The Seattle Biodiesel refinery started out in a little warehouse just a couple of years ago, making a few thousand gallons of eco-fuel a day for local buses.
Now it has mushroomed, attracting hundreds of millions of dollars in investment. The company is building the country's largest biodiesel plant, as well as three large plants around the world.
The growth is driven by government mandates: Washington state is requiring biodiesel in the state fuel supply, and other states may follow suit.
The company's phenomenal growth has a bit of a dot-com whiff about it, and some analysts worry that the biofuel business model might be too dependent on government largesse.
But the executives who run the company, which has renamed itself Imperium Renewables, say this boom is not going to go bust.