Abstract: The present invention relates a process for separating H2, preferably both H2 and CH4, from a gas mixture comprising H2 and CH4 by means of a series of selective membrane units that avoids compressors and vacuums as well as an apparatus for carrying out said separation.

Abstract: Disclosed herein is a process for preparing biodegradable microparticles comprising a biodegradable polymeric binder and a biologically active agent, wherein a blend of at least two substantially non-toxic solvents, free of halogenated hydrocarbons, is used to dissolve or disperse the agent and dissolve the polymer. The solvent blend containing the agent and polymer is dispersed in an aqueous solution to form microdroplets. The resulting emulsion is then added to an extraction medium preferably containing at least one of the solvents of the blend, whereby the rate of extraction of each solvent is controlled, whereupon the biodegradable microparticles containing the biologically active agent are formed.