blue
chemical
chemistry
chimney
construction
economy
energy
engineer
engineering
environment
equipment
factory
fuel
gas
gasoline
heavy
industrial
industry
light
manufacturing
modern
nature
oil
petrochemical
petroleum
pipe
pipeline
plant
pollutant
pollute
pollution
production
refine
refinery
river
sky
smoke
steam
storage
structure
sustainability
sustainable
tank
technology
tower
twilight
water
worker