Naked Science Forum
General Discussion & Feedback => Just Chat! => Topic started by: scientizscht on 01/07/2018 12:32:42
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Hi!
In the UK, more than 1600 people die every day. Since human body is 70% water, and average weight 75kg, we have 35 tonnes of biomass every day.
What energy can we produce from that and how much?
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Hi!
In the UK, more than 1600 people die every day. Since human body is 70% water, and average weight 75kg, we have 35 tonnes of biomass every day.
What energy can we produce from that and how much?
E=mc² ?
I would definitely use dead bodies for fuel if there was a need to.
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The big problem would be collecting from all over the country.
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The big problem would be collecting from all over the country.
Not with a refrigeration special.
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No different than cremation right ?
Waste not , want not.
Good for the environment I imagine also ?
It is not terrible, not bad, not unholy, the pitch is:
In you we live on...
Sign up people , don't be shy now, lets all do our bit for humanity, there will be some good come out of even the bad people.
Look Arnie did it ....if its good enough for Arnie....well...
Obviously you will be dead so won't know anything about it, your soul will be long gone.
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I want to post this idea to a Sustainability competition, do you think I can win?
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I want to post this idea to a Sustainability competition, do you think I can win?
Depends how it is wrote up, I suggested this before , but that is ok , enter you never know.
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You would need to start with something like:
This proposal is a revolutionary idea that at first may sound distasteful to some, but objectively it is an idea with a certainty of success , that an avoidance of the depletion of natural resources in order to maintain an ecological balance will be met.
As we know with an ever increasing world population and environment change , the demands on energy are becoming greater by the year, these demands getting harder to sustain and our supplies of fuel will eventually run out, setting us back into the stone ages unless a viable solution is found.
Thus ladies and gentlemen we propose the seemingly insane suggestion of using deceased human corpse's as a sustainable fuel . A human body contains xx amount of energy and each day in the UK alone , xx kg in mass becomes available by means of death .
Death is unpreventable and often at a funeral corpse's are cremated which in essence is no different than the proposed notion.
We understand the moral issues and religious issues that may be raised in concerns to this notion, but the alternatives are looking doubtful for any near future . We predict that in the future if our fuel runs out, society and civil rest will totally collapse . Additionally our environment will be too harsh to survive in and the eventuality, the extinction of the human race.
Something like that anyway .....
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To do a quick calculation, I'll use this estimate of 110,000 kilocalories for an average human: https://www.quora.com/How-many-calories-are-in-a-human-body
Admittedly, this is probably a slight underestimate, since indigestible things like hair and fingernails could potentially be burned to release some energy as well. I'll ignore that for the time being. 110,000 kilocalories times 1,600 people is 176,000,000 kilocalories. There are 4,184 joules in a kilocalorie, so 176,000,000 kilocalories times 4,184 is 736,384,000,000 joules per day. There are 86,400 seconds in a day, so 736,384,000,000 joules divided by 86,400 is 8,522,962.96296 joules per second (about 8.5 megawatts).
That's not a lot of energy compared with many power stations, which usually run from hundreds of megawatts to multiple gigawatts. It is more, however, than a typical wave power plant and a few tidal power plants. See this list: https://en.wikipedia.org/wiki/List_of_largest_power_stations
Like Bored Chemist says, gathering the bodies would pose an important obstacle. Delivering bodies from around the country to a power station will require burning large amounts of petroleum products in order to power the vehicles (unless you used solar-powered cars or something, which have their own issues). If you burn more energy transporting the bodies than you get from burning the bodies, that would render the point moot. I may look into calculating that fuel burn later.
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Like Bored Chemist says, gathering the bodies would pose an important obstacle. Delivering bodies from around the country to a power station will require burning large amounts of petroleum products in order to power the vehicles
The mortuaries could be next to the rail tracks, a night train could pull up outside from a siding .
A funeral service would be done differently .
Funeral cost cutter for sure .
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To do a quick calculation, I'll use this estimate of 110,000 kilocalories for an average human: https://www.quora.com/How-many-calories-are-in-a-human-body
Admittedly, this is probably a slight underestimate, since indigestible things like hair and fingernails could potentially be burned to release some energy as well. I'll ignore that for the time being. 110,000 kilocalories times 1,600 people is 176,000,000 kilocalories. There are 4,184 joules in a kilocalorie, so 176,000,000 kilocalories times 4,184 is 736,384,000,000 joules per day. There are 86,400 seconds in a day, so 736,384,000,000 joules divided by 86,400 is 8,522,962.96296 joules per second (about 8.5 megawatts).
That's not a lot of energy compared with many power stations, which usually run from hundreds of megawatts to multiple gigawatts. It is more, however, than a typical wave power plant and a few tidal power plants. See this list: https://en.wikipedia.org/wiki/List_of_largest_power_stations
Like Bored Chemist says, gathering the bodies would pose an important obstacle. Delivering bodies from around the country to a power station will require burning large amounts of petroleum products in order to power the vehicles (unless you used solar-powered cars or something, which have their own issues). If you burn more energy transporting the bodies than you get from burning the bodies, that would render the point moot. I may look into calculating that fuel burn later.
I was thinking not to burn the corpses but to feed bacteria or something to produce biofuel. 35 tonnes of bacteria food every day would sustain a huge bioreactor.
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I was thinking not to burn the corpses but to feed bacteria or something to produce biofuel. 35 tonnes of bacteria food every day would sustain a huge bioreactor.
Then the total energy yielded will be less than in my original calculation. Every time you add an extra step in converting energy from one form to another, you end up with inevitable waste heat. There are also combustible substances in the human body that can't be converted into substances like ethanol, so that's another source of energy loss.
An average estimate for the human body would be a content of 5% carbohydrates: http://www.volac.com/lifestyle-ingredients/why-whey/market-sectors/protein-and-the-human-body . If the total mass of the corpses is 120,000 kilograms, then the amount of carbohydrates would be 6,000 kilograms. During typical fermentation processes, you get about 0.511 grams of ethanol per gram of glucose. That's 3,066 kilograms of ethanol (about 1,026.5 gallons). Since the specific energy of ethanol is 30 megajoules per kilogram, that is 91,980,000,000 joules per day of ethanol.
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35000 kg per day sounds like a big number, but it really isn't. A small coal-fired power plant burns about that much coal per minute, and might power a mid-sized town. Collecting bodies from across the country to add a minute of power for a few villages is not a good idea to pursue, and won't win any prizes.
And as pointed out, by Kryptid, turning it into biofuel will only detract from the energy. (The bacteria require energy to live).
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Now for an attempt at a transportation energy calculation. This is somewhat difficult to do because of the irregular shape of Great Britain and the fact that the population is not uniformly distributed throughout it. Nevertheless, I'll try to make some simplifying assumptions to get at least a rough handle on how far transport vehicles would have to drive on average.
The north-south length of Great Britain is 967 kilometers and its width is 437 kilometers: https://www.worldatlas.com/webimage/countrys/europe/unitedkingdom/uklandst.htm . We'll assume the collection facility is roughly in the center of the island in order minimize the average travel distances. If we assume that just as many people die far from the facility as die close to it, we can say that the average north-south distance from the facility traveled is half the length of the island (483.5 kilometers) and half the width of the island (218.5 kilometers). We can average these two numbers to get a rough average distance traveled of 351 kilometers.
The next part considers fuel efficiency. If we are using something akin to tractor trailers to haul around these bodies, then you could get up to about 4.46 kilometers per liter of fuel: https://news.nationalgeographic.com/news/energy/2011/09/110923-fuel-economy-for-trucks/
351 kilometers divided by 4.46 kilometers per liter is 78.7 liters of fuel used. Diesel fuel has an energy density ranging from 34 to 39.6 megajoules per liter: https://hypertextbook.com/facts/2006/TatyanaNektalova.shtml . That represents a total energy expenditure of 2,675,800,000 - 3,116,520,000 joules per day. That's about 3% of the expected energy from the ethanol produced at the bioreactor (though given the uncertainties in my calculations, I'd guess a range of anywhere from 1-10% would represent the real value). So that isn't necessarily a deal breaker, but when the amount of energy you are getting is already pretty small, it does warrant some consideration.
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After reading through the thread and then also considering salary expenditure, perhaps it is not such a good idea to put into practice, but nevertheless it was an interesting idea.