In the acrogenic process introduced in Problem 15.1, the catalyst is packed in tubes and the reactor is cooled using a circulating molten salt. The molten salt rejects heat to boiling steam in a similar arrangement to that shown for phallic anhydride in Figure 15.25. The required gas hourly space velocity is 200 standard liters (at STP)/liter.h. Design and size a reactor to produce 20 kt/y of acrogenic.
Problem 15.1
Acrolein (H2C=CHCHO) is made by selective oxidation of propylene at 2 bar, 350 °C using a molybdenum, iron, and bismuth catalyst on a silica support. The reactor yields based on propylene are 85% acrolein, 10% acrylic acid, and 5% light by-products. The light byproducts are mostly acetaldehyde, but for the purpose of this problem it can be assumed that the yield is 85% acrolein and 15% acrylic acid. The feed to the reactor on a volume percent basis is propylene 6%, propane 28%, steam 6%, oxygen 11%, and balance nitrogen. Estimate the reactor cooling requirement for a plant that produces 20,000 metric tons per year (20 kt/y) of acrolein if the reactor is operated isothermally.