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Re: honeycombs
Posted:
Jan 23, 2013 5:27 PM


On Jan 22, Salmon Egg <Salmon...@sbcglobal.net> wrote: > > > I saw a news item about a new technique to draw CO2 from > > > the atmosphere. It's a chemical process, using amines, > > > which binds with the molecule, coated on a large structure, > > > in the shape of a honeycomb. > > > > According to the story, this maximizes surface area. > > > ok, mathematicians, which function gets optimized by a > > > honeycomb? What are the constraints and assumptions? > > > 2D problem to *minimise* the surface area to occupy a given volume. Bees > > use it to make honeycomb with the least amount of wax. > > > It is not difficult to show that the angle between sides must be 120 > > degrees and that equal lengths minimise total length/area occupied. > > > They have the structure just about as wrong as it is possible to be > > unless the stuff they are making it out of is extremely precious. > > > The 3D problem to occupy volume with a foam of minimum surface area is > > far more interesting and gives rise to Plateau's laws of soap films. The > > Kelvin foam structure was optimal until fairly recently when > > WearePhelan discovered a 3% better solution using a pair of shapes. A > > whole new family has been found but as yet a proof of optimality eludes. > > This concept of honeycomb is crazy. True, the area of the honeycomb is a > relativity efficient way of getting large reactive area to convert CO2 > to something that can be safely sequestered. > > How are you going to get the zillions of tons of amines the OP thought > would be a suitable reactant? How much CO2 is sent into the atmosphere > to prepare the amines? The honeycomb math problem is a red or even > infrared herring.
The chemistry, I don't know. I was asking about the optimization problem.
Anyhow, the inventor, Global Thermostat, has funding, and a working prototype.
 Rich



