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Human waste proposed as source of natural gas
Scott Simpson, Vancouver Sun
Published: Tuesday, July 22, 2008

Terasen Gas customers on the North Shore could soon be firing up 
their furnaces and hot-water heaters with natural gas collected as 
a byproduct in the processing of human waste.

A $1.1-million project involving Terasen, Metro Vancouver and 
QuestAir Technologies proposes to capture and purify "biogas" from 
operations at the Lions Gate sewage treatment plant and pump it 
into a nearby Terasen distribution pipe for use by the gas 
utility's customers.

It will be the first time in B.C. that energy from human waste is 
captured and used in this fashion, and it's fairly novel on a 
global scale as well -- although processes using gas from 
landfills and agricultural waste are well established.

Last week, the project received a $366,000 grant from British 
Columbia's Innovative Clean Energy (ICE) fund.

As with natural gas that is conventionally pumped from underground 
deposits, the gas produced at Lions Gate will be almost pure 
methane. It's an odourless, clean-burning heat energy source.

Gas producers typically add trace amounts of another gas, 
mercaptan, which smells like rotten eggs, so that it can be 
detected in the event of a leak.

The Lions Gate gas is produced in the "digestion" of sewage, a 
mechanical process that separates solid from liquid waste at the 
regional treatment facility in West Vancouver.

Some of the gas produced in this process is already being burned 
as heat to support waste digestion, but Lions Gate produces more 
than it can use.

The excess gas has traditionally been flared, or burned off, into 
the atmosphere through an open flame.

"As times change and technologies change, no one wants to be 
flaring gas," said Stan Woods, a senior engineer with Metro 
Vancouver. "So there is a real opportunity, and it worked out well 
for Terasen in the sense that there is a gas pipeline nearby."

The gas will be processed to remove impurities using technology 
from Burnaby-based QuestAir, and pressurized for insertion into a 
nearby Terasen gas-delivery pipe.

Terasen expects the project will yield enough gas to meet the 
energy demands of 100 homes.

The Lions Gate project could be in operation as early as July 2009 
and Terasen hopes to learn enough to develop a larger-scale 
operation in future, such as harvesting methane from agriculture 
waste.

Terasen communications manager Joyce Wagenaar said the project 
will last at least 10 years and represents "a significant 
demonstration and learning opportunity" for the gas utility.

"We feel that biogas has the potential to be a cost-effective, 
clean energy source and we need to explore that," Wagenaar said in 
an interview.

"Metro Vancouver has other [waste water treatment] plants so if 
this pilot is successful there is potential there."

Wagenaar said Terasen is particularly interested in a recent study 
by BC BioProducts Association, which identified substantial 
potential for biogas produced from agricultural waste in the 
Fraser Valley.

"That could produce enough gas to serve 25,000 homes, so we are 
really looking at biogas, and depending on the success of this 
project, would explore other opportunities across the province."

http://www.canada.com/vancouversun/story.html?id=47e363c0-1b3b-4a5b-81b5-ae45ea0a9853

--
Kyle J. Fricker
Chemical Engineering
University of Florida