The IEA Clean Coal Centre maintains a number of databases on all aspects of clean coal technologies and their use. They are available here and are free to view.
Is an encyclopedia of coal. It is compiled from reports published by the IEA Clean Coal Centre and is searchable on a free to view basis.
Clean Coal Technologies
Is a fully searchable database that is freely available. It holds accurate, yet brief, descriptions of the many clean coal technologies and so it is a useful reference tool.
The standards relevant to coal combustion are reported for each country or region listed and are available on a free to view basis.