South Korea Aims to Turn Human Waste to Fuel
August 31, 2012 4:50 PM
comment(s) - last by
(Source: Warner Bros Pictures)
We won't ask where the inspiration for this idea came to the research team
is a major issue for the massive metropolitan areas that are increasingly permeating our globe. Sludge, the leftovers of wastewater processing, is largely the remains of human fecal matter.
But some researchers are devising creative uses for the bowl movement brew. There's a researcher in Japan who's supposedly working to
turn sewer sludge into protein burgers
. And now a team of researchers in South Korea has suggested that producing biodiesel from sewage sludge may be cheaper than making it from spent food oil.
The study was led by Eilhann Kwon of the
Research Institute of Industrial Science and Technology
. He reasoned that sewage sludge was rich in lipid content, so why not try to turn it into biodiesel -- whose starting component is more typically the lipids found in various waste oils (think used french fry oil).
Sewage sludge lipids are produced when aerobic bacteria in sewer drainage convert pockets ("moieties") of methane (CH4) and carbon dioxide (CO2) into lipids, which are then converted to energy. Some of the lipids accumulate in the bacterial bodies which litter the drainage, hence the drainage can become relatively lipid rich.
Using n-hexane Professor Kwon extracted these lipids from dried sewage pellets. The team found that sewage has 2,200 times more lipid per gram than soybeans -- which are considered a fairly "oily" crop. And extracting those lipids cost a mere $0.03 USD per liter, versus $0.80 per liter of soy oil.
Sewage often has thousands of times the amount of lipids per gram as soybean oil and can be produced at a fraction of the cost. [Image Source: ThinkSoy]
So why hasn't this been done before? Well it turns out fatty acid impurities also lurk in sewage, and foul the biodiesel catalytic conversion process, which involves combining the lipids with methanol.
To solve that problem the team came up with a non-catalytic process that uses heat, rather than a catalyst, to drive the reaction to completion. The new process also increases the surface area involved in the reaction to further accelerate the reaction. To do this it traps the reaction ingredients in a porous material -- activated alumina.
In a test, with a reactor heated to 380 °C, with excess carbon dioxide present, a 98 percent conversion rate was achieved.
In lab tests, 98 percent of sewage lipids were converted to biodiesel using the new process.
[Image Source: ACS]
Professor Kwon hopes to move aggressively to offer the new waste salvage technology to sewage processing plants. To do that a desiccation (drying) area would be needed, and extraction facilities would need to be added. But Professor Kwon believes these additions could be paid off in a matter of years, yielding both a profit and environmental gains. He comments, "Waste is not simply waste—it can be converted into useful resources like biodiesel."
The new method has been
[abstract] in the peer-reviewed journal
Environmental Science Technology
Mississippi State University
praised the work in
Chemical Engineering News
, commenting that the results were "very encouraging" while cautioning that quality of waste varies from location to location and amongs given batches at a particular location.
Chemical Engineering News
This article is over a month old, voting and posting comments is disabled
RE: The Smell
9/2/2012 3:50:17 PM
A fact: exhaust of a vehicle running on processed cooking oil smells like a huge fryer (think: fries or donuts). Older diesel cars (such as VW Golf from the 80s/90s with their atmospheric diesel engines that came before the introduction of TDI engines) run on that stuff and it doesn't take much in the way of chemical processing to make it work, no matter how foul the oil you're starting with.
A question: what does the exhaust of a vehicle running on human poop smell like ?
RE: The Smell
9/2/2012 5:47:39 PM
Why don't you pinch one off into a toaster, and tell us all!
"We are going to continue to work with them to make sure they understand the reality of the Internet. A lot of these people don't have Ph.Ds, and they don't have a degree in computer science." -- RIM co-CEO Michael Lazaridis
Bill Gates Looks to Flush Old Toilet Design, Develop More Efficient Models
August 15, 2012, 12:40 PM
Japanese Make "Delicious", Nourishing Steaks From Human Feces
June 17, 2011, 10:51 AM
Creationists are Mad About Google Doodle Depicting Evolution
November 24, 2015, 8:48 PM
DHS and TSA: Whoops, We Missed That 73 Airport Employees May be Terrorists
November 19, 2015, 2:16 PM
Star Wars Spinoff Film "Rogue One", Theme Park Attractions Announced
August 17, 2015, 12:20 PM
SpaceX Falcon 9's Seventh Supply Mission to ISS Ends w/ Fiery Stage 1 Explosion
June 28, 2015, 1:10 PM
Cool Science Video: Glowing Millipede Prowls the Nevada Desert
May 18, 2015, 12:00 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2016 DailyTech LLC. -
Terms, Conditions & Privacy Information