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Biodiesel From Sewage Sludge
MTorrice writes "Scientists have developed a way to convert lipids from sewage sludge into biodiesel. The low cost and high yield of the sludge process may make it economically feasible as a source of biofuel, the researchers say. Today, biofuel producers use lipids in vegetable oils to derive biodiesel, a mixture of fatty-acid-like molecules. Biodiesel is compatible with existing diesel engines, burns with less pollution than petroleum-derived diesel does, and comes from renewable resources. But current biodiesel feedstocks are expensive, limiting the fuel's widespread use. The researchers from South Korea found that sewage sludge, the semisolid material left over from wastewater treatment, can yield 2,200 times more lipids than soybeans and costs 96% less to process. To turn the sludge lipids into biodiesel, the researchers heated them with methanol."
Sewage: the new bitcoin?
Sheesh, evil *and* a jerk. -- Jade
They say that fryer oil based bio diesel smells vaguely of fries. This slightly concerns me.. as sewage based bio diesel would smell like...
I've never taken my wife seriously when she's said my poo smells so bad I could use it to fuel my truck for the life of the vehicle.
Chewbacon
The Bible is like Wikipedia: written by a bunch of people and verifiable by questionable sources.
free liposuction for biodiesel production. People could live on fat farms, where they are paid to be fat, in exchange for all of their 'lipids'. free doritos and fox news for all.
read: soylent green won't be food, it'll be fuel.
Now we just need a car design that has a toilet you can hook your butt to directly so you can eat and poop while driving to keep fueling it.
Cueing bad Matrix references in 3... 2... 1...
Think of all the money we've been flushing down the toilet!!!
Emission production as you state it is only a problem on a local level where the emissions are most concentrated (dense cities). Even electric cars will have emissions (either in production or at whatever plant is making the electricity for it). It's the part about digging up materials which have been locked underground for millions of years and then releasing those emissions into the atmosphere that is the global problem. If all of the energy and consumables your vehicle used during it's entire lifetime (including manufacture) were harvested from plants or otherwise scraped off of the surface of the biosphere instead of from within the ground you would essentially be close to net-neutral impact on the planet as far as emissions are concerned (not that there is no impact, it would just be ridiculously low impact).
Biodiesel (as usable in my VW Jetta) is only a little less efficient than petrol / oil based diesel. Mileage is about 5mpg lower or so, but you have to make sure the biodiesel is clean of other contaminants which can be a bit laborious depending on the original source. Of course most people I am aware of will typically use an 85/15 blend for better performance (15% regular diesel).
As far as emissions go, I don't think it's too much different but I don't know much about that. I guess it would entirely depend on how "clean" and viable the input is.
In any case, if we can turn something which truly does not have a better use other than to be cleaned (at great expense) and sent back into the biome into a usable fuel at less expense I fully support research into it. It seems to be much smarter than ethanol where suddenly the price of fuel becomes linked to the price of food. We honestly don't currently have a better use for human sewage anyways considering it is not considered fit for fertilizer either. Besides, if this comes to America just think of how much fatty acids are already present in the McSewage, or how we could just re-introduce Olean oil if we needed to increase production (how's that for a disgusting thought?).
- Toast
To expand on this, in new TDI's from Audi/VW at certain intervals raw diesel is injected into the cylinders post burn to heat up the particulate filter and burn off collected carbon. Because of this the raw diesel fuel mixes a little with the oil. For petroleum based fuels this is not a problem as the synthetic oil is designed to allow this to happen. Unfortunately biodiesel is a really great engine cleanser. The problem is that when biodiesel above 5-10% mixes with the synthetic oil the oil is diluted and loses its ability to adhere to the cylinder wall and prevent friction. I think most people understand the basic concept of running an engine without oil. My understanding is that a person could run up to 20% biodiesel if they are willing to make very frequent oil changes, say every 5k miles. But at ~$60 a change it may seem pricey for you.
There is or can be built a machine that can simulate any physical object. -Church-Turing principle
The better comparison might be between the emissions that would normally be produced by allowing the raw material to decompose naturally and the emissions from turning it into biodiesel and burning it. They would be different gasses, so the comparison would need to account for the different greenhouse effects. I understand that methane is one of the worse ones, so your emissions on this type of biodiesel might come out negative.
Yeah, that's basically the way all biodiesel is made... But the problem with biodiesel isn't just the price of feedstock (used fryer oil is cheap enough already!), it's the price of removing stuff from the feedstock that would make the biodiesel of unacceptably low quality (free fatty acids, BCBs).
xkcd is not in the sudoers file. This incident will be reported.
It seems to be an issue with common-rail diesels. The Bosch pumps fitted to old VWs and PSA XUD engines aren't bothered in the least, but XUDs with Lucas pumps won't last the pace. Anything with a common-rail system has big warnings in the manual not to use it with biodiesel, which seems like a step backwards.
It annoys me slightly that the heavy, lumbering, clattery 2.5 litre 200bhp turbodiesel getting 40mpg in my old CX is cleaner than the 50mpg 1600cc engine in my van...
Regarding Emissions:
Biodiesel is much better for the air. While it certainly does produce CO2 in nearly the same amounts per unit burned, it is unlikely to contain sulfur in measurable amounts. How much sulfur is in deep fryer oil, or sewage? Practically none, since it's poisonous. People don't eat it in more than trace amounts.
So while Biodiesel is still not great for greenhouse emissions (unless it's balanced. Plant a tree dammit!), it's great for the breathing air of critters like us, compared to petroleum derived diesel. And if you clean it so it burns better in your engine, it's going to be much lower in particulate emissions as well.
If sewage derived biodiesel is scalable, (and it looks like it might be), this could mean the end to all the shit we put up with going to war for petroleum.
Hectice, baby, Mercator says hello to you
What if biodiesel users implemented a more viscous oil? Would that help? I'm honestly curious.
Wouldn't a higher viscosity oil dilute less quickly, making it last longer? Or would it still cause problems by not lubricating the engine enough, and letting heat build up from friction anyway, since the oil doesn't move as quickly?
Hectice, baby, Mercator says hello to you
Biogas from waste water treatment plants (WWTPs) do contain sulfur, and the amount can vary a lot. Basically it depends on type of water treatment plant and the chemical (if it uses chemicals) used. In some cases reports have indicated more than 1000 ppm of H2S in biogas, but generally it's approximately 0-100 ppm.
The sulphur does come from waste and some from water as well. According to Wikipedia, human body (70kg) contains approximately 140g of sulphur. It's necessary component for living cells. So sulphur as itself is not that poisonous. LD50 value for pure sulphur is ~5g/kg. H2S is more poisonous (>100ppm is immediately dangerous, and 10 ppm is recommended limit for 10 min exposure), and active reducing bacteria tend to reduce the organic sulphur into H2S in biological plants.
And obviously the location determines the amount of sulphur in waste water, whether it's mostly municipal waste or chemical process waste water.
I don't know how much of this sulphur would end up in the lipids, though, but generally stating that sulphur is poisonous and waste water does not contain it, is just wrong.
....If you want to make biofuels on a truly huge scale, there's only one source that actually makes sense: oil-laden algae.
Since some forms of oil-laden algae can grow in seawater, that right there means anywhere near an ocean the algae can be grown on a very large scale without the enormous expense of finding a source of fresh water. And the waste from processing oil-laden algae into biodiesel fuel can be processed further into either ethanol or turned into agricultural fertilizer.
Except, methane is burned in the production of the biodiesel. The combustion products of methane end up being CO2 and Water. The CO2 can be scrubbed and sequestered in the operation.
If the sewage were not being processed for biodiesel, then it would have given off methane into the atmosphere during natural decomposition, wouldn't it? So this processing prevents some amount methane from being emitted (and possibly uses some more methane from another source; I didn't see that mentioned in the article, but there seems to be a lot of methanol involved, so I guess that might use methane during its production, although I don't know what happens to it after it's used here.) The upshot is that CO2 is produced (when the diesel is produced, and again when it's used), but a bunch of the more dangerous CH4 is avoided or destroyed, so might that not work out as a net good?
The issue I see is that newer VW TDIs (with the common rail system) is not designed to run on anything higher than B5 (95 Diesel/5 Bio). With my 2012 Jetta, if I use anything higher, they can void my warranty, and they are able to tell. Which sucks cause the station right near me that does Diesel does anywhere from B1 to B11, no notice as to what it is at that time. The problem here is the point in which biodiesel combusts, as compared to straight diesel. To be "clean burning", which VW Diesels are, they do a direct injection of diesel into the exhaust system to burn off the soot and other impurities that are/were common with diesel engines. Biodiesel doesnt ignite the same, leaving the impurities/soot, causing it to clog part of the exhaust system up, requiring expensive replacements.
This is to say, annoying, at the least. Now, I've heard of people having good luck with mod kits adding a second (heated) tank to use with filtered waste vegetable oil, with a cutover switch in the cabin. Start on diesel, switch over to WVO, then switch back later, but those were with pre-2010 VW Diesels.
OMG... I have a sig?
They used to claim that the increase lubrication caused greater fuel efficiency in the bio form. Diesel is a lot like gas where it is formulated in different types in different parts of the country at different times of the year. This claim may be just something that is regional or perhaps only applicable during certain types of the year.
As for restaurants, Every one I worked at sold the waste oil to make soap and other supplies from. At a family style restaurant I was part owner of once, we got something like $100-$150 a month from our waste oil and they came and picked it up. This was 20 years ago but I was really surprised to find stories of people just getting the waste oil from restaurants. They must have stopped using it for those purposes or maybe the owners didn't know of it.