Regarding reactor size,for a given duty and a constant volume system,an element of fluid reacts for the same length of time in the batch and in the plug flow reactor.Thus, the same volume of these reactors is needed to do a given job. On a long-term production basis we must correct the size requirement estimate to account for the shutdown time between batches. 33 • Regarding reactor size, for a given duty and a constant volume system, an element of fluid reacts for the same length of time in the batch and in the plug flow reactor. Thus, the same volume of these reactors is needed to do a given job. • On a long-term production basis we must correct the size requirement estimate to account for the shutdown time between batches