Sundrop Fuels, a startup based in Longmont, Colo., says it has found a
way to break into the notoriously difficult advanced biofuels business:
It’s putting its advanced technology on hold for now, and instead
building a plant for converting wood chips into gasoline. The plant will
use largely off-the-shelf technology, making it easier to get loans.
It’s also planning to reduce costs by using cheap natural gas to
generate the high temperatures needed in the plant, rather than using
concentrated sunlight, as it had originally planned.
Sundrop plans to start construction on the plant _ which will have a 50
million-gallon capacity _ later this year near Alexandria, La. It
recently announced a partnership with Uhde Corporation of America, a
partner of the German engineering firm ThyssenKrupp Uhde, to develop the
detailed engineering plans for the plant. Uhde will also supply a
gasifier that turns biomass into carbon monoxide and hydrogen, which can
be converted with the help of catalysts into a variety of fuels.
Sundrop had planned to use its own proprietary gasification technology,
which operates at high temperatures _ over 1,200 degrees Celsius, or
hundreds of degrees higher than some other gasifiers. The heat would be
generated by concentrating sunlight, rather than by burning the biomass,
the approach taken by other companies. Using heat from the sun would
increase the amount of biomass that ends up as fuel, reducing the cost
of transporting the bulky material. Operating at high temperatures would
avoid the production of tars that can gum up equipment and interfere
with later steps in the process.
Sundrop will continue to use high-temperature gasification to avoid tar
production, but it will use a design from ThyssenKrupp that requires the
introduction of oxygen. ThyssenKrupp’s technology is more expensive
than Sundrop’s gasification technology, says Wayne Simmons, Sundrop’s
CEO, but it’s commercially proven, which makes it easier for Sundrop to
get loans to build a plant. Sundrop plans to prove its own technology by
installing one of its gasifiers in the new plant, where it will be used
to make about 10 per cent of the plant’s output. Sundrop plans to use
its gasifier technology on a larger scale in future natural gas-powered
plants.
The decision to use natural gas rather than solar heat reduces costs: In
part due to recent low natural gas prices, it’s far cheaper to burn
that fuel than to build a field of mirrors to concentrate sunlight. The
natural gas, in addition to heating the gasifier, will also provide a
source of extra hydrogen. The ratio of hydrogen and carbon in biomass
isn’t the same as in gasoline _ the hydrogen from natural gas makes up
the difference, increasing the fuel yield from biomass. The other option
would be a reaction that uses carbon monoxide to produce hydrogen from
water _ but that would lower yields and force Sundrop to truck in more
biomass.
Switching to natural gas had another benefit. As with the decision to
use conventional gasification technology, it has helped Sundrop finance
its first plant. It attracted $155 million in funding from natural gas
producer Chesapeake Energy, which was seeking to fund technologies that
would increase demand for natural gas.
The use of natural gas means emissions have increased, however. When
Sundrop used solar heat, its gasoline resulted in 90 per cent lower
carbon dioxide emissions than conventional gasoline. But the company
says the emissions will still be 60 per cent lower than with
conventional gasoline.
The higher cost of the conventional gasifier will also make it difficult
to run the process profitably _ even with the benefit of cheap natural
gas. “It barely works,” Simmons says. “You wouldn’t build a whole lot of
these plants, because your equity return wouldn’t be good. You do make a
modest profit, but nothing like when you go to our (gasification)
technology at large scale. It’s more of a strategy to get into the
business.”
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