blue
boiler
built structure
business
carbon dioxide
chemical
chemistry
chimney
climate change
corporate
corporation
effect
electricity
employment
energy
engineer
environment
equipment
factory
fog
fumes
furnace
gas
gasoline
heat
heat temperature
heavy
horizontal
industry
manufacture
manufacturing
merchandise
modern
nature
no people
oil
organization
petroleum
plant
pollution
power
process
quality
refinery
sky
stack
steam
steel
tower