Modelling and optimization of single and multi-layer pressure swing adsorption system
Systematic methods and tools for managing the complexity
Tools Integration - CAPE Methods & Tools (T4-10P)
Keywords: Pressure swing adsorption, gas separations
A generic modelling and optimization framework for separations of gas mixtures using multibed pressure swing adsorption systems is presented. The framework relies on a systematic approach for the automatic generation of the underlying flowsheet (all feasible bed interconnections and their topology) and complex operating procedure for a given number of beds. Important features of the framework also include four different mass balance theories, three thermal operating modes, single or multiple layers of adsorbents and complex, gas valve controlled bed interactions. All models have been implemented in PSE’s gPROMS modelling environment.
The framework has been employed in a separation of hydrogen from steam-methane reforming off gas using single and multi-layered adsorbents. The impact of single and multilayer activated carbon and zeolite adsorbents on the process separation efficiency has been investigated. The effect of number of beds on the product quality (purity and recover) has been analysed and trade-offs between capital and operating costs are revealed. Furthermore the effect of operating conditions as well as the design characteristics of the adsorption column on the overall efficiency of the PSA flowsheet have been critically discussed (such are duration of operating steps, feed pressure, particle radius, feed and purge gas flowrates, column length and diameter, and carbon-to-zeolite ratio). Then, a formal optimization approach has been employed to optimize the design and operating conditions of the underlying PSA systems. Two different problems have been addressed: (i) to minimize the energy consumption per product unit for a given adsorbent productivity and minimum requirements in product purity and recovery; (ii) to maximize product purity and recovery for a given adsorbent productivity and column geometry while optimizing the operating characteristics of the process and the distribution of activated carbon to zeolite adsorbents in the bed(s).
Presented Thursday 20, 13:30 to 14:40, in session Tools Integration - CAPE Methods & Tools (T4-10P).
