Sludge Watch ==> Akron Ohio - sludge plant - energy from bacteria

[Maureen Reilly]

http://www.ohio.com/mld/beaconjournal/17257774.htm

Power station to ease energy troubles
Akron sludge plant will be first in nation to create electricity with aid of 
bacteria
By Bob Downing
Beacon Journal staff writer


   * Innovation in power generation

By late this year, Akron hopes to be turning sewage sludge into electricity.

The city and KB Compost Services Inc. began construction in September of a 
$7 million plant -- the first of its kind in the United States -- that will 
rely on bacteria to feed on sludge to produce a gas that can power an 
electric generator.

The new facility is similar to about 200 plants in Europe and Asia developed 
by a German company, Schmack Biogas AG.

The system relies on bacteria that do not need oxygen -- a process known as 
anaerobic digestion. Instead, the bacteria cause the sewage sludge to 
ferment.

The bacteria multiply, consume part of the sludge and produce a methane-rich 
burnable gas called biogas, said Akron spokesman Brian Gresser and Annette 
Berger, vice president of operations at KB Compost Services.

The biogas will be 60 percent methane, 35 percent carbon dioxide and 5 
percent other gases. In comparison, natural gas is 99 percent methane.

Gresser said the process will help reduce the city's escalating costs in 
handling sewage waste from Akron and its suburbs. Electricity produced by 
the plant is expected to reduce energy costs, and if successful, the process 
could replace the aging compost facility.

The spark for the innovative plant was a trade trip that Akron Mayor Don 
Plusquellic made to Germany four years ago. He inspected a similar facility 
near Zurich, Switzerland, and brought the idea back to Akron.

The plant, on city land next to the Cuyahoga River, will be owned by the 
city and operated by KB Compost Services, a company based in the Cleveland 
suburb of Independence.

Company formed

KB Compost Services has partnered with Schmack Biogas AG to form a new 
company, Schmack Bio-Energy LLC headed by Mel Kurtz in Independence, to 
promote the German technology in the United States.

Schmack, based in Schwandorf, Germany, was founded in 1995 by three brothers 
with dairy cattle and lots of manure. The company has become a key player in 
the booming biogas industry that is just taking off in this country.

The Akron project has quietly been under development for three years. It won 
Ohio Environmental Protection Agency approval in late 2005.

Akron is investing $835,000 in the plant, Gresser said.

That money is coming from the $250,000 a year the city now gets from KB 
Compost Services in rebates for the sale of soil-additive materials from the 
city-owned composting plant that processes sewage solids, he said.

The contract requires the partners to decide after 18 months of operation 
whether the process is working satisfactorily. If it is, Akron and KB 
Compost Services will negotiate a new contract and look into expansion. If 
not, the city has the right to walk away.

The plant is expected to be a showcase for KB Compost Services and its 
partnership with the German company and help demonstrate that that the 
technology works.

Expansions would allow the city to replace the sometimes- stinky city-owned 
composting plant, which handles 1.2 million gallons of sludge per week, said 
Gresser, who oversees the city's sewage and composting plants.

The new facility will consume about 20 to 30 percent of the 335 kilowatts 
expected to be generated by the new process, and the remainder will help 
power other operations at the sewage treatment plant -- although the city 
could opt to sell the gas rather than produce electricity.

The city is hoping to offset some of its $1.35 million in annual electricity 
costs for sewage treatment.

The initial phase would produce enough electricity to power about 200 homes. 
The entire sewage treatment plant requires about 2.8 megawatts, or enough to 
power 1,700 houses.

Biogas plants are common in Europe where Plusquellic saw the Swiss plant on 
a side trip before the Hanover Trade Fair.

``We already had most of the infrastructure to make it work at our 
composting facility, so it wasn't a stretch logistically,'' Plusquellic 
said. ``I always find opportunities to learn from others about how they do 
what they do. And in this case, getting the most out of materials we'd 
otherwise discard has wide-ranging benefits for us.''

The new plant is designed to handle one third of the sludge that now goes 
through the compost plant, or about 5,000 tons a year.

Aging plant

With expansions, the plant could erase the need for the composting plant, an 
operation that costs Akron $6.2 million a year, Gresser said.

The composting plant has served Akron well for 20 years, but the plant is 
aging and odors are still an occasional problem, he said.

The new plant is ``the next step'' and will help Akron be more self-reliant, 
he said.

The process itself could also handle other wastes, not just sewage sludge. 
That includes animal manure and wastes from the beverage industry, fruits 
and vegetables, meatpacking, slaughterhouses, dairies, certain factories, 
breweries and distilleries. It cannot handle fiber-rich wastes like wood or 
leaves.

The new process will reduce the volume of the waste by 50 percent. What 
remains will have little smell but must be pasteurized to comply with Ohio 
EPA regulations, Berger said. The solids can then be added to blended soils, 
she said.

The new largely automated plant will not require additional manpower. It 
will be run by KB Compost Services' staff of 23 that now run the composting 
plant.

Before the compost plant opened in 1986, Akron incinerated its sewage 
sludge. That ended in 1993



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