Ratio Of Membrane Area Research Articles

Porous membrane reactors for hydrogen sulfide splitting

The potential of porous membrane reactors has been examined for a particular application: the hydrogen sulfide thermal-catalytic decomposition reaction. A model has been proposed in which the reaction products and the remaining reactant are at thermodynamic equilibrium. The possibility of membranes as disturbers of this equilibrium has been studied, assuming a complete stirred tank reactor or mixed flow reactor (CSTR). Results show that membrane CSTR conversions become more attractive as the operating temperature increases. At 1100 °C, the membrane CSTR conversion provides 9.2% of additional conversion, compared with the conventional CSTR. Also, it is shown that both the feed pressure and feed flow to membrane area ratios are operating variables needing to be optimized. This optimization is dependent upon the membrane's particular permeability characteristics.

Gas separation in an internally staged permeator: experimental results and theoretical predictions

An internally staged membrane permeator was assembled using a silicone rubber membrane in the laboratory. Separation of CO 2 N 2 using this permeator was studied experimentally and theoretically. It has been shown experimentally that simultaneous use of two membranes of the same type in a permeator improves the degree of separation to the level which may not be possible to achieve in a single stage permeator. The mathematical model based on the perfect mixing case predicts the experimental results very well. The simulation results have shown that, in order to maximise the degree of separation, the values of both stage cuts and the pressure ratio across each membrane have to be properly selected to obtain the optimal operating conditions. At these conditions, the membrane area ratio between first and second stage decreases with increasing overall stage cut.

Analysis and optimization of a reverse osmosis water purification system—part II. Optimization

A mathematical model of a reverse osmosis water purification system that can be used in process optimization studies and cost equations that relate the capital and operating costs to the design variables is developed in Part I of this work. In this part, the model is used to determine design and operating variables of the system, which minimize the cost of water production. Several three multistage reverse osmosis systems are considered. They are a multistage operation without the use of a flow-work exchanger and with a variable membrane area at each stage (System 1), that with equal membrane area at each stage (System 2), and a multistage operation with the use of a flow-work exchanger and with variable membrane area at each stage (System 3). In the optimization study, the recirculation rate in each stage, the brine composition leaving each stage, the ratio of membrane area to feed at each stage, and the operating pressure in each stage are controlled to arrive at a minimum water production cost.