Gas permeation test equipment

The equipment can be used to test the gas permeation membranes at the pressure up to 20barg. The most important features of the equipment are:

  • preparation of N2/CH4/CO2/CO/H2 gas mixtures by means of Mass Flow Controlers
    (up to 5l/min each)
  • measurement of pure gas permeabilities using Mass Flow Meters
  • thermostatic chamber
  • NDIR gas analysis for CO2 and CH4
  • industial PLC with an HMI/SCADA system for tests control and data collection
    (GE-FANUC™ systems)
  • immediate cocurrent, countercurrent and sweep configurations

FVM mass transfer models for the detailed simulation of membrane processes

Models for the species transport through membranes were written in C programming language and implemented in the commercial FLUENT™ solver. The models allow detailed simulation of the flow in membrane modules. The figure below presents some results obtained from the model: the concentration of sodium chloride on the both sides of the membrane in the vicinity of the spacer in a reverse osmosis process

Dynamic modelling of the multi-stage gas permeation systems

In order to facilitate the design and optimisation of the control system of the two-stage gas permeation biogas upgrading plant, a new one-dimensional dynamic process model has been developed. It is based on the advection equation that is discetised using finite volume method and solved using an explicit solver. The model has been written in C++ programming language and connected to the SIMULINK/MATLAB™ environment so that other useful blocks of the software package can be used together with the model

Numerical algorithm for modelling multicomponent multipermeator systems

The presented algorithm allows calculation of multicomponent gas separation in hollow-fibre membrane modules in co-current, counter-current and cross-flow configurations. The permeators can be combined in any system with recycles. The algorithm is based on the finite difference Gauß–Seidel method. The solution of the system can be stabilised by means of adaptation of the relaxation factor in case of difficulties with convergence. The performance of the algorithm was evaluated in terms of the required number of iterations and computational time for a number of single permeator and multipermeator separation problems. The counter-current configuration with component gases having high selectivities required the most computational time.

The permeation of a biogas-like gas mixture consisting of three components: methane, carbon dioxide and oxygen was modelled and compared with an experiment. The results of the modelled gas separation were found to be in good agreement with the measured values. The highest performance was achieved by the counter-current configuration.

Figure: Flowsheet of the experimental setup