[ExI] Space Based Solar Power vs. Nuclear Fission

[Brent Neal]

On 18 May, 2008, at 17:39, hkhenson wrote:
> It depends on what they are making.  Besides being burned to make
> electricity, coal (and oil) are feed stocks to make all sorts of
> things like plastics.

In terms of -power-, most american manufacturing plants are on the  
grid, however if your process has ovens or steamers or some such,  
those are usually gas-fired. In the global scale of things, a fairly  
small fraction of world oil is turned into plastic in the US. The LBL  
chart of US energy inputs and outputs shows this quite clearly. In  
2002, out of  ~41 exajoules worth of energy from petroleum used in the  
US, about 5.5 exajoules were used in non-fuel applications, and a  
fraction of this is the production of plastics. (Source: https://eed.llnl.gov/flow/pdf/USEnFlow02-exaj.pdf) 
  The economics of plastics production has pushed the major polymer  
reactor sites closer to large gas fields and oil fields - Saudi  
Arabia, Indonesia, etc.

It is also interesting that the two highest volume plastics by world  
production, polyethylene and polypropylene, are not sourced from crude  
oil, but from natural gas. Same with polyvinylchloride.  Polystyrene  
is the largest volume polymer that is synthesized from crude oil  
products (benzene from crude and ethylene from gas are reacted to form  
styrene) and all styrenics are under displacement pressures from  
olefinics - partially for this reason.

Amusingly, the production of PE and PP could be considered a green  
endeavor. When you drill a new oil well, you typically flare the  
natural gas off, contributing to atmospheric CO2. Its very wasteful,  
too, and folks are just now starting to use that gas to power the  
wells on site, but separating the methane for burning from the higher  
alkenes means that all of a sudden the Saudis and the Indonesians have  
the potential to make a whole hell of a lot of polyolefins. Still, the  
folk wisdom in the plastics industry is that the oilfield operators  
flare off more ethylene and propylene in a month than the plastics  
industry uses in a year.  :)

B


--
Brent Neal, Ph.D.
http://brentn.freeshell.org
<brentn at freeshell.org>