Abstract: A fiber reaction process whereby reactive components contained in immiscible streams are brought into contact to effect chemical reactions and separations. The conduit reactor utilized contains wettable fibers onto which one stream is substantially constrained and a second stream is flowed over to continuously create a new interface there between to efficiently bring about contact of the reactive species and thus promote reactions thereof or extractions thereby. Co-solvents and phase transfer catalysts may be employed to facilitate the process.