A process and an apparatus are disclosed for a compact processing assembly to fractionate lighter components from mixed hydrocarbon streams. The hydrocarbon stream is supplied to the processing assembly between an absorbing means and a mass transfer means. A distillation vapor stream is collected from the upper region of the absorbing means and cooled in a first heat and mass transfer means inside the processing assembly to partially condense it, forming a volatile stream and a condensed stream. The condensed stream is supplied to the absorbing means as its top feed. A distillation liquid stream is collected from the lower region of the mass transfer means and heated in a second heat and mass transfer means inside the processing assembly to strip out its volatile components, forming a relatively less volatile stream and a vaporized stream. The vaporized stream is supplied to the mass transfer means as its bottom feed.