colourful sky
blue
chemical
chemistry
chimney
construction
energy
engineer
engineering
environment
equipment
factory
fuel
gas
gasoline
heavy
industrial
industry
light
manufacturing
metal
night
oil
petrochemical
petrochemical plant
petroleum
pipe
pipeline
plant
pollutant
pollute
pollution
production
refine
refinement
refinery
sky
smoke
station
steam
storage
structure
sunset
sustainability
sustainable
tank
technology
tower
twilight
worker