For anyone out there who is still skeptical of gasification
we offer you this: when one of the world’s largest energy from waste (EfW)
companies climbs on board the gasification train, you know the technology is
here to stay.
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| Courtesy: Covanta, REW Mag. |
Covanta Energy, owner and operator of more than 40 EfW
facilities in the U.S. and Europe announced plans to commercialize a
gasification unit it has been testing at the Covanta WBH site in Tulsa, Okla.
The unit has just completed a 10-month test run, processing 350 tons of
post-recycled municipal waste per day.
The adoption of gasification technology marks a significant
shift in Covanta’s stance on waste to energy. The company, which uses a mass
burn process at the majority of its facilities, has previously felt that
separation of materials and new technology such as gasification, was
unnecessary. Covanta has always been focused on producing the maximum amount of
reusable energy from its feedstock and has been quoted as saying the high cost
of sorting and recycling didn’t justify the difference it made:
“Within the [waste] hierarchy, the most debated and
potentially contentious boundary is that separation of waste for recycling and
recovery. It is accurate that as a general rule a high level of separation of
waste for recycling is desirable before the residues are diverted towards
recovery (generally, energy recovery). However, the costs of segregation and of
reprocessing tend to increase significantly as ever higher percentages are
achieved while quality, contamination issues, and the additional activities
required to achieve the higher percentages often reduce the environmental
benefit. Thus the marginal cost-benefits of very high levels of recycling may
not be favorable.”
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Covanta Energy Comments on: National Waste Policy Discussion Paper
Similarly, Covanta had previously said that gasification was
unnecessary due to the fact that large-scale EfW plants had developed
sophisticated back-end cleanup systems to keep hazardous gases from escaping
into the air. The changes in Covanta’s views on gasification signify an ongoing
revolution towards cleaner waste-to-energy processes.
Although Better BTU has not been able to find out specifics
on Covanta’s gasification system, it appears to be a partial-oxidation
technology that heats the MSW to high temperatures to create a syngas. The
syngas is then combusted and processed through an energy recovery system
followed by an emissions control system. The company has not released the
energy value of the syngas.
Covanta headquarters says the successful demonstration will
allow the company to market its CLEERGAS (Covanta Low Emissions Energy Recovery
Gasification System) to clients interested in the technology. Interestingly
enough, the company has not made announcements that it plans to use the
technology in any other existing or new facilities and President and CEO
Anthony J. Orlando had this to say on the Q2 2012 Results – Earnings Call:
“We believe this technology will enable us to be more
competitive on small units and that opens new markets. The level of interest
we’ve seen thus far is encouraging and we’re now exploring several
opportunities. We believe this technology will be an important part of our
long-term growth. But I don’t want to get anybody too excited, I’m talking
long-term. Development and implementation of energy from waste projects take
years.”
So while it is extremely encouraging to see the EfW giant
embracing gasification, it sounds like we still have a ways to go before it
replaces the traditional mass burn facility.
Further Reading:
Covanta
Energy Comments On National Waste Discussion Paper – Written by Covanta
for the Department of Environment, Community and Local Government (2012).
Covanta's
Gasification Technology Ready for Market - By Shawn Wright, Waste
& Recycling News (June 22, 2012).
Covanta
Holding's CEO Discusses Q2 2012 Results – Earnings Call Transcript
(July 19, 2012).
