The optimal design of pressure swing adsorption systems

Abstract: "This work presents a model to determine the annualized cost optimal design of a pressure swing adsorption (PSA) separation system. Design decisions include the number of beds, the operations to use, the scheduling of those operations, and the operating conditions. Operations include adsorption, pressure equalization, blowdown, desorption, and feed repressurization. Operations can be interconnected such as pressurizing one bed by connecting it to another which is to be depressurized.The capital and operating costs and adsorption behavior of each operation in the operating sequence is approximated by a set of algebraic equations, which, due to the level of error in determining the physical properties, has been found to be sufficiently accurate to characterizethe system. The paper presents each of these operation models and the assumptions behind them. The structure of the model is a mixed-integer nonlinear program (MINLP), the solution of which determines the optimal operating configuration, size, and operating conditions. Designing an 'optimal' PSA system to remove methane from a hydrogen stream illustrates the approach."