In modern plants the gases produced by combustion ( flue gases ) then pass through devices that remove particulates and oxides of sulfur and nitrogen before being exhausted via smokestacks into the air 现代的电厂中，燃烧产生的废气会再通过其他设备，去除硫与氮的颗粒及氧化物，最后才经由烟囱排入大气中。
