Hollow fiber membrane module for co2/ch4 separation: modeling, process simulation and design

The potential of membrane technology for the effective separation of carbon dioxide from methane has attracted significant attention over the past decades. Hollow fiber module is the most employed membrane module for gas separation industries with more than 80 percent of market share.
The performance of hollow fiber membrane has been described by different mathematical models, but there is limited work done in the field of process simulation, where mathematical models can be incorporated with other unit operations using commercially available simulators. Moreover, the available mathematical models are usually based on ideal assumptions such as constant membrane permeance (independent of temperature and pressure).
In this work, an experimentally validated non-ideal model has been developed and integrated in a commercial process simulator for hollow fiber membrane module, which would be used to evaluate the separation performance and economics of the system.
There can be different flow mechanisms for hollow fiber separation systems, but cross flow is one of the most applied mechanisms in the industrial applications. Thus, cross flow membrane model is developed and used to find the optimal design configuration. It has been shown that double stage with permeate recycle gives the most optimum design configuration due to minimum gas processing cost involved with it. Based on the optimal design configuration, the effect of module characteristics on the performance and economics of system has been studied.
Finally, non-ideal effects including Joule Thomson effect and temperature and pressure dependence of permeance have been incorporated into the developed model and compared with the ideal case. The result show that the variable permeance has significant effect on the product quality and gas processing cost, thus it becomes important to include the non-ideal effect in order to analyze the performance and economics accurately. The developed non-ideal model in process simulator can be used for the design, scale up and optimization of gas separation systems.