09 March 2011

Ecological burial: freeze-drying and composting

I first wrote about promession in this blog two years ago.  This week PhysOrg provides some updated information.
The first part of the ecological burial method involves removing the water that makes up 70% of the human body. To do this, the company freeze-dries the corpse in liquid nitrogen within a week and a half after death. The corpse is first frozen to -18°C (0°F) and then submerged in liquid nitrogen. Next, sound waves at a specific amplitude vibrate the brittle corpse, transforming it into an organic white powder. The powder is sent through a vacuum chamber that evaporates the water, greatly decreasing the corpse’s mass...

At this point, the organic powder is hygienic and odorless, and the remains can either be cremated or buried. Since the powder will not decompose if kept dry, there is no hurry for a burial. At the time of burial, the remains are laid in a coffin made of a biodegradable material such as corn starch and placed in a shallow grave. Depending on the wishes of the next of kin, a bush or tree can be planted above the coffin. Within 6-12 months, both the coffin and its contents will become loam, a high-nutrient soil that nourishes the plant growing above.
Personally, I'd like to have a Tibetan sky burial, but that seems impractical...

2 comments:

  1. I'm not really convinced that freeze-drying is an ecological solution. Surely, lowering temperatures that far takes a lot of energy?

    I like the sky burial idea, but can't see that catching on or being given permission by the authorities. Then there is the shortage of vultures in most areas. And would you want to encourage bears and cayoties to get a taste for human flesh?

    My favourite method would be the shallow grave with a hemp shroud, but it has some of the disadvantages stated about burial. Taking up land could be mitigated by doing burials on recently felled woodland before replanting, or creating new woodland on waste land.

    How about solar kiln "cremation", where the body is cooked to a cinder? Could be like a large solar oven or parabolic mirror type cooker. Requires a bit more grinding up than the easy shatter disintegration of freeze drying, but at least the remains would be largely reduced and sterile from a public health point of view.

    Throughput would be limited due to the length of time it would take to process a body and because it would be weather dependent. It would still be a good way to take care of some bodies, especially in sunny areas.

    Maybe we should see burial in the same way that vernacular building evolved - whatever is appropriate in any given area.

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  2. Hi Judy, I've seen the solar heater funeral idea written about but I don't think it exists in reality... yet.

    As far as I know, the compressor motor on freezers don't take a lot of electricity to run, and if the power is generated by renewable methods, that should be almost zero carbon. The liquid nitrogen used in Promession (when it eventually happens!) is a waste product of the oxygen industry, so ordinarily it is just left to boil off back to the atmosphere, so Promession will actually reduce the carbon footprint of oxygen, if that makes sense?

    From what I've read, Promession seems the most ecologically sound method of disposing of a body, especially as it is returned to the topsoil, and doesn't pollute like a deep burial does, with the liquids leaching out to groundwater and methane venting out to the atmosphere.

    I'll go for Promession, if it's available before I die!!!

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