In one aspect, the crude gas is contacted with a cold caustic solution to reduce levels of carbon dioxide and water. The partially purified gas is chilled in direct-contact with a hydrogen refrigerant to induce homogenous condensation of water impurity. Liquid and ice particles formed by lower temperatures are removed across an aerosol phase separating medium to produce a cooled and partially purified gas mixture which is further dried and de-carbonated across a zeolitic molecular sieve adsorbent to achieve very low concentrations of moisture and carbon dioxide in the bulk gas. In one aspect, the purified gas mixture obtained is partially liquefied, phase-separated and distilled to obtain germanium hydride, digermanium hexahydride and hydrogen gas as products. A portion of the hydrogen product can be compressed, chilled and re-used as a direct-contact refrigerant in the purification process.