Coal pollution mitigation Since air is mostly nitrogen, combustion of coal often leads to production of nitrogen oxides. Sulfur dioxide and nitrogen oxides are primary causes of acid rain. For many years--before greenhouse gasses were widely understood to be a threat-- it was thought that these by-products were the only drawback to using coal. These by-products are still a problem, but they have been greatly diminished in most advanced countries due to clean air regulations. It is possible to remove most of the sulfur dioxide (SO), nitrogen oxides (NO), and particulate matter (PM) emissions from the coal-burning process. For example, various techniques are
Lower sulfur oxides Lower sulfur oxides The lower sulfur oxides are a group of inorganic compounds with the formula SO, where m < 2n. These species are often unstable and thus rarely encountered in everyday life. They are significant intermediates in the combustion of elemental sulfur. Some well characterized examples include sulfur monoxide (SO), its dimer SO, and a series of cyclic sulfur oxides, SOx (x = 1, 2), based on cyclic S rings. Interest in the lower sulfur oxides has increased because of the need to understand terrestrial atmospheric sulfur pollution and the finding that the extraterrestrial atmospheres of Io, one of