GREEN TECH
Fossil Fuels
reservoir is then sealed and a smaller tube provides a pathway for the oil to the surface . If the pressure is not high enough to push the oil to the surface , a gas lift or pump jack may be used . After the well is completed , an assembly of valves is affixed to the mouth to control pressure and flow . Petroleum is distilled at a refinery to produce gasoline , kerosene and other chemicals used in consumer products .
Coal represents about 20 percent of the energy resources used in the production of electricity in the U . S . After it is mined , coal must undergo processing prior to combustion . First , it is crushed in a feeder breaker . Large lumps travel on a conveyor and are broken up by a toothed drum . Next , the coal is crushed by a sizer
16 May 2015