Apparatus for contacting first and second fluids at elevated pressures
with a membrane such that one or more components of one of the fluids passes through
the membrane into the other fluid, comprising a housing e.g. a pressure vessel
(4), and a membrane module (20) housed in the pressure vessel and
having a first fluid inlet (8a) and a first fluid outlet (8b)
and a second fluid inlet (9a) and a second fluid outlet (9b),
wherein a seal (61) extends round the membrane module and seals between
an outside wall of the membrane module and an inside wall of the pressure vessel
so as to separate the first fluid inlet from the first fluid outlet.