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Membrane Separation Polymer Ionic liquidIntegrated system a b s t r a c t Many types of membranes are available to enrich hydrogen. Nevertheless, there are some with special potential for biohydrogen purification such as the non-porous, polymeric and ionic liquid based membranes. The attractiveness of these membranes comes from the fact that they can be employed nearly under the conditions where biohydrogen formation taking place. Therefore, they appear as promising candidates to be coupled with hydrogen producing bioreactors and hence giving the chance for in situ biohydrogen concentration.It is known that the feasibility and efficiency of membrane technology e beside material selection and module design e significantly depend on the separation circumstances.Thus, the operation of membranes is a key issue and the most important factors to be considered for gas purification are the composition of gas to be separated, the pressure and temperature applied. The scope of this study is to give a comprehensive overview on the recent applications of non-porous, polymeric and ionic liquid supported membranes for biohydrogen recovery, placing emphasis on the operational conditions affecting membrane's behavior and performance. Furthermore, a novel concept for integrated biohydrogen production and purification using gas separation membranes is demonstrated and discussed.

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The application of ionic liquids as solvents for the enantioselective esterification of (R,S)-2-chloropropanoic acid with butan-1-ol using Candida rugosa lipase is reported. The role of water produced during the reaction and controlling of the water activity with pervaporation was studied. The enantioselective esterification of (R,S)-2-chloropropanoic acid with butan-1-ol in different organic solvents and ionic liquids was studied. The reaction was effectively catalysed by Candida rugosa lipase. From the ionic solvents investigated, the best results were achieved in [bmim]PF 6 . The presence of water had a strong effect on the activity of the lipase. Since in esterification reactions with acid and alcohol equimolar amounts of water are formed, the excess of water was removed and the water activity was kept constant using a pervaporation system without any additives. At the optimum water activity Candida rugosa lipase showed high thermal stability in [bmim]PF 6 and it could be reused for at least five recycles with only a small lost of activity.