Methods and systems are provided for the transportation of hydrogen including the use of a carrier medium and the subsequent separation of the hydrogen from the carrier medium upon delivery of the mixed gas stream to a desired location. In one example, up to approximately 20% hydrogen (molar fraction) may be mixed with natural gas and transported through a natural gas pipeline. The hydrogen may be separated from the natural gas by liquefying the natural gas and separating the liquid and vapor components in a gas-liquid separator to form a natural gas stream and a hydrogen stream. One or both of the separated streams may be used in cooling of the mixed stream. Precompression and expansion pressure of the various streams may be used to influence the purity level of the hydrogen. Other constituents, or impurities, present in the mixed gas stream may also be removed as may be desired.
 The United States Government has certain rights in this invention pursuant to Contract No. DE-AC07-05ID14517 between the United States Department of Energy and Battelle Energy Alliance, LLC.