A process for removing a foulant from a gas stream is disclosed. The gas stream, containing a foulant, is cooled across a first heat exchanger and a second heat exchanger, producing a solid foulant entrained in cryogenic liquid as a foulant slurry, and a foulant-depleted gas stream. The foulant-depleted gas stream is passed through a cryogenic turbine and a first separation vessel, producing a light gas stream and further solid foulant. The solid foulants are recovered by a combination of pressurization, melting, and distillation to produce a liquid foulant product. Heat is recovered from the various streams in the various heat exchangers and the melter.