Hydrogenation of crotonaldehyde under periodic flow interruption in a trickle bed

The conversion and consumption rate of crotonaldehyde under steady operation (constant liquid flow) and periodic operation (on-off liquid flow) at 25 degrees C and 1.1 MPa pressure were compared at equal time-average liquid flow rates. Steady experiments showed the effect of liquid flow rate on conversion and consumption and also provided kinetic data. Liquid flow rates were varied over approximately two orders of magnitude. Periodic experiments involved studies of the effect of period length, period split and flush amplitude on time-average conversion and consumption rate. The periodic operation data were compared with steady operation data on a time-average liquid flow rate basis. The comparison showed that. for higher liquid flow rates both conversions and rates of consumption under periodic operation were less than those under comparable steady operation. However for lower liquid flow rates (0.04-0.4 kg/(m(2) s)), the opposite occurred, with periodic operation showing up to 50% increase in the crotonaldehyde consumption rate. (C) 1999 Elsevier Science Ltd. All rights reserved.