Quite a lot of the energy that goes in to cremating a body presumably goes just to evaporate the water that is 80+% of its mass.
So, remove the water first. Place the body in a pressure tank. Attach a couple of rotary vacuum pumps. Place them under the surface on which the body rests so that the waste heat from the motors warms the body by conduction and promotes evaporation. Pump the chamber down progressively to about 1 millibar. Leave it like this until the mass has decreased by an acceptable amount. Then remove it and cremate it.-- 8th of 7, Jun 26 2002 Freeze-dry bodies http://www.thenaked...hows/2001.10.07.htmsee under A Greener Funeral [FarmerJohn, Jun 26 2002, last modified Oct 21 2004] So instead of using energy to remove water during cremation, you use energy to remove water before cremation.-- angel, Jun 26 2002 If it's energy saving and environmentalism you're after just go for the solar powered crematorium (with loads of big sun-tracking mirrors).
"Father, could you keep the eulogy doing for another ten minutes -- the Sun's just gone behind a cloud."-- st3f, Jun 26 2002 Angel: Yes, but you use less energy overall. The exhaust from a crematorium retort stack is pretty damned hot. The ehaust from the vacuum pumps will be at ambient. And the heat from the pump motors goes back into the chamber; additional heat will be absorbed from the environment around the chamber. I'll do some math on the thermodynamics and get back to you.-- 8th of 7, Jun 26 2002 Don't trouble your elf, that's only one objection. Many mourners want a last look at dear old Whatever just before he slips behind the curtain. A shrivelled up raisin of a granny might not be so comforting.-- angel, Jun 26 2002 Baked as frozen in link. Costs as much, no toxicity and can be spread on a forest floor.-- FarmerJohn, Jun 26 2002 FarmerJohn: Didn't show up on my google search - wrong criteria I guess. But equally acceptable.
We suppose YOU would prefer to put the beloved on the top of a lighting rod, then leave some minion to mop up the gristly lumps afterwards ? (lapses into bitter, resentful muttering and offensive gestures)
Blissmiss: Et tu, Brute .... ?
Angel: The drying process occurs between the curtains closing and the body going into the retort.-- 8th of 7, Jun 26 2002 Logicaly, the more 'spiritual' a person is, the less I would expect them to be concerned by what happens to 'mortal remains'. Pets are sometimes 'preserved' by storing in a freezer, bagged with silica gel dessicant. This is a pretty low-power way to dry, but you have to heat the gel to recycle it.-- pfperry, Jun 26 2002 Even better, do what they've already done somewhere- I will try to find a link. They tried to use the heat from crematoriums to heat the homes in the country. Maybe we could use crematoriums as one of our next sources of energy.
"Energy: It's People!"-- polartomato, Jun 27 2002 Polartomato: Ah, good, another Soylent Green fan !!-- 8th of 7, Jun 27 2002 If energy savings are desired, it should be possible to add a condenser to the exhaust of a cremator; such a device should be able to recover much of the latent heat of water vapor.
BTW, producing a vacuum requires a lot of energy; if a person contains 72kg of water, that's 4,000 moles of water, or about 90,000 liters of water vapor. Freeze drying such person's body would require pumping 90,000 liters of water vapor against a pressure differential of almost one atmosphere.
Any physicists care to complete the computations?-- supercat, Jun 28 2002 Slice me open, throw in some oak seeds, and cover me with mulch. Back to nature!-- protean, Jun 28 2002 I don't think we can apply too much logic to the rigmarole of cremation. [I know that sounds like a cop out]
If the priority was to get rid of the body as efficiently as possible, we'd give it concrete shoes and chuck it into a river.
I reckon the priority is for the family to say goodbye to a loved one...and they are paying for it too. Give a family a choice...burn the body or dessicate it into what may resemble a shrivelled prune and then burn it.
I suppose the idea does have merit though... you could use the 'reclaimed' water as a new soft drink. Calling it 'Coke' would infringe copyright and be an incredibly tenous link to combustion.-- Jinbish, Jun 28 2002 Quite apart from the 'Eeew' factor.-- angel, Jun 28 2002 Crema Soda-- thumbwax, Jun 30 2002 Would you like cremate in your freeze-dried coffeen, sir?-- FarmerJohn, Jun 30 2002 Crema Soda... So gross. Could we flavor it? Like Orange Crema Soda? Just wait till I tell my Grandma what we're doing with her remains when she dies!-- BakedRiemannZeta, Mar 17 2010 let yourself be eaten by vultures and other birds, its good for them and does 0 harm.-- WcW, Mar 17 2010 Depends on why you died and what drugs you took beforehand, particularly diclofenac.-- nineteenthly, Mar 17 2010 cut into thin slices and toss onto the dehydrator (big fan). Then incinerate the stips of what can only be described as beef jerky. Uses less power than creating an insane vacuum, which might not necessarily seperate the fluid.-- AutoMcDonough, Mar 17 2010 random, halfbakery