98 7 0Download size Original (4536 x 3041) Large (1920 x 1287) Medium (1280 x 858) Small (640 x 429) Free stock photo of blue sky, building, business blue skybuildingbusinesschimneycloudsconstructionenergyenvironmentfacadefactoryfuelgrinderindustrial plantindustryleavesmachinemachinerymetalold buildingoutdoorspetroleumpipepollutionpowerproductionruinsrustysmokestainlesssteeltechnologytrees