Physical Factors

In addition to the preceding chemical factors, a number of physical factors have an important bearing on the chemical reaction. The most important of these are:

• Reaction pressure

• Reaction temperature

• Ratio of reactants

• Product workup

Most reactions occur under atmospheric pressure; while oxidation, hydrogenation, and some polymerization occur at higher pressures. The effects of pressure and temperature on equilibrium and the reaction rate are discussed in Section 3.7.

For capacity, feeding the reactants in their stoichio-metric ratio and at a maximum concentration is advantageous. However, if one of the reactants is relatively expensive, using the other, less expensive, reactant in excess produces a higher yield with respect to the former reac-tant. This method is especially effective when recovering the more expensive reactant from the product stream is difficult.

0 0

Post a comment