I also do not like the term clean coal because clean coal does not exist. When they say clean coal they are saying process's are used so that coal powered plants emit less environmentally harmful pollutants and more energy is produced from the same amount of coal (Carbon dioxide is stored under ground instead of released into the atmosphere, is one way the polluting is reduced). The plants are more environmentally friendly than existing coal plants but are far from clean. Strip mining, mountaintop removal, and underground coal mining (some means of harvesting coal) will still be amongst the dirtiest and most destructive ways of making energy and the so called clean power plants will still release harmful pollutants into the air, just a smaller number of them. Coal miners will continue getting lung cancer, dying via accidents, forests will still be stripped for coal, explosives will still blast poisons into the air, waterways will still have dangerous pollutants enter them from the process of getting the coal, etc., and coal, like oil, is also a fossil fuel with a limited supply and takes millions of years to form (though it is the most abundant fossil fuel available in the USA at this time). There are laws that try to limit the damage done, Surface Mining Control and Reclamation Act of 1977 is one, but pollution, health problems, and environmental problems will still be caused by 'clean' coal plants.
My opinion on 'clean' coal is that existing plants that use coal should take as many steps to reduce their environmental and health impact as possible but new plants should not be created that uses coal, rather cleaner and renewable power sources should be used. I do not suggest using anyone power source everywhere, multiple power sources should be used and which one is best for a given area might not be the best for a different area.
Again since this is at least in part a blog on Japan, here is some info on Japan and coal: Coal powered plants account for around 23% of Japan's energy consumption. Japan imports the majority of it's coal instead of mining it. The reason for this is it is cheaper to import than to mine locally. The amount Japan imports is roughly one quarter of all coal traded worldwide, according to statistics from the government and the International Energy Agency. Japan is very into 'clean' coal technology, leading the world in it's use and implementation. Japan is often trying out new technologies to increase coals efficiency, more so than most countries. Japan teaches other Asian countries how to use coal more efficiently and reduce pollution caused by it. Japan is also actively increasing the use of renewable power and attempting to reduce consumption of power. While this does reduce pollutants the main purpose of these actions are to cut costs and be more self reliant i.e. purchase less coal. The teaching other countries is not entirely from altruism, it's an attempt to lower the coal usage by those countries . The below quote on teaching other countries about coal usage, is from Japan Times.
Every year, Japan invites about 60 engineers and managers from the coal industry of seven Asian nations -- China, Thailand, Indonesia, the Philippines, Vietnam, Malaysia and India -- to instruct them in the use of "clean coal technology," or CCT, which aims to improve the mineral's efficiency while reducing carbon dioxide emissions and pollution.