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
Nitrogen halogenating agents. Nitrogen forms nine molecular oxides, some of which were the first gases to be identified: NO (nitrous oxide), NO (nitric oxide), NO (dinitrogen trioxide), NO (nitrogen dioxide), NO (dinitrogen tetroxide), NO (dinitrogen pentoxide), NO (nitrosylazide), and N(NO) (trinitramide). All are thermally unstable towards decomposition to their elements. One other possible oxide that has not yet been synthesised is oxatetrazole (NO), an aromatic ring. Nitrous oxide (NO), better known as laughing gas, is made by thermal decomposition of molten ammonium nitrate at 250 °C. This is a redox reaction and thus nitric oxide and nitrogen are also produced as