Re: [Traveller_TNE] Low Tech Stuff

On 19 May 2007 at 6:58, Gerry Harris wrote:

> At first, I was stuck with two fuel sources from FF&S: alcohol and
> wood. I managed to work out the stats for "wood gas" when I
> stumbled across doing research on steel:

> http://en.wikipedia .org/wiki/ Wood_gas

> Mass and price would be the same as for hydrocarbon distillates, but
> the power output would be divided by eight. Not a particularly
> attractive technology, and it doesn't solve the deforestation
> problem, which on our world was fixed by the increasing use of coal.
> Alcohol, of course, eats into the food supply so it's not going to
> be super popular, either, although it would be used to a greater or
> lesser extent.

Actually, the best best is controlled pyrolysis of the wood, giving
you charcoal (better for metallurgy) and a lot of distillates. The
distillates include methanol which can be burned, and a number of
useful chemicals.

One trick is that you can make alcohol from the *inedible* parts of
the food plants.

Alas, if the planet has been terraformed, ypu can really afford to do
either. Not until you've got a few centuries worth of excess biomass
sitting around. To say nothing of the fact that you won't have that
much excess *oxygen* until you have a lot of carbon locked up in
biomass and the like.

> Peat is available, but I cannot find stats on its energy density.

Peat isn't going to be available in useful amounts either. It takes
*centuries* to build up a decent peat bog.

> On the plus side, as near as I can tell, steel should be available as it has a low carbon content, and that could be supplied by charcoal.

Except it takes a lot of carbon in the form of charcoal or coke to
produce the iron from the iron ore..

BTW, if the world has only been terraformed for a few hundred years,
erosion is gonna be interesting. For example, the rocks are going to
be oxidizing for millenia. Earth has a thick layer of deposits of
what amount to *rust* from when the atmosphere switched from reducing
to oxidizing.

The rivers and streams will be carrying a lot of iron oxide. In fact,
a lot of normal mineral deposits are due to this and to biological
activity (various sorts of bacteria working on metal ions to produce
the sulfide ores)

If the planet had *no* life then its geology is going to be a major
pain when it comes to mining.

If it just had primitive life in the seas (say only single cells, and
on photosynthesis) you'll have some ores, but not others. And burning
things for power will not be *allowable* as you won't have enough of
the carbon from the original CO2 "sequestered" .

And so on.

> If any of y'all have any ideas for fuels, limitations on technology
> because of the lack of fossil fuels, or clever workarounds for some
> of those limitations, I would appreciate hearing your ideas.

Besides hydroelectric, you'll have a lot of solar. Most using "mirror
farms" to focus sunlight on a boiler.

Remember that on earth, sunlight is good for roughly 750 watts per
square meter. Of course, they'll be lucky to harvest even 50% of
that, but still...

A square kilometer of mirrors might be able to produce as much as 50
megawatts. Let's assume really low efficiency (partly due to the need
to leave space between the mirrors and the need for power to steer
them so they track the sun. So call it only 10 megawatts. And that
during only part of the day. (lower power early and late in the day,
plus clouds and the like).

They'd need to store it as well because of the variation. The dialy
output might only average 1 MW.

Aluminum might actually be easier to extract than iron, since the
energy mostly comes from electricity. While carbon *is* used up, it's
probably easier to replace since it's a lower amount.

This will have implications for the world and tech in general.
--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com