how do I calculate how much co2 it takes to make a ton from CubicFoot?

You need more information, unless you assume STANDARD cubic feet (SCF), and even then you must define which standard is being used. As Wikipedia points out http://en.wikipedia.org/wiki/Scfm

there are many different "standards".

However, I'll assume the standard that I'm used to, that of 68F (20C, 293.15K) and 1 atm. First we need ideal gas law:

PV=nRT

We'll solve for number of moles per SCF (n):

n/V = P/RT

R for SCF, atm, K, and lb-mol is 1.31443

so:

n/v = 1atm/(1.31443 * 293.15K) = 2.595E-3 lbmol/SCF

Next, we convert to mass my using molecular weight of CO2 (44.0095 lb/lbmol):

m/V = MW*n/V = 44.0095 lb/lbmol * 2.595E-3 lbmol/SCF

m/V = 0.1142 lb/SCF

Since there are 2000 lb/ton:

m/v = 0.1142 lb/SCF * (1/2000)ton/lb

Therefore we get 5.710E-5 (0.00005710) ton of CO2 per SCF.

A nicer way to look at that would be SCF / ton, or 1/5.710E-5 = 1.751E4 SCF (1.751x10^4)

(Note: When I originally typed this, I was thinking "SCFM" standard cubic feet per minute because I use it all the time. I've tried to remove the "M" from everything since there was never any implied time, the answers don't change.)

EDIT: Note, I "lost" the "E4" part of the answer when typing. It has been corrected. Sorry.

Scf To Lbmol