Opportunities for developing specialty chemicals and advanced materials from coals

The main objective of this paper is to explore the potentials and possible ways to develop high-value chemicals and materials from coals and coal liquids. Recently it has become clear that more extensive use of fossil fuels, especially coal, may be constrained not only by economics, but also by environmental considerations such as SO_x and NO_x emissions and global warming. Therefore, new concepts are required, and significant advances are essential for the effective utilization of coals in the next century. Both from economic and environmental viewpoints, developing high-value chemicals and materials from coals and coal liquids should lead to more efficient and environmentally safe utilization of the valuable carbonaceous resources. It is important to explore the routes and methods for developing specialty chemicals, which are difficult to obtain or not readily available from petroleum, advanced polymeric engineering materials, and high-performance carbon materials. Recent years have seen significant progress in the development and application of new, industrially important aromatic engineering plastics, thermoplastic materials, liquid crystalline polymers, and membrane materials. Many of the monomers for these materials can be prepared from one- to four-ring aromatics such as alkylated benzenes, naphthalene, biphenyl, anthracene, phenanthrene, pyrene, phenol, and carbazole. Especially important are 2,6-dialkylnaphthalenes, 4,4′-dialkylbiphenyls, and 1,4-dialkylbenzenes. The large-volume application of aromatic high-performance polymers depends on lowering their cost, which in turn is largely determined by the cost of the aromatic monomers. By developing the critical aromatic chemicals from coals, coal-to-chemicals research could contribute significantly to high-technology development. Potential large-volume markets for materials from coal can be stimulated by developing high-performance carbon materials such as carbon fibers and graphites, and by developing ways to make advanced adsorbents for environmental applications such as air and water purification.