Sludge Watch ==> Ener Tech - Energy from sludge - Rialto

[Maureen Reilly]

Wednesday, March 14, 2007
New plan replaces sewage sludge fiasco
Officials embrace waste-to-energy plan for sewage sludge. It didn't work in 
Los Angeles 15 years ago, but this is different, they say.
By TERI SFORZA
The Orange County Register

In hindsight, it was little more than modern alchemy, "a technological crap 
game," a massive mistake that burned half a billion public dollars.

Convert sewage sludge into clean-burning energy.

In the 1980s and '90s, officials in Los Angeles spent some $500 million on 
two plants that were supposed to do exactly that. But what was elegant in 
theory turned out to be horrific in reality – abrasive sludge ate through 
valves, clogged pipes and erupted into flames so hot they took days to 
extinguish.

The city of Los Angeles' plant scrapped the technology at the heart of its 
waste-to-energy idea and went with something simpler. The Los Angeles County 
Sanitation District's plant never went online.

So it is with some déjà vu that officials are now touting the idea of 
converting sewage sludge to energy. This time, a private company is taking 
the financial risk of designing and building the plant, not taxpayers. Times 
– and technology – have changed, officials said. They believe the outcome 
will be very different now. But still, no one is completely sure – not even 
renewable energy company EnerTech Environmental, the one taking the risk.

"Can SlurryCarb successfully treat biosolids?" asked a report commissioned 
by EnerTech in 2005, examining the differences between the failed Los 
Angeles experiments and its patented SlurryCarb process.

"This question will not be answered definitively until the process is 
designed, constructed and operated."

The plant is now under construction in Rialto. It was originally scheduled 
to open this year, but is now expected to come online in 2008.

"The industry never forgets a failure," said Layne Baroldi of the Orange 
County Sanitation District.

The Orange County Sanitation District, the Sanitation Districts of Los 
Angeles County, and the cities of Riverside, San Bernardino and Rialto, have 
all signed contracts to send a collective 675 tons of sewage sludge a day to 
EnerTech's plant. Missing from this list is the city of Los Angeles, which 
was courted by EnerTech but didn't sign up.

EnerTech's "SlurryCarb" process will subject sludge to extreme heat and 
pressure. Cellular structures rupture, carbon dioxide gas splits off, water 
is easily removed, and what's left is essentially concentrated carbon. That 
stuff is dried and becomes what EnerTech calls "E-fuel," which will be sold 
to power cement kilns in place of coal.

SlurryCarb, EnerTech says, is different from the process behind the Los 
Angeles fiasco, which is called "Carver-Greenfield." Carver-Greenfield used 
oil to suspend solids as water is evaporated, which led to grave gumming up 
down the line; SlurryCarb does not. Carver-Greenfield used forced 
evaporation to remove water, which created yet other problems; SlurryCarb 
does not.

"Most of (Los Angeles') problems do not apply to the SlurryCarb process 
because the two processes are designed to do completely different things," 
says a 2005 report paid for by EnerTech, trying to assuage doubts.



Larry Stauch of Fullerton was surprised to hear that a project like this was 
going forward again. He worked for the Los Angeles County Sanitation 
Districts during the Carver-Greenfield troubles.

"The energy derived from human waste is small compared with the unbelievable 
amount of toxic emissions derived from the conversion process," Stauch said 
in an e-mail. "This type of facility trades one form of pollution with 
another. The industrial waste present in our wastewater contains heavy 
metals such as cyanide, chromium, zinc, and they do not break down in any 
heat. They just become airborne."

A permit has been issued for the Rialto plant by the South Coast Air Quality 
Management District, air emission controls have been built into the system, 
and heavy metals will not be released, said Baroldi of the Orange County 
Sanitation District.

"There are still unknowns about the SlurryCarb process," EnerTech's report 
says. "However … the Rialto project has a high likelihood of success."

The Orange County Sanitation District agrees.

"Although the SlurryCarb process is a new technology, much of the equipment 
used in the process is common in the biosolids industry," says a district 
report.

Even if the entire project went belly-up, venture capitalists and EnerTech 
would be left holding the bag, not taxpayers. "The only thing we would be 
out is time," Baroldi said.

The problem of what to do with sewage sludge is getting more problematic – 
and expensive. It used to be applied to the ground as fertilizer – a cheap 
option at $42 a ton – but that is being outlawed as farm counties grow 
concerned about possible health effects. Turning the gunk into fuel with 
EnerTech will cost the Orange County Sanitation District $72.40 a ton.

"It's cutting-edge, but we have to be innovative," Baroldi said.

http://www.ocregister.com/ocregister/homepage/abox/article_1620010.php