCP's now and in the future.
Australian producers and marketers of power station ash formed the Ash Development Association of Australia (ADAA) with the objective of investigating and developing market opportunities for the use of these materials in various industry applications such as construction, agriculture and manufacturing. The Association has and continues to deliver on this objective by striving to increase awareness to generators, processors, regulators and end users of the benefits to both the environment and their organisations that arise from the increased utilisation of these industry by/co-products for relevant industries, the community, and ultimately the environment.
Strategically, this has involved the execution of three primary objectives:
- The initiation, analysis and dissemination of fundamental (pre-commercial) research and development initiatives in the recovery, processing and use of CCP's.
- Advocating for the potential beneficial end uses and applications of CCP's to governments, regulators, and relevant industry organisations, both domestically and internationally.
- Providing a regular forum for the exchange, consultation and analysis of relevant industry developments and information.