Recovery of monomethylhydrazine liquid propellant by pervaporation technique

Monomethylhydrazine (MMH) is a well-known liquid propellant used as fuel fo r launching of rockets and satellites. The desalted reaction liquor of MMH contains about 2 wt % of the propellant (balance water), which also forms a n azeotrope with water at 35% MMH concentration. Removal of water to obtain pure MMH by conventional separation methods such as distillation is hazard prone and expensive. The potential of the membrane-based pervaporation tec hnique has been investigated in this study for enriching aqueous solutions of MMK. Ethylcellulose membrane, which is selected on the basis of estimati ons of Flory-Huggins interaction parameters and Hansen's solubility paramet er, gives promising results and is resistant to chemical attack by MMH. The effect of operating parameters such as feed concentration and membrane thi ckness on flux and selectivity are evaluated. Finally aging studies have be en carried out to determine the life of the membrane in the propellant medi um.