Reactions: Coal as a raw material, an elemental game

Letters to the editorThe challenge of coal as a raw materialThe article on coal as a raw material correctly identifies the key problem with current technologies: the enormous carbon dioxide release from the standard processes. Plants relying on Fischer-Tropsch conversion of synthesis gas or on variants of Bergius direct hydrogenation of coal are basically CO2 factories that produce liquid hydrocarbons as a by-product. Nonetheless, coal has tremendous potential as a source of chemicals—mainly aromatics—and as a basis for making an array of carbon materials. The latter, in particular, could have applications in batteries and supercapacitors; coal-derived carbon fibers could be used in wind-turbine blades. The challenge to chemists is to develop new routes to these valuable products that would form substantially less CO2 and other low-value substances or wastes. A possible general strategy might be to apply the tenets of green chemistry to coal conversion. This is a wide-open opportunity that has significant potential payoffs in products useful in renewable energy applications. Having worked with coal for 50 years, I can attest that this won’t be easy, but why work on easy problems?Harold Schobert Jordan, MinnesotaFun and games with elementsAmong other changes to C&EN, I have noticed the crossword puzzle in each issue. I am not an avid crossword solver, but I appreciate the playful addition, and I want to suggest one of my own.Now retired, I try to keep in shape by taking long walks, and I have a mental game that I like to play. I call it