Here we recall what we learned or could have learned in chemistry class. We see a chemical equation that shows carbon monoxide, CO combining with hydrogen, H₂ to make a hydrocarbon of unspecified chain length and some water. This is the Fischer-Tropsch condensation defined. (Carbon monoxide mixed with hydrogen is what producer gas is made of. ) Below that is another chemical equation showing how one unit of carbon monoxide can combine with one unit of hydrogen to add one additional unit of methylene group to an already existing carbon chain. The unit is the mole which is about 22.4 liters of gas at near room temperature. At the right we see that this reacton gives off 165 thousand watt-seconds of heat per mole of carbon monoxide consumed. Imagine all this heat suddenly being generated in a 22 liter bag of gas. Table 7 shows five alternative reactions which have about the same effect. In real life, all these and many more chemical reactions go on at the same time in the process. Since most of these reactions are exothermic, the heat must be collected and preferably used to do something useful. Looking at the first equation at the top, we see that the volume of gas on the left is substantially larger than the volume of gas and liquid on the right. By LeChatlier’s principle, which says that things in general when they are in an equilibrium state adjust the equilibrium to lessen any applied stress, we can see that higher pressure will drive the reaction to the right giving longer chain hydrocarbons.